Method and system to control rod travel in system pumping fluid out of well
FIELD: engines and pumps.
SUBSTANCE: invention relates to oil production, particularly to oil rod-type pumps. Maximum pump travel and shortest cycle time are calculated proceeding from all statistical and dynamic characteristics of downhole and surface components, primary motor angular speed being unlimited. Restraints, as to structural strength and fatigue strength, are used in optimisation calculation to ensure safe operation at maximum pumped volume and minimum power consumption. Primary motor designed optimum speed is set for rod pump with the help of jack balance beam, major-travel unit or hydraulic pumping unit. It can also be set by controlling primary motor rpm, acceleration and torque, or by adjusting pressure and flow rate in pump system.
EFFECT: optimised rpm of rod pump primary motor, maximum increase in oil extraction and lower operating costs.
18 cl, 6 dwg
The scope of the invention
The present invention in General relates to the creation of methods and systems for maximum pumping fluid from the well with the use of the pumping system with pump rods, and more particularly to the creation of methods and systems for maximum production of fluid by optimizing the speed of the primary engine of the pump rod.
Prerequisites to the creation of inventions
Reciprocating oil pumps traditionally controlled by the pumping unit with balance trim with sinusoidal characteristics of the reciprocating motion of the polished rod pumping unit, which is dictated by the constant speed electric or gas primary engine and the geometry of the pumping unit with Centerpoint trim. Usually use a constant speed of the crank during operation of the pumping unit with Centerpoint trim. In the geometry of the pumping unit with Centerpoint trim dictates the speed of the pump rod, the next curve, which is sinusoidal in nature. Other types of pumping units, such as blocks of pumping with long-stroke or with hydraulic control, work on the first constant speed of the polished rod during run-up and the second constant is karasti during turn down with the additional speed change only during the change of direction. In some pumping units use variable control of the primary engines to facilitate change constant speed primary motor or to allow selection of the variable speed primary motor at any desired segment of the pumping cycle.
Normal evacuation system with pump rods includes surface equipment (machine-rocking with Centerpoint trim or rocking simplified type for deep well pumps working group drive), and downhole equipment (pump rod and pump), which operates in a well bore drilled into the oil reservoir. The interaction of moving and stationary elements of the well and the dynamic interaction with the fluids present in the well, creates a complex mechanical system that requires precise design and management, to be able to work effectively.
To increase oil production it is necessary to analyze and optimize all elements of the pumping system with the use of sucker rods. System design equipment oil well is usually carried out on the basis of the laws of mechanics and special techniques, and you need to use specific set analysis is practical standards to create a successful project and desirable operation of oil wells. This analysis typically includes:
1. Dynamic analysis of the system of rods, when the calculation of dynamic forces and stresses acting on the pumping rod (dynamic wave equation);
2. Kinetic analysis of the surface equipment (pumping unit);
3. Performance analysis of a submersible pump (program for the evaluation wells); and
4. The performance analysis of the oil layer (communication with the characteristics of the influent).
This is already known systems analysis provides the correct and useful information about initial well design and its performance, but only for a constant speed Prime mover. Previously known attempts to improve well production envisaged change component columns of the sucker rods and pump size, changing full speed rotation of the crank, speed regulation during the course by choosing different constant speeds of the crank to move up and move down by means of a variable speed drive or through the use of motors with ultra-glide to slow the speed of the primary engine during periods of peak torque in the same turn. We already know that you can change the speed of the primary engine is to control the modes of pumping (U.S. patent No. 4,490,094; 4,973,226 and 5,252,031; the latter is based on the calculation of the characteristics of a submersible pump contained originally in U.S. patent No. 3,343,409), while limiting the load on the column rod connecting surface unit with a reciprocating pump and other components (U.S. patent No. 4,102,394 and 5,246,076; PCT publication WO 03/048578), and also known optimization modes pumping unit pumping (U.S. patent No. 4,102,394 and 4,490,094) or the conversion characteristics of the sinusoidal speed of the polished rod, managed by the pumping unit with Centerpoint trim, linear response over most moves up and moves down (U.S. patent No. 6,890,156)to simulate the long course of a typical rocking simplified type.
Most of the previously known methods and systems based on different analyses of loads or energy of the polished rod and on the indirect detection of various problems associated with the mode of operation of the pump or fluid influx into the well. In U.S. patent No. 4,102,394, for example, it is proposed to install a different constant speed primary motor during the running up that is different from the speed during move down to arrange the flow of oil from the reservoir and to avoid empty modes pumping. The method proposed in U.S. patent No. 4,490,094, determines and modifies the instantaneous MSE of the ity of the primary engine for a given section of the stroke of the polished rod, on the basis of the output power and operation of the primary engine. In PCT publication WO 03/048578 described the use of the final changes to the speed of the primary engine in the same turn, in order to limit the impact load on the polished rod within predetermined safe limits. In U.S. patent No. 6,890,156 described the use of the final changes to the speed of the primary engine, so the speed of the polished rod, which makes a reciprocating motion by means of a pumping unit with Centerpoint trim, it remains constant over an extended period during the move up and move down. Speed changes are dictated by the geometry of the pumping unit with Centerpoint balance and lead to a decrease in the operating time when the same maximum speed of the polished rod. No communication with the effective stroke of the pump and there is no impact on the effective stroke of the pump, is not taken into account or intentionally does not change the maximum or minimum force acting in a string of sucker rods.
For the past ten years, various providers offer variable speed drives (VFD) for pumping units with Centerpoint trim that gives the possibility to change the speed of the crank and the polished rod during one stroke of the pump. Some the e device, such as IRAs Flux Vector Drive company eProduction Solutions or Sucker-Rod Pump Drive company Unico, Inc., allow the user to set the variable speed of the crank and the polished rod during the same turn using the built-in programmable logic controller and used in the industry chain programming language.
In previously known solutions, the speed of the polished rod was changed in order to improve, but not to optimize certain aspects of the operation of the pump, for example, to reduce the load in the column rod, or such decisions were focused rather on the kinematics of the pumping system and prescribed certain movement of the polished rod, without analysis of the dynamics of the entire system containing surface block, rod string and a submersible pump.
To date, the optimization process was used only at the design phase, where, on the basis of system requirements and dynamic analysis of all of the pumping system, was determined by the physical parameters of the system (such as the engine, the materials and dimensions of the column sucker rods and the like)to obtain the desired flow rate and not to exceed the maximum load applied to the system. However, this optimization when designing involves the use of a constant speed Prime mover.
When trying to improve the design, the tion of a new pumping system or improve an existing system, no attempt was made to optimize its characteristics by optimizing the period of the course and by changing the speed of the primary engine for the turn. However, implementation of such an approach gives the possibility of creating a method and system that not only meets the highly nonlinear nature of the problem of optimization of oil production, but at the same time reduce operational costs and ensure safe load factors.
In accordance with the present invention offers a method and system for optimizing the speed of the primary engine pump to maximize oil production, while reducing operational costs and ensure a safe load factors. Optimization can be done for existing pumping systems and also in the development phase of the new system. The proposed method and system optimization focused on finding and applying the best variable speed Prime mover. However, it should be borne in mind that the obtained optimal angular speed of the primary engine determines the optimal linear speed of the polished rod, so after minor changes which will be familiar to specialists in this area - the proposed method can be also used is an optimization of the speed of the polished rod instead of the angular speed of the primary engine.
The present invention also allows you to automatically monitor, analyze, check, optimize and manage this well from a remote Central location. The proposed system is able to perform kinetic and dynamic analysis of equipment for oil wells and use a variety of experimental data and mathematical modeling to optimize well performance. Additional benefits include a current control modes of the pumping and detection of unusual, degraded or harmful modes, and change settings of pumping in response to detected changes.
In accordance with the first aspect of the present invention, it is proposed a method of controlling the angular speed of the primary engine and the movement of the polished rod in the evacuation system, and the method includes the following operations:
a) develop a mathematical model of the pumping system based on system data;
b) measuring the physical modes of the pumping system during operation;
c) comparison of the mathematical model and the measured physical regimes;
d) the calculation of the optimal variable speed primary motor and new operating parameters to determine the optimum movement of the polished rod, sucker rod pumps and submersible pump;and
e) application of optimal variable speed primary motor and new operating parameters in the system pumping.
In accordance with the second aspect of the present invention, a control system of the movement of the polished rod in the evacuation system, and the movement of the polished rod created by the primary engine, while this system contains:
a) surface pumping components, including the primary motor;
b) a controller for controlling the primary engine, and the specified controller allows dynamic changes of speed, acceleration and torque over one cycle;
c) downhole pumping components, including rod string and a submersible pump;
d) means for transmitting movement of the primary engine to the downhole components of the pumping;
e) means for measuring components in the surface pumping for controlling operating modes;
f) local control unit;
g) a means for transmitting signals intended for transmission of signals from the measuring devices and the controller, local control unit, to determine the optimal speed of the primary engine and the required new working parameters of the primary engine; and
(h) means for transferring the new operating parameters to the controller.
In the accordance with a preferred variant of the method in accordance with the present invention, optimal variable speed Prime mover define (set) so that the length of stroke of the pump becomes maximum, the running time becomes minimum, the forces acting on components of the pumping system, become the minimum, and the power consumption becomes minimum. Mainly, the calculation of the new operating parameters contains the analysis of the geometry and mechanical characteristics of the pumping system, and, when the primary engine creates the movement of the polished rod (and when to use the new operating parameters of the primary engine for optimal movement of the polished rod), then the primary engine receives new operating parameters by controlling the speed, acceleration and torque of the primary engine. When the evacuation system is a system of pumping hydraulic, new operating parameters of the pumping system is mainly set by regulating the pressure and flow rate in a control system of the pumping system. Optimal variable speed primary motor can be achieved by optimization technique selected from the group comprising theoretical methods, experimental methods and the combination of theoretical and experimental methods, and these methods known to experts in this region is among the the calculation of the optimal variable speed primary motor can be performed as part of the initial design of the pumping system, using the method of predictive analysis (without measuring the physical modes of the pumping system).
In accordance with a preferred variant of the system in accordance with the present invention, use measurement tools to measure the load of the polished rod, the position of the balance weight, the pressure in the tubing string and casing pressure, and these measurement tools mainly include a transducer for measuring the load of the polished rod, the optical position sensor for measuring the position of the balance weight and pressure sensors for measuring pressure in the tubing string and casing pressure. The controller may include a dynamic brake resistor or regenerative module, but none of them are mandatory. The system mainly contains remote computing station having communication with the local control unit. The local control unit mainly contains the utility of mathematical modeling and a variety of decision tools for signal analysis, determine the optimal speed of the primary engine and determine the required new operating parameters env the ranks of the engine.
In accordance with some preferred variants of the present invention, the evacuation system allows you to adjust the linear speed of the polished rod in accordance with a programmable or semipreparative a function of one of the following variables: time, position of the polished rod or angle of rotation of the crank. In accordance with these preferred variants of the present invention use a VFD to control the angular speed of the primary engine that allows you to get the optimal variable linear speed of the polished rod.
The most effective is the assumption that the profile of the angular velocity of the primary engine can be controlled by using the function Ω(s) position of the polished rod, however, this function can also be determined as a function of Ω(t) of time or function Ω(α) angle of the crank. S ε (0,s0) polished rod is determined for the entire cycle, which includes the move up and move down, and so socorresponds to twice the length of the stroke of the polished rod. In accordance with the present invention offers a method and system for optimizing the profile of the angular velocity Ω of the primary engine for the loop the whole time to solve one of the following tasks:
(I) the maximum increase in oil production; or
(II) the achievement of a given the first flow rate using a minimum of energy consumption in the pumping unit, however, when satisfying the following constraints during the entire period T of the passage:
(A) the maximum and minimum voltage at any point x ε (0,L) along the entire length L of the column of rods does not exceed the limits allowed under the modified scheme Goodman:
where g(σmin(x)) depends on the material properties of the segment of the rod at the point x;
(C) change the motor speed is achievable for a given pumping unit, that is, the torque M(Ω, s) does not exceed the permissible limit (Mmin, Mmaxspecified for the engine and gearbox:
where Mmin<0 is the minimum allowable negative torque (which may be zero, in order to minimize the regenerative torque),
moreover, the angular speed of the motor does not exceed the defined limit value:
Ω(s)<Ωmaxfor s ε (0,s0)
(C) angular velocity Ω(s) is the same at the beginning and the end of the turn due to the cyclical characteristics of the pumping operation:
Due to the internal delay time of angular velocity of the engine relative to the input signal from the VFD, the resulting motor speed does not match the input IC design shall grow, and so it is more efficient direct optimization of the input speed than first finding the optimal speed of the engine, and then attempt to determine the input function that actually creates the desired motor speed. Therefore, the function Ω(s) describes rather the optimal design of input speed to the VFD controller than the actual optimal speed of the engine. It should be borne in mind that the optimization of the input speed of the VFD is equivalent to controlling the speed of the polished rod to optimize the performance and operation of the pump.
It was observed that the optimal solution which maximizes the production rate, additionally provides the following advantages:
- Energy consumption and the maximum voltage across the pumping system is less than the profile for optimal speed Ω(s)than for movement in the same period of the cycle at a constant motor speed is equal to the average speed of the engine in the cycle variable speed.
- When using energy optimization to achieve the desired flow rate, the voltage is reduced in comparison with the movement during the same period of the cycle at a constant speed of the engine.
After determining the optimal input speed VFD, further reducing the torque and power of the engine are due to the adjustment of the weight distorting the spine to new modes of operation.
When conducting the optimization is not for the existing system pumping, and during the design phase, then the project can be further improved on the basis of the power requirements and load obtained using the speed of the primary engine is determined by the optimization process. Project modifications for improvement of the system performance, driven by means of the primary engine with optimal variable speed, for example, increasing the diameter of the weakest segments of the column rod can further improve the operating parameters of the system, when applied repeatedly processes optimization project of the pumping system and the speed of the primary engine.
It should be borne in mind that the optimum speed of the primary engine and the resulting speed of the polished rod, defined in accordance with the present invention differ from those prescribed in the previously known solutions. For example, in U.S. patent No. 6,890,156 described regulation of the speed of the primary engine to obtain a constant speed of the polished rod during the greater part of the stroke length (which is not necessarily optimize the flow rate and reduces the load), while the optimal movement of the polished rod received in accordance with the present invention, is usually not permanent is.
To overcome the limitations of the prior art, in accordance with the present invention produce an analysis of the current characteristics and the corresponding calculation and apply the most preferred variable speed Prime mover, to maximize the extraction fluid using the existing system pumping with pump rods. In some previously known systems need to change system components, to get any increase in production volume, as otherwise deteriorate the security modes when attempting to increase the constant speed of the Prime mover. Operating costs also increase because of the need to use larger components and increase energy consumption.
As in the previously known solutions, the measurement surface dynamogeny give the displacement of the polished rod and the force in the polished rod, which allow to calculate the following quantities, which are important from the point of view of optimization:
- efforts and voltage across the string of sucker rods, which are used to check conditions (A) the optimization process;
effective stroke length of the plunger, which is used to estimate the output flow rate of oil, which should be increased in accordance with the problem (I) optimization or the which must be set equal to a flow rate in accordance with the problem (II) optimization.
Measuring the torque of the engine create controls condition (C) of the optimization process. Measurement of angular velocity can be used to model the delay between the input speed of the VFD and the profile of the actual speed of the engine, if mathematical modeling is used instead of the physical measurements to find the response of the system pump/well at a given input speed of the VFD. Calculations stroke and voltages in a string of pump rods on the basis of measurements of surface dynamogeny carried out using the methods described in the literature, which use the finite difference method or the Fourier transform (see, for example, U.S. patent No. 3,343,409). Calculations stroke and voltages in a string of sucker rods, as well as loads on the surface of the block, including torque of the engine, the alternative can be carried out without using measurements of surface dynamogeny, namely by simulating the response of the column rods imposed on the movement of the polished rod, using advanced predictive analysis based on the original work of Gibbs (S.G.Gibbs, "Predicting Behaviour of Sucker-Rod Pumping System", Journal of Petroleum Technology (SPE 588. July 1963). This approach may give less accurate results, but it is necessary that e is any physical tests cannot be conducted or the results of the measurements cannot be accumulated, for example, during the design phase, or if the number of trials should be limited to minimize interruptions of the production of the well.
The present invention is directed to such a control speed of the primary engine, in which the polished rod moves so that the submersible pump performs reciprocating motion in any stroke length, which is required to maximize the production rate, when the fatigue loads in the pump rod below the maximum allowable. In addition, you can specify any desired speed submersible pump and the respective operation modes, to avoid excessive friction, gas tube or other harmful modes in the well.
These and other features of the invention will be more apparent from the subsequent detailed description, given as an example having no limiting character and described with reference to the accompanying drawings.
Brief description of drawings
1 schematically shows a system in accordance with the present invention.
On figa and 2b shows the precedence diagram illustrating a preferred process for use in developing software for the variant in accordance with the present invention.
Figure 3 shows a graph of the angular velocity of the primary engine is on and after optimization.
Figure 4 shows the linear speed of the polished rod before and after optimization.
Figure 5 shows a graph of the efforts of the polished rod and effort plunger pump relative movement during operation of the pump at a constant speed primary motor and optimized speed of the primary engine.
Figure 6 shows a graph of torque gearbox before and after optimization, the condition of optimization is to minimize the regenerative torque acting on the gearbox.
DETAILED description of the INVENTION
We look first at the above summary of the invention in which the problem (1) optimization is defined as the presence profile of the input angular velocity Ω(s) of the VFD, which maximizes the average volume of fluid pumped per unit of time. The volume pumped during the same turn due to imposed inlet velocity Ω(s) VFD equal to:
where ρ - sectional area of the plunger,
η is the coefficient of efficiency of pumping,
Uρ(Ω) plunger stroke (product ηUρ called the effective length of the course).
Therefore, the optimization problem, which is to ensure the maximum flow rate per unit time, can be mathematically defined as finding the profile Ω(s) the initial speed of the VFD, which brings up to a maximum of the functional V(Ω), but with the satisfaction of constraints (a-C):
where T(Ω) represents the period of the course, obtained by applying the input rate Ω(s).
Similarly, the problem (II) optimization can be defined as finding the profile Ω(s) of the input speed of the VFD, which leads to low power consumption P(Ω) of the engine, but with the satisfaction of constraints (a-C), together with the following additional constraint:
where V0represents the desired flow rate.
Power consumption P(Ω) can be measured directly using a VFD or may be calculated as the work done by the engine per unit time, so you need to minimize the following functionality:
where w(Ω) represents the work done with the help of positive torque of the engine during the same turn.
where: W(Ω,t) represents the angular velocity of the engine as a function of time;
M+(Ω,t) is a positive motor torque, which is defined as:
To solve the above optimization problems, i.e. problems (I) with the constraints is s (a-C) or problem (II) with constraints (A-D), you must obtain the following information in response to any input velocity Ω(s):
- the value of the flow rate V(Ω) or, equivalently, the length of the Up(Ω) stroke of the plunger and the period T(Ω) stroke;
- the distribution of σ(Ω,x,t) voltages for all columns rod x ε(0,L) and period t ε (0, T0) moves, and on this basis to obtain σmin(Ω,x) and σmax(Ω,x)that are defined in the condition (A);
- torque M (Ω,s) of the engine for the entire stroke length s ε (0,s0), and on this basis to obtain Mmin(Ω) and Mmax(Ω, which is defined in the condition ();
- power consumption P(Ω) of the primary engine, or, equivalently, the work W(Ω) or the period T(Ω) of turn.
The information for a given input speed Ω(s) can be obtained in various ways, ranging from a fully experimental to theoretical. As a rule, experimental methods are more accurate but require more effort with the adjustment means of measurement, testing and data collection for each input function Ω(s). Usually the most effective approach is a combination of experimental and theoretical methods.
The following is a brief description of some possible approaches:
The flow rate can be measured directly by experiment if you have the necessary equipment or can be caters is based on stroke and stroke period, which can be measured or calculated.
The period T(Ω) stroke for a given input speed Ω(s) can be measured directly at the input of the VFD real system pump/well or can be calculated theoretically assuming that the motor speed is identical to the input speed of the VFD with a constant input delay.
The plunger stroke can be measured experimentally, such as the installation of accelerometers on the plunger or can be calculated in two ways: 1) using a mathematical model of the movement of the plunger based on the measurement surface dynamogeny, i.e. movement and the efforts of the polished rod; and 2) by applying a theoretical method, using the calculated motion of the polished rod as a function of motor speed and using predictive analysis to find the response of the plunger to this movement.
The voltage along the column rod can be measured experimentally, for example, through the installation of strain gages in various places (although this is rather impractical), or can be calculated in two ways: 1) using a mathematical model of movement of the sucker rods string and attached forces based on the measurements of surface dynamogeny; and 2) by applying a theoretical method, with COI is whether the calculation of the movement of the polished rod as a function of motor speed and using predictive analysis, to find the stress distribution in the string of pump rods.
- Motor torque can be measured directly using the output of the VFD when the application desired input speed of the VFD system pump/well, or can be calculated using the equations of dynamic equilibrium of the surface unit, on the basis of theoretically calculated force in the polished rod, obtained from the dynamic model of the sucker rods string.
- Power consumption of the motor can be measured directly using the output of the VFD when the application desired input speed of the VFD system pump/well or can be calculated theoretically on the basis of work performed theoretically calculated torque, when imposed angular velocity of the engine.
Problems (I) and (II) optimization are very similar from a mathematical point of view and can be solved using the same methods. Therefore, a possible solution will be presented here only for the case (I). Solution (I) can be obtained (but without limitation) by using the following iterative approach, which was chosen taking into account the highly nonlinear nature of this problem.
The function Ω [p](s)describing any valid input speed of the VFD, which meets the condition (C), can be represented as the following Fourier series:
p=[p1,...,[p2N+1]=[β,γ1,...,γN,λ1,...,λN] is a vector of variables/ parameters optimization, is a typical constant working speed of the primary engine for specific wells and pumping unit.
N is a selected number of members in the Fourier series, usually not more than 4.
The task of optimization is to find the vector p of parameters for which the function Ω[p](s) maximizes the flow rate V(Ω), defined by expression (1), however, when conditions (a) and (B). Due to the nonlinear nature of this problem, the optimal solution can be found using an iterative method, starting from some initial set of parameters, usually chosen on the basis of their own experience. The closer to optimal the selected initial value, the faster can be achieved convergence to the optimal point. Typically use the following initial parameters:
λ1∈(-0.1, 0.1), depending on the material of the pump rod (glass or steel)
λi=0 for i>1
γ2=0.2, γi=0 (i=1 or i>2)
Now any operating parameters of the pumping system, managed directly or indirectly through the input speed Ω[p](s) VD, such as the flow rate V(Ω[p]), the torque M(Ω[p],s) and primary motor and voltage σ(Ω[R],x,t) in the string of pump rods, can be treated as functions of the vector R parameter:
σ[p],x,t)=σ(Ω[p],x,t) xε(0,L); tε(0,T).
By using one of these earlier methods to determine the values of all of the above functions at the starting point R=R0. You can then find a vector δ=[δ1,..., δ2N+1]for which the function σ[p0+δ] and M[p0+δ] satisfy the constraints (a) and (b), and for which the maximum of the function V[p0+δ] is in the neighborhood of p0
Functions V, M and σ parameters p are available in analytical form and depend on these parameters is highly nonlinear way. Their definition may even include physical testing. However, these functions can be approximated in the point R0linear functions δ using the Taylor series of the first order:
where the partial derivatives of the functions V, M and σ are calculated from finite differences for each i (i=1,...,2N+1) using the following formulas:
Various input parameters R=R0+Δpi(i=1,...2N+1) create variations in the speed of the engine, which can lead to small changes of the period T[p0+Δpi] move relative to R=R0. To ensure the possibility of imposing stresses σ (Ω[p],x,t) along the column rod for the same time during cycles with different periods, the time t can be scaled by a constant reference period T[p0], for example, the time t defined for period T[p0+Δpi], can be converted at time ti+for period T[p0].
In calculation of partial derivatives with finite differences, values Δpi should be chosen so as to ensure rapid convergence to the optimal solution of nonlinear problems. In order to control the error, which is obtained by approximation of nonlinear problems, the following additional restrictions imposed on the values of δpi
where θ is initially set equal to 1, but which should be reduced if you encounter difficulties with achieving convergence.
As can be understood from a consideration of the equations (6A-C), highly nonlinear problem (I) optimization boils down to the SKU of the minimum of a linear function V[p 0+δp] vector δ object with linear constraints (A), (b) and (E). Search the specified minimum may be carried out by specialists in the field using any of the known methods of linear programming.
After calculation of the optimal vector δ0for approximation problems of optimization, you can repeat the whole process, starting from a new point p1=p0+δ0that will be closer to the optimal solution of the original nonlinear problem than the period p0. This process can be repeated until, until you change the optimal vector p from the previous iteration, that is,
where ε represents a selected threshold for convergence criteria.
The most effective is the implementation of the optimization process in two stages. At the first stage are theoretical optimal solution based on predictive analysis, without testing on a real system pump/borehole to determine its response to various input speed (the original can be carried out only basic tests to determine system parameters). In the second stage, find the actual optimal solution, based on theoretical solution and using the responses of the real system at different input speed required for the algorithm the optimization. The transition between these two stages require changing the optimization settings of the motor speed to the input speed of the VFD. This requires a conversion of the parameters of the Fourier series to reflect the time delay between the input VFD speed and engine response, which is, however, fairly straightforward. The use of this approach with two stages allows you to limit the physical testing of the system by only one iteration (one of them).
Specialists in this field it is well known that for the calculation of the optimized speed of the primary engine should evaluate the characteristics of the pumping system based on the exact response of the system. The exact position of the polished rod predominantly determined through the use of an optical position sensor, contactless rotary magneto-resistive position sensor or other similar high precision rotary position sensor mounted on the Central bearing of the pumping unit or on the crank. In accordance with the present invention mainly continuously monitor and transmit all the modes work well on a Central computer, which calculates the optimal speed of the primary engine and the relevant working couples who TRS primary engine. New parameters are then passed to the local controller of the hole by means of data transmission by wire or by radio transmissions. Closed loop feedback between the local controller and the Central computer allows you to adjust the mathematical model and to adjust its parameters to achieve the most accurate display of the physical condition of the downhole and surface components, and also allows you to identify trends and changes modes. The controller also allows you to detect any dangerous conditions outside the specified range of load factors for any component of the pumping system. Thus, the values of angular velocity (rpm), speed and torque for each part of the cycle is based on tracking the optimal speed of the primary engine to maximize the full volume of production, but while maintaining safe operating parameters.
The surface equipment and the primary engine
Surface equipment used to produce oscillating movement of the pump rod and pump at the bottom of the well. The pumping unit typically contains:
- rocker with a cylinder, of a stabilizer;
- crank counterbalance;
- gearbox and engine.
By optimizing the speed of the primary engine to newleaseduration to transmit the movement of the polished rod to the string of sucker rods and the pump, the efficiency of the pumping unit can be increased, power consumption can be reduced, the tension in the string of pump rods can be reduced and balanced pumping unit can be improved.
When variable speed motor all of these elements rotate and move with variable speed and acceleration. Actions accelerate lead to the emergence of dynamic forces and moments that affect the characteristics of the pumping unit as a whole. For example, the acceleration acts on the torque gearbox, power consumption of the motor, the strength of the balancer and the wear of the gearbox, etc. Proper loading of the gearbox is of particular importance, as underloaded unit works with low mechanical efficiency. Overloaded the unit can be damaged easily and then will require large repairs. The calculated values of dynamic torque and forecasting/optimization of the characteristics of the pumping unit is only possible when you know the correct data on the weights and moments of inertia of the moving and rotating elements of the pumping unit. This data is required to assess the characteristics previously carrying out any optimization. In accordance with the preferred option, most of the information needed to calculate torque, load balancing is OK, and the like, automatically.
Characteristics of the pump rod and pump
Sucker rod is a long, flexible rod, which contains several sections with different cross sections. This rod is attached at one end to the walking beam of the pumping unit by means of a head balancer and the polished rod and to the submersible pump at the other end. It is necessary to maintain voltage and the load factor of safety rod within the recommended range, the corresponding fatigue strength of the material rod. Evaluation of stresses in the rod is made with the use of a mathematical model of the column rod, on the basis of one of the following provisions:
- use loads in the polished rod, measured on the surface (diagnostic analysis);
- evaluation of the forces acting on the plunger at the bottom of the well (predictive analysis);
Calculation of stresses in the string of sucker rods connected with complex mechanical and mathematical problems caused by the fact that:
- flexible column rod is very long and has a non-linear movement and possibly cracked;
the rod has a complex three-dimensional geometry;
- rod moves inside the tubing string not only along it, but also in the lateral direction;
the rod is in contact with the lifting columns is th, which unpredictably shifted along the rod; and
- rod immersed in a viscous fluid.
To create a mathematical model of the sucker rods string requires detailed and accurate information on many parameters, which enables us to accurately determine the load and the voltage in the pump rod. Therefore, it is necessary first to develop an appropriate mathematical model of the dynamics of the sucker rods string with the correct parameter values, and then to find a solution using well-known and effective mathematical methods. Additional information needed for the optimization process are using the measurements in the borehole. Instantaneous flow measurements from wells and production wells, along with the tools of pattern recognition, which is used to identify downhole characteristics, give a large amount of useful information. System software allows to reproduce the dynamic modes of the system using measurements of surface dynamogeny and using measurements of the production of the well. The software allows you to choose the best modes of pumping for reducing stresses in the rod, and to determine the velocity profile of the engine in a cycle of pumping in accordance with the desired movement of the pump. About the testing software allows you to choose the optimal value of the speed of pumping and to determine the optimal speed of the primary engine. All these changes can be made at minimal cost, this can be achieved a reduction in operating costs, as it does not require any physical changes to the configuration of the surface of the block, columns rod or pump (assuming that the block contains all the elements required in accordance with the present invention).
Despite the fact that now for specialists in this field become apparent various means and ways to control the speed of the primary engine and, consequently, movement of the polished rod, some applications are particularly useful in the field of production fluid from the well.
The use of the proposed means and methods, for example, for performance evaluation and optimal operating parameters of the reciprocating pump located below the level of the fluid in the borehole and connected to a reciprocating mechanism on the surface through a system of flexible rods may be made by:
a) calculation of the performance of flexible pump rod and pump using any suitable digital method, known to specialists in this area to accurately determine and calculate all of the variables in the mechanical system of rods, submersible pump and surface the local unit, when the dynamic change of the velocities and accelerations of all components that have mass and inertia in the system that modifies mechanical and viscous friction, and the like; and
b) calculate the optimized performance and optimized working surface of the block, such as (but without limitation) the machine-rocking with Centerpoint trim, block long course or unit with hydraulic control, with a primary engine, working with an intentionally given constant speed of rotation in any single cycle of the reciprocating motion, in order to obtain the desired optimized operation of the polished rod, the sucker rods string and submersible pump.
Offered here is the technical means and methods also allow to improve the performance of the pumping system pumping with the use of sucker rods due to the control operation of the pumping system, which contains:
a) a variable speed drive and the primary motor brake or regenerative unit or without them, to control the reciprocating movement of the surface unit in accordance with the optimized parameters for each single cycle of movement, with nonconstant speed, acceleration and torque;
b) a local control unit, which can be the t be a programmable controller or digital signal processor-based computer operating system with single - or multi-tasking mode, with separate or combined as part of a variable speed drive to enter the desirable characteristics of the reciprocating motion of the surface of the block in the variable-speed drive for a minimum of 24 times during each single cycle of the reciprocating motion;
c) a local unit of data collection, which may be a programmable controller or digital signal processor-based computer with the operating system with single - or multi-tasking mode, with separate or combined as part of a variable speed drive to record the parameters of time, angular velocity, acceleration and torque of the variable speed drive, the parameters of the load and position of the polished rod, the pressure in the tubing string and casing pressure, and possible consumption during each single cycle of the reciprocating motion;
d) a remote computing station with a feedback circuit closed through the communication channel, to optimize local control unit and to control them. Remote computing station may be located at a great distance or nearby and can manage one local control unit or any of them.
This system is discussed further in more details what.
Described here is the technical means and methods allow you to automatically change the operating parameters of the pumping unit with pump rods in response to changing modes in the borehole or surface components, due to the following operations:
a) the creation of a permanent real-time communication with the local controller unit pumping on the Internet, and this connection may be implemented using a wired connection, radio or satellite communication;
b) calculation of the optimized operating parameters using any suitable digital method, well-known experts in this field, and the introduction of them by programming tool alarm or shutdown feature local control unit for detecting, during a single stroke of the operating modes of the pumping unit exceeds the limit value;
c) the introduction of corrective actions by programming in the local control unit, and the specified corrective action can be the alarm, instant off, slow off during one cycle or switching to a predefined emergency mode;
d) establishing communication with a remote computing station, immediately or within a specified time period;
e) introduction of standard software korrektiruyushiye to a remote computing station, to automatically analyze a new mode of pumping unit, which has a deviation from the previously calculated best operating modes;
f) automatically or by the operator loading the new operating parameters in the local control unit to adjust the characteristics of the pump in the new conditions;
g) automatically or by the operator loading the new operating parameters in the local control unit to change the speed distribution of chemicals in response to increased friction in the borehole due to the deposition of various materials.
As a final example of the use of the present invention can indicate that the proposed technical means and methods can be used to automatically prevent or avoid formation of gas pockets in the pump due to the following operations:
a) the gas detection tube due to the (measurement) forces acting on the plunger in its course down;
b) calculation of pressure initial boiling point during the flow of fluid which may be oil, water or without it, through the narrowest cross-section of the suction valve downhole pump;
c) the calculation of the optimal movement of the plunger in order to minimize the velocity of the piston during the stroke down, in order to minimize the velocity of the fluid and the pressure drop in the fluid at vsasyvauschie what about the valve, in order to keep the pressure above the pressure of the beginning of the boil;
d) the speed and acceleration of the primary engine in the range estimated optimum motion to minimize or eliminate the probability of formation of the gas tubes in the exact movement of the polished rod.
Were are only some examples of how the present invention can be used in a number of practical working situations in the extraction of fluid from the well, using the here described methods and systems.
We now turn to a consideration of the drawings, which shows the approximate variant of the system in accordance with the present invention.
Refer first to a consideration of figure 1, which shows a typical machine-rocking with Centerpoint trim for oil wells that contain many moving parts that create significant inertial forces during acceleration or deceleration in excess of a typical static power. The head 1 of the walking beam pumping unit connects the rod system 9 and the pump 10 with the rocker 2 using jumper cables and hook rod. The connecting rod 3 connects the collector head 2 with the crank 5 with counterweights 6. The crank 5 is connected with the shaft gear 4, which is driven through a system of belts from the primary motor 7.
Rod system 9 and the pump 0 is exposed to mechanical friction (due to the interaction of the pump 10 with the pump cylinder and the rod 9 with the Elevator column), fluid friction (due to the movement of the rod 9 in the viscous fluid and the motion of viscous fluid in the tubing string and through the valves of the pump 10) and efforts due to the hydrostatic pressure and the inertia of the fluid. Rod system 9 is a flexible connection between the surface components and submersible pump 10. On its characteristics of flexibility strongly influenced by the dimensions and material properties of each boom section and the depth of the well. Due to the flexibility of the rod 9 and the cyclic changes of the force, speed and acceleration of the polished rod, sucker rod 9 oscillates in the longitudinal and transverse directions in the well.
Four measurement tools or sensor installed on the pumping unit. The measurement tool or the load sensor 11, which may be a load cell, connected to the polished rod and produces an output signal proportional to the load. Having a high accuracy position sensor, which may be an optical sensor 8 position is on the center bearing and fixed on the front of the balancer. It allows you to determine the exact position of the balance weight 2, regardless of speed or acceleration. Two pressure sensor installed on the wellhead, namely the pressure sensor 12 in the tubing string and the sensor 13 of the casing pressure. They allow to determine the exact pressure, which is what s proper way to evaluate the operation of the pump during each cycle.
Machine-rocking with balancing balancing is driven by means of the primary motor 7, which may be having a high efficiency motor Nema In order to create reciprocation of the polished rod in accordance with the desired motion profile. The polished rod is connected by means of various passages of the pump rod 9 with a submersible pump 10. The present invention is directed to the management of the movement of the polished rod that the submersible pump 10 performs reciprocating motion within any desired stroke length in order to maximize well production rate with limited fatigue loading pump rod 9. In addition, you can control the speed submersible pump 10 and its operation to prevent excessive friction, education, gas tubes and other harmful modes in the well.
As shown in figure 1, the signal 17 of the regulations, the signal 18, the load signal 19, the pressure in the tubing string and the signal 20 of the casing pressure received in the local control block 21, which converts, processes and stores this information in a digital memory, which can be (but without limitation) hard drive or solid state memory modules. Additional signals 16 speed and torque come in block 21 of the control from the controller 1 a typical variable-speed drive, which controls the operation of the primary motor 7 due to a change in voltage, current and frequency of the power supplied to the primary motor 7. Primary motor 7 and the controller 14 of the variable speed drive are connected by signal 15. The controller 14 of the variable speed drive can contain dynamic braking resistor, and various other components and may be a controller of any suitable type commercially available. Local control block 21 transmits the collected information through the communication unit to the remote computing station 23, which may be having more computing power desktop computer with multiprogramming (with multi-tasking mode) operating system. Can be used various means 22 communications, including fixed-line, Internet, radio, telephone network, or satellite communications. The channel creates a closed feedback loop between the local unit 21 controls and remote computing station 23.
The modes in the borehole and at the surface analyze and optimize using the software on the basis of the process, the operation of which is shown in figa and 2b, and which includes as predictive analysis, and diagnostic analysis. Operations 30-44 this process shows the and figa, and subsequent operations 46-60 this process is shown in fig.2b.
Figure 3-6 shows performance data for a well depth 9,057 feet, which was one of the four test wells for evaluation of the present invention. Having a regular geometry of the pumping unit (640-365-168) was connected with the sucker-rod pump with a diameter of 1.75 inches, with thick walls, using columns of steel sucker rods, collected from five sections of different diameters. Data were obtained for a typical constant speed mode for optimized mode using the primary engine with optimal variable angular velocity. The stroke length of a submersible pump controlled by measuring the volume of production during the period of 24 hours. Data measuring the level of fluid were used to check the calculated forces acting on the plunger. Produced long-term data collection in the course of time more than six months to confirm the effectiveness and further development of technical tools, optimization techniques and software.
Figure 3 shows a graph of the measured speed of the primary engine for two cases: constant speed, providing the pumping speed 6.3 SPM (strokes a minute) at a constant speed of the crank; and optimized variable speed Prime mover, providing what I pumping speed 7.6 SPM.
Figure 4 shows a graph of the measured linear speed of the polished rod before and after optimization. It is clear that the optimal speed is not constant at all sections of a course that was required in accordance with the prior art, and is significantly different from the typical speed of the polished rod at a constant angular speed of the primary engine.
Figure 5 shows a graph of measured efforts of the polished rod and the estimated effort of the plunger relative movement during operation of the pump at a constant speed primary motor and optimized optimal variable speed Prime mover.
Using the software was calculated and the selected constant angular velocity corresponding to 6.3 SPM, creating the stroke length of the pump 114 inches, which was confirmed by actual measurement of the flow of fluid from the well to the surface. Through the use of optimized variable speed primary motor obtained by calculation using the software, the period of the course was reduced to match 7.6 SPM, stroke length of the pump was increased to 143 inches, which was confirmed by actual measurement of the flow of fluid from the well to the surface. Received a sharp increase in production partially explained as the increase in the stroke length of the pump (25%), and reduction of the time course (20%). When this did not observe any increase of the forces acting on any component equipment of the well, and through the use of inertia of rotating loads, energy consumption was reduced by 27%. For professionals in this field is obvious that for any typical wells, by increasing the constant speed of the Prime mover to increase at a constant speed pump from 6.3 SPM to 7.6 SPM, can be achieved with a much smaller increase in the stroke length of the pump, but with a considerable increase in consumption of energy and forces acting on the system components.
Figure 6 shows a graph of the measured torque of the gearbox before and after optimization. Since the torque of the gearbox is well below the maximum allowable torque, the optimization problem is to minimize the regenerative torque in order to minimize its negative impact on the service life of the gearbox.
Calculate the optimal velocity, acceleration and torque of the primary engine, and the calculation of the safe operating mode, and all these data are transmitted to the local control unit 21. The response unit after at least one full cycle of operation is then passed through the communication unit in the remote computing station 23 is analyze it. If the optimized parameters (such as the estimated length of stroke of the pump running time, power consumption, levels of stress and tension in the rods and in the surface components, the velocity of the fluid at the suction valve, the maximum and minimum motor torque, etc. are satisfactory, the calculation is no longer made, if only in the following will not be detected deterioration of the production of the well. Periodically at predetermined time intervals, the remote unit 23 or the local unit 21 checks the state of the pumping unit. The local unit 21 controls allows you to create the actuator 14 with adjustable speed, with the estimated angular velocity (Rev/min) and acceleration of at least 24 degrees during each cycle, and the unit 21 controls the operation of the pumping unit, providing a safe operating parameters, such as maximum and minimum polished rod load, motor torque, the torque of the gearbox, the movement of the polished rod, the pressure in the tubing string, the pressure in the casing string and the running time.
If any of the safe operating parameters outside the specified values, the local unit 21 starts corrective action, such as slowing down or disabling unit, this creates an emergency message that comes remotely calculate the additional station 23 through the system with closed loop feedback. The last operating modes arrive at the remote computing station 23, a calculation is made of the new optimized operating parameters, which are then transmitted to the local unit 21.
Despite what has been described the preferred embodiment of the invention, it is clear that it specialists in this field can be amended and supplemented, which is not beyond the scope of the claims.
1. The way to determine the optimum variable angular velocity Q of the primary motor of the pumping unit, equipped with a pump rod connected to the submersible pump for pumping pump fluid from the well, and specified the optimal angular velocity varies during a single pumping cycle so that the well productivity is maximised while maintaining the specified maximum allowable stresses in the pump rod and the maximum permissible motor speed, torque and energy consumption, and this method includes the following operations:
(i) use of a finite number of parameters p to display the angular velocity Ω[p] of the engine as a function of one variable selected from the group of variables, which includes the position s of the polished rod, the position of the crank (only for pumping units with balancing balancing is m) or the time t, accordingly, Ω[p](s), Ω[p](a) or Ω[p(t) for every single full cycle of pumping;
(ii) the creation of a full dynamic model of the pumping system, including surface equipment, including rocking simplified type with engine and polished rod and downhole equipment, including pumping rod with a submersible pump, for calculating the torque of the engine, the voltage at the specified pump rod and the output flow rate of the well, in response to a given angular velocity Ω[p] of the engine, and the output flow rate V(Ω) is well defined as the volume Vol(Ω), pumped by the pump during the period T(Q) of one cycle, that is, V(Ω)=Vol(Ω)/T(Ω); and
(iii) determination of the parameters p using a mathematical algorithm for solving nonlinear optimization problems, in which the angular velocity Ω[p] engine maximizes the flow rate V(Ω) wells, while satisfying the following constraints:
(a) the minimum and maximum voltage pump rod within the specified full of single cycle obtained due to the imposed speed Ω of the engine, do not exceed specified thresholds;
(b) motor torque required to create a speed Ω of the engine exceeds the set limit value for the specified loop;
(c) the angular speed Ω of the engine is the same is the beginning and end of the pumping cycle;
(d) the angular velocity Ω of the motor does not exceed the set limit value during the pumping cycle; and
(e) the energy consumption of the engine divided by the volume of pumped fluid, calculated using the torque of the engine and the angular velocity during the pumping cycle, does not exceed the set limit value.
2. The method according to claim 1, in which the angular velocity Ω of the motor show in the form of Fourier series, and the variable angular velocity is determined from the optimal set of Fourier coefficients.
3. The method according to claim 1, which additionally includes the following operations:
(i) displaying the angular speed Ω of the engine in the form of a Fourier series for the position of the polished rod s to satisfy constraint 1.(iii)(c):
where the vector p=[β,γ1,...,γN,λ1,...λN] contains the Fourier coefficients, Ω0is a typical working at a constant speed, this rocking simplified type,
a sodenotes twice the length of stroke of the polished rod;
(ii) creating a mathematical model for calculation of displacements, forces and stresses in the pump rod and the polished rod during the pumping cycle, which will occur when the movement of the polished rod, caused by the applied predetermined variable angular velocity Ω of the motor;
(iii) creating a mathematical model for calculating the torque of the engine that you want to create a variable angular speed Ω of the engine, and in this model use the power of the polished rod, calculated in model 3.(ii), and the force of gravity and inertial forces acting on all components rocking simplified, which are determined by its geometry and mass distribution;
(iv) creating a mathematical formula to calculate the energy consumption of the motor based on the torque and the angular speed of the motor;
(v) creating a mathematical formula to calculate the output flow rate V(Ω) wells on the basis of the ratio of the length of the stroke of a submersible pump to stroke period T(Ω);
(vi) creating a mathematical algorithm to determine the optimal distribution of instantaneous angular speed of the engine during each single cycle of pumping by finding an optimal set p=[β,γ1,...,γN,λ1,...λN] of the Fourier coefficients, so that the volume V(Ω [p]) pumping becomes maximum, while satisfying constraints l.(iii)(a)-(e); and the specified algorithm contains the following:
(a) the choice of initial vector of p0the Fourier coefficients and vectors Δitheir increments for each parameter i=1,...2N+1;
(b) the use of predictive analysis, which is cancel in itself a mathematical model, described in (ii)-(v)to calculate the flow rate V[p], the energy consumed is P[R], torque M[p](s) engine and distribution σ[p](x,t) stresses in the pump rod during the entire cycle, in response to the angular velocity Ω [p] engine defined from the above equation, 'Oh' in the following points: R=R0and p=p0+Δpi (i=1,...2N+1);
(c) calculation of partial derivatives of the function V[p], M[p](s), σ[p](x,1) and P[p] with respect to the parameters pi(i=1,...2N+1), using the method of finite differences and incremental values calculated above in 3.(vi)(b);
(d) using the Taylor expansion of the first order and partial derivatives calculated above in(C)to obtain the linearized function V[p], M[p](s)), σ[p](x,t) and T[p] with respect to small changes δpi parameters pi;
(e) the linearization of the problem of optimization with respect to δpi through the use of these linear functions of the 3.(vi)(d) subject to the constraints given in claim 1.(iii)(a)-(e)and the function V[p] optimization;
(f) using the linear programming method for finding δpi, which is the solution of linear optimization problems defined in 3.(vi)(e), namely that allows you to maximize well production rate, however, satises the linear constraints relative to the torque and speed of the engine, the stresses in the pump rod and the power consumption;
(g) replacing the initial what about the vector R 0p0+δ and repeat operations 3.(vi)(b)-(f) until such time as δ will not be less than the selected limit value;
and (h) converting functions Ω[p](s) in function of time or position of the crank.
4. The method according to claim 1, in which the optimal variable speed primary motor is determined so that it becomes the minimum one of the following performance indicators: energy consumption by primary engine on the volume rolled back fluid, the maximum torque of the engine or the voltage range in all segments of the pump rod, while maintaining these indicators within the specified limits, and pumped by pump production volume exceeds a specified value.
5. The way to determine the optimum speed U of the polished rod connected by means of a pump rod with a submersible pump for pumping fluid from a well, and the specified optimum speed varies during the period of each single pumping cycle so that the flow rate becomes maximum, while maintaining the limit speed of the polished rod, the stresses in the pump rod and the energy required to create the specified speed of the polished rod, which includes the following operations:
(i) use of a finite number of parameters p to display the speed of the polished rod U[p] as fu the functions U[p](s) position of the polished rod s or a function U[p](f) time t for a full pumping cycle;
(ii) the creation of a dynamic model of downhole equipment (pump rod with a submersible pump) to calculate stresses in the specified pumping the rod and flow rate in response to a predetermined speed of the polished rod U[p], and the specified flow rate V(U) is well defined as the volume Vol(U), pumped in period T(U) of one cycle, that is, V(U)=Vol(Ω)/T(Ω); and
(iii) determination of the parameters p using a mathematical algorithm for solving nonlinear optimization problems, in which the velocity U[p] the polished rod during this cycle will be pumping to maximize the flow rate V(U) wells, however, satisfy the following restrictions:
(a) the minimum and maximum voltage pump rod within the specified full of single cycle obtained due to the imposed velocity U of the polished rod, do not exceed specified thresholds;
(b) the velocity U of the polished rod is equal to zero in the upper and the lower positions of the polished rod;
(c) the velocity U of the polished rod does not exceed the specified limit values for the full cycle of pumping;
(d) the energy required to create motion specified the polished rod during the period of one cycle of pumping divided by the volume of the evacuated fluid does not exceed the defined limit value.
6. The method according to claim 5, in which oterom to meet restrictions 5.(iii)(b) the velocity U of the polished rod is expressed as the Fourier series of regulation s of the polished rod,
defined separately for the stroke of up to s∈(0,s0/2) and turn down s∈(S0/2,S0), part of the movement (s0represents the length of the double stroke of the polished rod):
and in which the specified optimum variable speed of the polished rod during a single cycle of the pumping determine the optimal set of Fourier coefficients p=[u1U,...,uNUu1D,...,uND].
7. The method according to claim 5, in which the optimal variable speed of the polished rod determined so that the voltage range in all segments of the pump rod will be minimal, while the pumped volume and the energy required to create motion specified the polished rod during the period of one cycle T of pumping, reach pre-selected values.
8. The method according to claim 5, in which the optimal variable speed of the polished rod determined so that the ratio of the energy needed to create motion specified the polished rod during the period of one cycle of pumping, the volume of pumped fluid will be minimal, while the pumped volume and the range of voltages in all segments of the pump rod reaches the pre-selected values.
9. The way to improve the accuracy of calculating the optimal is Noah angular speed of the primary engine according to claim 1 or optimal speed of the polished rod according to claim 5,
in which the measurements obtained in real evacuation system, used to improve the system parameters in the mathematical model used in the optimization method, which includes the following operations:
(i) measuring the physical modes of the system pumping during operation, namely the measurement of the load and position of the specified polished rod, torque, engine, energy consumption, pressure in the tubing string and the casing string and the well production rate;
(ii) comparison of model results of the pumping system and the measured physical modes to verify and adjust the model parameters of the pumping system;
(iii) calculate the new optimal angular speed Ω of the engine or the new optimal speed U of the polished rod based on the model of the pumping system with the adjusted system parameters.
10. The method according to claim 5, in which the optimal variable angular speed of the primary engine of Ω calculated from the optimal velocity U of the polished rod using geometry rocking simplified type.
11. The speed regulation system and pumping system rocking simplified type, which includes:
(i) primary motor to control the movement of the rocking simplified;
(ii) a controller of a variable speed drive (VFD) for dynamic upravleniemoeda angular speed of the primary engine in full pumping cycle;
(iii) borehole pumping components containing the pump rod for transmitting movement of the rocking simplified to the submersible pump;
(iv) measurement tools for monitoring operational modes;
(v) a local control unit allowing to pass the instantaneous speed of the primary motor on the VFD and get instantaneous speed and torque of the Prime mover from the VFD, and this block contains the program that contains the model of the pumping system and the various decision tools for analysis of transmitted information, assess the characteristics of the pumping unit and the downhole components and determine the optimal speed of the primary engine according to claim 1 or 10, which are used to control the speed of the primary engine with predetermined time intervals in the full cycle of pumping.
12. The speed regulation system and pumping system rocking simplified type, which includes:
(i) primary motor to control the movement of the rocking simplified;
(ii) a controller of a variable speed drive (VFD) for dynamic control of the instantaneous angular speed of the primary engine in the full cycle of pumping;
(iii) borehole pumping components containing the pump rod for transmitting movement of the rocking simplified to the submersible pump;
(iv) measurement tools to monitor the working modes;
(v) a local control unit allowing to pass the instantaneous speed of the primary motor on the VFD and get instantaneous speed and torque of the Prime mover from the VFD;
(vi) means of transmission signal intended for transmission of information in real-time from the local control unit to the remote computing station;
(vii) with the specified remote computer station equipped with software that contains a model of the pumping system and the various decision tools for analysis of transmitted information, assess the characteristics of the pumping unit and the downhole components and determine the optimal speed of the primary engine according to claim 1 or 10, which are used to control the speed of the primary engine with predetermined time intervals in the full cycle of pumping;
(viii) means of transmission for optimal speed of the primary engine and new operating parameters from a remote computing station to the local control unit to control the speed of the primary engine.
13. The system according to claim 11 or 12, in which the optimum speed of the primary engine is applied for a given position of the polished rod.
14. The system according to claim 11 or 12, in which the optimum speed of the primary engine is applied for a given position of the crank.
15. The system is about 11. (iv) or 12. (iv)in which measurement tools used to measure the load of the polished rod, the position of the polished rod, the pressure in the tubing string and casing pressure.
16. The system according to claim 11 or 12, in which the VFD contains dynamic brake resistor or regenerative module.
17. The method according to claim 1 or 10, in which the primary motor is an electric motor or internal combustion engine, and a variable speed pumping system set with control of the instantaneous gear ratio.
18. The method according to claim 5, in which the speed of the polished rod is controlled by means of the pumping system with hydraulic control, and set new operating parameters of the pumping system by controlling the pressure and flow control system the pumping system to control the speed of the polished rod in accordance with the calculated optimum movement.
FIELD: engines and pumps.
SUBSTANCE: invention relates to oil production and can be used in reciprocation rod-type downhole pump (RDHP) using jacks as drives. In compliance with proposed method, crank rpm and rod reciprocation speed matched therewith are varied by sine law in smoothly accelerating operating stroke, whereat rod up travel reaches maximum speed with con rod in vertical position and crank at lower point. Idling is proportionally decelerated, whereat rod down travel reaches minimum speed with con rod in vertical position and crank at lower point. Con rod speed at operating stroke start and idling end is decreased by magnitude smaller than mean rod reciprocation speed. Proposed jack has cranks arranged on rims running in rolling supports (or roller bearings) fitted along perimetres of openings. The latter are arranged in vertical frames fastened on opposite side of support frame. Reduction gear and motor are arranged on frame-platform mounted on support frame to move along rocker beam direction. Reduction gear output shaft extensions support hubs in the plane of rims revolution, hubs OD being smaller than rim ID. Drive rods are attached to said hubs. Every said hub has through radial or inclined groove to accommodate roller fitted on pin pressed on the end face of appropriate rim with 90°-advance along the direction of rotation, as well as with smaller or greater advance with respect to the point of attachment to crank rim.
EFFECT: higher efficiency of oil production with no deterioration in process dynamics.
8 cl, 39 dwg
FIELD: oil industry.
SUBSTANCE: invention refers to oil industry and namely to methods of simultaneous separate operation of two beds of one and the same well. The method involves lowering and installation of a packer in the well between beds, production tubing, upper and lower pumps connected in series and arranged in the production tubing and connected with rods to a common top's drive. Pump inlets are connected to the spaces above the packer and below the packer correspondingly. The upper pump outlet is connected to the flow column, and the lower pump outlet - to the upper pump inlet. Then the drive is brought into operation and adjusted so that proportional pump capacity of the translational movement speed of rods with plungers can be changed. Pumps being installed are screw-type; production tubing before being lowered is equipped with couplings with calibrated central channels arranged below the pump shells fixed on the production tubing. Upper coupling is arranged within the channel connected to the space above the packer. Pump screws are equipped with upper and lower plungers, the upper one of which is through-type for longitudinal liquid flow. Diametres of plungers and screws are decreased downwards in order to pass through the shells and couplings which are not appropriate to them when being lowered. The stock is geared with the top's drive as well. Translational movement is performed in pulse mode; upwards from medium operating position for lower piston to interact with lower seat and for lower screw to come out of the shell upwards thus cutting off the space below the packer and performing the production only from upper bed, and downwards - for upper piston to interact with upper seat thus cutting off communication channels and the space above the packer and for upper screw to come out of the shell downwards and performing the production from lower bed.
EFFECT: method allows separate investigation of properties of beds and their production by consequent cutting off beds and the pumps corresponding to them, allows working with well production containing a great number of mechanical particles because only screw pumps are used for lifting the well production, as well as continuing production without replacing a differential pump and at changing the bed productivity ratio in the course of time.
2 dwg, 2 cl
FIELD: engines and pumps.
SUBSTANCE: invention relates to oil production. Proposed drive comprises drive link shaft, drum fitted on support, circular housing consisting of base and cover with branch pipe communicating with pump-compressor pipe. Driving link shaft extension has coaxial gear with cylindrical ledge on free end face. Ledge diametre equals that of gear pitch line. There is lengthwise slot on the end face cylindrical surface. Gear wheel seats parallel to driving link shaft. Toothed concave and convex rims are arranged inside the housing. Coaxial barrels are arranged on faces of aforesaid rims. Two or more brackets are rigidly attached to the flat surface of base, the said brackets featuring arc-like concave stop. One end of concave stop is arranged above free end of cylindrical stop. Similar brackets support another arc-like convex stop. One end of convex stop is arranged above free end face of driving link shaft cylindrical ledge. Arc-like stop is arranged coaxially with latter and on brackets. There is a plate with longitudinal slot arranged between arc-like stops and housing cover, and rigidly attached to adjacent cheek of the drum. Slot outer surface width is smaller than slot bottom width. Additional flexible element is wound up on the drum. Additional hole with vertical branch pipe is arranged on the housing cover, in symmetry with the hole with flexible element. The said vertical branch pipe is tightly jointed to vertical cylinder with counterweight. The latter is jointed to second end of additional flexible element. There are some other versions of drive design.
EFFECT: higher drive efficiency.
11 cl, 16 dwg
FIELD: engines and pumps.
SUBSTANCE: invention is related to oil production industry and may be used for operation of production wells, including the ones with highly viscous produce, and also in wells of small diametre. Bottomhole pump set includes sucker-rod pump comprising cylinder, receiving valve, plunger with controlled injection valve, which is connected to string of pump rods with positioners, packer and relief device. Downstream relief device hollow tailpiece is arranged, which consists of upper and lower parts. Additional relief device is located in tailpiece. Packer is arranged in the form of self-sealing collars with distance between neighboring self-sealing collars that exceeds distance between ends of pipes in coupler joints of flow string, and support. Downstream packer and upstream support tailpiece is equipped with side holes. Additional relief device is arranged in the form of cylinder connected to lower part of tailpiece, with side channels that communicate to internal cavity of tailpiece and hollow piston connected to upper part of tailpiece, with the possibility of limited axial displacement downwards relative to cylinder with tight overlapping of connection between side channels of cylinder and internal cavity of tailpiece.
EFFECT: provides for considerable reduction of laboriousness of installation -dismantling and makes it possible to reduce time required for set lowering-lifting in well, and also to expand field of its application due to possibility to use it in wells of small diametre.
SUBSTANCE: installation consists of the first and the second cylinders. The first cylinder is equipped with a side valve with a filter and from below it is connected with a packer, which in its turn is connected with the second cylinder equipped with a side valve with a filter and a side opening. The second cylinder is connected to an adaptor equipped with a valve with a filter and connected to a polished tail, which is pressure tight installed in a polished cylinder of the packer-cut-off plate. Inside the first and the second cylinders there are installed plungers with valves, rigidly connected between them with a rod equipped with channels for produced liquid flow. The plungers are connected with a column of rods. The first cylinder is connected with a flow string.
EFFECT: there is facilitated working capacity at any values of pressure of operated reservoirs, also efficiency of pump in accordance with reservoir yields and possibility to operation of only one reservoir at complete isolation of another.
FIELD: mechanics, oil and gas industry.
SUBSTANCE: unit is intended for using as deep well pump for oil production from oil wells. The unit consists of a platform, pedestal with gearbox and rack being installed on it, electric motor coupled with gearbox through multiple V-belt drive. Differential crank converting mechanism is installed on the gearbox output shaft. The above mentioned converting mechanism contains two cranks interrelated through planetary gear. The central crank is rigidly installed on the gearbox output shaft. Driving crank with tension pulley is mounted on the central crank output shaft. Polished rod carrier bar is installed at the other side of gear box. The rack is installed on pedestal between polished rod carrier bar and tension pulley of driving crank. The oscillating equal-arm rocker is movably mounted on the rack and immovable heads are rigidly fixed to the rocker ends. From the side of converting mechanism cranks, the rocker head is connected with tension pulley of driving crank, while the other rocker head is coupled with polished rod carrier bar from the side of the above bar. The rack and rocker are implemented so that the rocker can rotate around its axis. The rocker head edges are in vertical plane, which is at some distance away from the wellhead. It is provided by the invention that balanced pumping unit design is implemented so as rack with rocker and converting crank mechanism being placed at one side of gearbox. Comfortable conditions for drive repair operations.
EFFECT: linear reciprocal motion of tension pulley is ensured on driving crank.
3 dwg, 4 cl
FIELD: engines and pumps.
SUBSTANCE: invention relates to oil production, namely to pumping units to force extracted local water into petroliferous stratum to keep up formation pressure therein. The proposed unit comprises a casing string coupled with a deep-well pump incorporating a cylinder with suction valve and a plunger with pressure valve lowered into operating well string with perforated parts opposite the petroliferous stratum and water producing formation. The wall packer is fitted on the pumping pipe string end and closes the hole clearance above the water producing formation. The tubular pump is arranged in the pumping pipe string above its end. The cylinder is furnished with lateral holes arranged at such a level that, with the plunger in its BDC, the said holes are open and communicate hydraulically the pumping pipe string inner space with the wall hole clearance above the packer, and, with the plunger in TDC, the said holes are blocked.
EFFECT: possibility to use whatever-type pump, to adjust forcing water a integral system of keeping up formation pressure and to exploit petroliferous stratum free areas with weakly-permeable reservoirs thanks to independent pumping in.
FIELD: engines and pumps.
SUBSTANCE: invention is related to oil industry and may find application in oil production from two beds of single well. The plant includes sucker-rod pump with plunger, cylinder, suction and pressure valves. Cylinder is equipped with side valve with filter. Auxiliary cylinder with side holes is fixed in cylinder, as well as jacket with provision of annular space between auxiliary cylinder and annular space jacket. Lower end of cylinder is plugged with plug. Suction valve, filter and tail with packer at the end are fixed on jacket. Plunger is arranged as combined, consisting of upper and lower plungers connected with stem with valves, with installation of upper plunger inside cylinder and lower plunger inside auxiliary cylinder. Lower plunger and stem have channel for communication of space above and under lower plunger. Upper plunger and stem have channel for space connection under upper plunger with inlet to upper plunger valve.
EFFECT: provision of serviceability at any values of pressure in operated beds and possibility to operate only one of beds.
FIELD: engines and pumps.
SUBSTANCE: device is designed for application in the field of oil production by well pumps. Drive comprises guide link shaft having gear and drum joined to electric motor, annular body installed on support and having base and cover with nozzle joined to pump-compressor pipe. Cylindrical protrusion is arranged on free end of guide link shaft gear. Long slot is arranged on cylindrical surface of cylindrical protrusion at the end. Gear wheel is installed parallel to gear and at the same distance from base axis. It is arranged with dimensions and cylindrical protrusion similar to dimensions and cylindrical protrusion of gear. Concave gear ring is installed inside body, and convex gear ring is installed on cover. Teeth of convex and concave gear rings are engaged with gear and gear wheel teeth. Coaxial cartridges are arranged on ends of convex and concave gear rings. At least two brackets are rigidly fixed and installed on internal flat surface of base perpendicular to this surface. Arc-shaped concave thrust is fixed at free ends of brackets, at that it is arranged with internal diametre equal to external diametre of convex gear ring cartridge external diametre, and internal diametre equal to sum of external diametre of this cartridge plus double depth of long slot. Another arc-shaped convex thrust is installed and fixed to free ends of brackets, and it has external diametre equal to internal diametre of concave gear ring cartridge. There is plank installed between arc-shaped thrusts and body cover, and it has long slot in the form of, for instance, dovetail. Drive is equipped with detector of concave and convex gear ring rotations number. Arc-shaped thrusts of gear and gear ring cylindrical protrusions are separated into two parts. Hinge axis is installed perpendicular to internal end surface of base and is installed in hole arranged in separated end of arc-shaped thrust with inclined surface. Arc-shaped thrusts with inclined surfaces are equipped with fixed joined spring-loaded levers. Free end of every lever contacts with side cylindrical surface and bottom of sprocket hub groove. Base has additional nozzle connected to counterbalance cylinder and equipped with flexible element. Flexible element is fixed by its one end to drum, and by the other - to counterbalance. Additional nozzle is connected to pump-compressor pipe of another well. In order to define place of gear ring installation, with combined apertures of long slots of cylindrical protrusion of gear and cartridge of concave gear ring, gear is turned by 180 degrees to combine apertures of slots of cylindrical protrusion of gear and cartridge of convex gear ring, gear ring convex cartridge is turned to the side of gear wheel axis installation to match line passing along axis of symmetry of cross section of long slot of convex gear ring cartridge, with middle of arc passing along circumference of concave gear ring reference diametre, selected from axis of symmetry of cross section of nearby long slot of concave gear ring cartridge to the side of gear ring installation place, and equal to length of gear reference diametre circumference, afterwards line matched with arc middle is projected to surface of base, and mark is made in the middle between circumferences of reference diametres of concave and convex gear rings on this line.
EFFECT: increased service life of well pump due to provision of electric motor rotation without stops.
6 cl, 17 dwg
FIELD: engines and pumps.
SUBSTANCE: invention relates to oil and gas production and is operated for oil extraction by well rod pumps in simultaneous operation of two formations using two plunger pumps. The proposed drive represents a pumping unit additionally incorporating props arranged on the frame to accommodate rigidly interconnected pulleys whereto one ends of cables are fastened to form, two by two, cable pairs. One pair is connected by its one end with the pumping unit suspension, the other pair is connected to the second drill rod string and the third one is coupled with the balance box arranged between the aforesaid props to be moved there between driven by rollers. To vary the drill rod string length travel, the pulley diameters are selected subject to the drill rod string length-to-length ratio.
EFFECT: higher efficiency of oil extraction, lower power consumption.
1 cl, 2 dwg
FIELD: lifting of liquids from deep wells.
SUBSTANCE: proposed unit contains submersible pump, pressure tubing string, drive shaft consisting of sucker rods whose ends are provided with slots and which are installed inside connectors. The latter are made in form of bushing with inner cylindrical ring groove in middle part and through longitudinal slots on end sections in number corresponding to number of slots on sucker rods, and blind slots located between through slots. Blind slots are made open from side pointed to cylindrical ring groove and are through in radial direction.
EFFECT: improved operation reliability, reduced service expenses, simplified design.