Method for determining profile of thermal conductivity of mine rocks in well
SUBSTANCE: according to the method, a casing string with temperature sensors attached to its outer surface is lowered to a well and cement is pumped to an annular gap between the casing string and well walls. During a cement filling and hardening process, temperature measurements are made and thermal conductivity of surrounding mine rocks of the well is determined as per the measured relationship between temperature and time.
EFFECT: possibility of simultaneous reception of information on properties of a relatively thick layer of rocks around the well and information on thermal conductivity of rocks for the whole cemented interval of depths.
3 cl, 2 dwg, 1 tbl
The invention relates to geophysical research wells and can be used to determine thermal properties of the rock formations surrounding the well.
Knowledge of thermal properties and, in particular, thermal conductivity of rocks is necessary for modeling and optimization of oil and gas, especially for optimization of thermal methods of heavy oil production. Thermal properties of rocks is usually measured in the laboratory on core samples extracted from the well. The results of measuring the heat capacity of the rock is quite applicable for modeling field temperature oil reservoir, and the results of the measurement of thermal conductivity of the core may be substantially different from thermal conductivity of the blocks of rocks in situ. This is due to:
(1) change in rock properties of the core during drilling,
(2) the difference of laboratory RT conditions from the reservoir,
(3) the influence of reservoir fluids, which do not always take into account when conducting laboratory measurements.
One of the major problems is the representative results of laboratory measurements. Usually the core recovery is significantly below 100% and laboratory studies do not give information about the properties of fractured layers and weakly consolidated rocks (where core recovery is low) that may significantly affect the value of thermal conductivity bol is the oldest blocks of rocks, used for reservoir simulation. Therefore, in addition to laboratory studies on the core for many years conducting experiments to determine thermal properties of the rocks in situ in the well, but so far not developed suitable for the practical use of the method or device.
It was proposed many different approaches to the determination of thermal conductivity of rocks in situ. For example, it was proposed to use for this purpose the recovery process of the unperturbed temperature of the array after drilling or after washing the wells (see Dehnow C. N., Deacons D. I. Thermal study wells. Moscow, HUNTINGTN, 1952, 128 S.). The disadvantage of this method is the strong dependence of the results of measurements of flow and free thermal convection of a fluid in the borehole, from the radius of the well and the position of the temperature sensor in the borehole. In addition, it is difficult to accurately simulate thermal excitation of the array during drilling or well wash that is necessary for quantitative interpretation of the measured temperature and evaluation of thermal properties of rocks.
Most of the work on determination of thermal conductivity of rocks in situ based on theory of linear heat source. A well placed long enough (3-5 m) of the heated probe and record the rate of increase of temperature of the probe, which is th depends on thermal properties of the surrounding materials (see, for example, Huenges, E., Burhardt, H., and Erbas, K., 1990. Thermal conductivity profile of the KTB pilot corehole. Scientific Drilling, 1, 224-230). The main disadvantages of this method are a great time (about 12 hours) required for the measurement of thermal properties at each site wells, the distortions associated with free thermal convection of a fluid in the borehole, and the need to supply the downhole sonde significant electrical power.
Some methods use a small heated probes, which are pressed against the borehole wall (see Kiyohashi H., Okumura K., K. Sakaguchi, and K. Matsuki, 2000). Development of direct measurement method for thermophysical properties of reservoir rocks in situ by well logging. Proceedings World Geothermal Congress 2000, Kyushu-Tohoku, Japan, May 28 - June 10, 2000. These methods allow to reduce the duration of measurements, however, they require smooth walls of the borehole, sophisticated equipment, a complex numerical model to determine thermal properties of rocks on the results of the temperature measurement probe and allow us to estimate thermal properties of only a very thin (1-3 cm) layer of rock near the borehole walls. This layer was subjected to mechanical stresses during drilling, may have induced fractures, pores in the rock filled with mud, and not a reservoir fluid, therefore, thermal properties of this layer can vary significantly from rock properties away from the well.
There are also known methods using moveable the e probes. The heat source is at the head of the probe, the temperature sensor is on the end of the probe (see, for example, U.S. patent 3,892,128). These methods allow you to quickly assess thermal properties of rocks at a considerable depth interval, however, as in the previous case, they provide information about the properties of only a very thin layer of rocks around the well.
The technical result achieved by the invention is to provide the opportunity to simultaneously obtain information about the properties of relatively thick (about 1 m) layer of rocks around the well and information about thermal conductivity of rocks for the entire case hardening depth interval; in addition, it does not require to supply in a borehole electrical energy.
This technical result is achieved by the fact that, in accordance with the proposed method of determining the profile of thermal conductivity of rocks is lowered into the well casing attached to its outer surface temperature sensors, pump cement into the annulus between the casing and the borehole wall during injection and curing of the cement carry out temperature measurements to determine thermal conductivity surrounding the borehole rocks by the formula
where λ(z) is thermal conductivity of the rocks at depth z, Qcis the heat of hydration of cement, Va(z) - volume of the annular gap, per meter of length of the borehole at the depth z, C(z) is the coefficient determined by the method of linear regression when the approximation of dependence measured in borehole temperature T(z,t) from the inverse time t-1asymptotic formula
where Tƒ(z) is the temperature of the rocks at depth z.
As temperature sensors can be used in fiber-optic sensor.
The invention is illustrated by drawings, where Fig.1 shows the geometry is cylindrically symmetric model, which was used in the calculations of Fig.2 - the results of numerical modeling of the temperature dependence of the cement from the inverse of the time elapsed after the start of hydration for two values of thermal conductivity of rocks.
As shown in Fig.1, in accordance with the invention for the temperature monitoring of the injection process, and hardening (hydration) of the cement and the subsequent temperature monitoring oil/gas or injection of fluid 1 in the hole, surrounded by rock 4, vacation is t casing 2 is attached to fiber cable 5 meter temperature.
During the hydration of cement 3 pumped into the annulus between the casing 2 and the borehole wall, there is a considerable amount of heat release (Qc=100÷200 MJ per 1 m3cement mortar). The maximum temperature increase during hardening of cement is approximately 20-50°C. the Main stage of cement hydration (and heat) lasts 30-50 hours, after which the radius of the area with increased temperature increases and the temperature in the hole relaxes to the undisturbed temperature of the rocks at this depth.
The relaxation rate of the temperature depends on the amount of excess thermal energy Q per 1 m length of the borehole, and thermal properties of the rocks surrounding the borehole. Excess heat energy Q can be found as the product measured in the laboratory of heat of hydration of cement Qcand volume of the annular gap, which is defined by the outer radius of the casing rcoand measured with the help of caliper radius of the well, depending on depth z: rw(z). Thus, the recovery rate of the temperature in the borehole after cementation is determined solely by thermal properties of the surrounding rocks.
Below is a theoretical model that is used as the basis for the determination of the heat its the government of rocks measured in the borehole depending on the temperature from time to time.
Known solution to a cylindrically symmetric tasks conductive conductivity on the evolution in time of an arbitrary initial temperature distribution in a homogeneous medium (see, for example, Carslaw,, Eger D. thermal Conductivity of the solid tel. M.: Nauka, 1964, S. 88). In particular, if the initial temperature distribution having the form of a cylinder
the time dependence of the temperature in the center of this cylinder has the form
where r0is the radius of the cylinder, 'and' is thermal diffusivity of the medium.
At sufficiently large times after the beginning of the relaxation temperature (
This formula can be written in the General form of the energy conservation law (by multiplying the numerator and denominator of (3) to the multiplier π·ρ):
Numerical experiments show that the generalized asymptotic formula (4) are valid for any initial temperature distribution. Thus r0there is a characteristic size of the region in which the initial temperature is substantially different from the ambient temperature, and the required condition is met:
Formula (4) shows that if the initial thermal perturbation in a cylindrically symmetric problem set as the number of excess heat in a homogeneous environment, the asymptotic behavior of the temperature is determined solely by thermal conductivity of the environment.
In this case, the environment is heterogeneous (Fig.1): borehole fluid (0<r<rci, rcithe inner radius of the casing), casing (rci<r<rco, rco- the outer radius of the casing), cement (rco<r<rw, rwis the radius of the borehole) and rock (rw<r), has a significantly different thermal properties. However, as shown by numerical calculations, the asymptotic who ormula (4) accurately describes the change in borehole temperature over time. This is due to the fact that at large times the increase in the radius of the heated zone is determined solely by thermal conductivity of the rocks, and the radial temperature variations near the well small.
In this case, the excess thermal energy Q is determined by the product of heat of hydration of cement Qc(J/m3and the volume of the annular gap Va(m3one meter length of the borehole)
where L is the depth interval used for averaging volume of the ring is the first gap. A typical value of this parameter L=2÷3 m, it gives a vertical resolution of the proposed method. The value of L is determined by the smoothing effect of the vertical conductive heat transfer in the rock and the typical time scale of the measurements.
If the unperturbed temperature Tƒ(z) breeds on the depth z is known, thermal conductivity of the rocks λ(z) is determined by the value of the function F(z,t) at large times (t>t0):
Time tmmust be greater than the duration of the main phase hydration of the cement and the time at which it becomes applicable asymptotic formula (4). A typical value of tm=100-150 hour the century
Usually unperturbed temperature rocks Tƒ(z) is unknown and thermal conductivity of the rocks are encouraged to identify as follows.
The measured temperature values at t>tmapproximate the asymptotic formula (at the time of hydration over 100 hours)
In this method of linear regression to find the parameter C(z) and the temperature of the rocks Tƒ(z), which is not used in the subsequent calculation of thermal conductivity.
The parameter C is used to calculate thermal conductivity of rocks by the formula:
The proposed method of determination of thermal conductivity of rocks has been tested on synthetic cases, prepared using a commercial simulator Comsol. The geometry is cylindrically symmetric model, which was used in the calculations are shown in Fig.1.
The inner and outer radii of the casing is equal to rci,=0.1 m, rco=0.11 m, the radius of the hole rw=0.18 m, the outer radius of the computational region is STI r e=20 m Used in the calculations of thermal properties of the borehole fluid (the effective thermal conductivity, taking into account the free thermal fluid), casing, cement and rock are given in the table.
|TC W/(m·K)||ρ, kg/m3||C, j/(kg·K)|
|Fluid||3 (effective value)||1000||4000|
|Rock||1 and 2||2700||1000|
We used the following analytical formula for the power of the heat of hydration of cement q(t):
Calculations were performed for the following parameters characterizing the heat generated by cement hydration: Qc=1.5·108J/m3, t0=6 h, t1=8 hours.
In Fig.2 shows the calculated dependence of the temperature in the annular gap at a distance of 0.13 m from the axis of the borehole from the inverse time t-1with-1(the time interval 300-100 hours from the beginning of the hydration of cement) for two values of thermal conductivity of rocks: λ=1 and 2 W/m·K. the regression equations and the white lines correspond to the linear approximation of the numerical simulation results. The initial temperature was taken equal to zero. In the time interval calculated dependences are well described by straight lines (9). Shown in the figure, the regression equations have close to zero free members (0.0283 and 0.0473), which corresponds to zero initial temperature, and substitution in equation (10) coefficients of the regression equation (1 W/m·K)=703030 and(2 W/m·K)=387772) gives the following values TopLop is bednesti rocks: 1.07 and 1.96 W/m·K.
You can increase the accuracy of determination of thermal conductivity of rocks and significantly reduce the required duration of temperature measurement, if the solution of the inverse problem is to use numerical modeling of the hydration process of the cement in the well.
1. The method for determining the profile of thermal conductivity of rocks in the borehole, in accordance with which it is lowered into the well casing attached to its outer surface temperature sensors, pump the cement slurry in the annulus between the casing and the borehole wall during injection and curing of the cement carry out temperature measurements to determine thermal conductivity surrounding the borehole rocks by the formula
where λ(z) is thermal conductivity of the rocks at depth z, Qcis the heat of hydration of cement, Va(z) - volume of the annular gap, per meter of length of the borehole at the depth z, C(z) is the coefficient determined by the method of linear regression when approximating the dependence of the measured downhole temperature Tz,t) from the inverse time t -1asymptotic formula
where Tf(z) is the temperature of the rocks at depth z.
2. The method according to p. 1, whereby as the temperature sensors use fiber-optic sensor.
3. The method according to p. 1, according to which to determine thermal conductivity of rocks using numerical simulation of the hydration process of the cement in the well.
FIELD: measurement equipment.
SUBSTANCE: invention relates to a method for acquisition and processing of geochemical survey data, which represents a gradient method of geochemical survey. The method involves acquisition at each sampling point of a set of samples by alternating sampling of soil samples and gas samples at the interval of 0.5-1 m downwards from ground surface. Then, analysis of soil and gas samples for their geochemical indicator or indicators is performed, and charts of geochemical indicator(s) and charts of its gradient depending on depth are built as per analysis results for each sampling point. Formation of profiles of geochemical indicator(s) and profiles of its gradient is performed for each depth; with that, the profile is built along the survey line. As per the obtained charts, isolines of geochemical indicator(s) and isolines of its gradient for the profile are built, as per which three-dimensional viewing diagram of the collected data of the area is formed. After that, determination as per characteristics of variations of geochemical indicator(s) is performed depending on depth and abnormalities of its gradients in the three-dimensional viewing diagram of the area rich in metal ores or deposits.
EFFECT: acquisition of large amount of information, namely information on longitudinal variations, other than common geochemical survey.
5 cl, 5 dwg
FIELD: oil-and-gas industry.
SUBSTANCE: results of seismics are used to define the volumes of geological space confined by time-important geological boundaries, surface of bedding and structural erosion unconformities and their hierarchy. Seismic-stratigraphic model of the earth's core is constructed to reconstruct the sedimentary field evolution with subsequent determination of rock properties and porosity distribution. Density model of sedimentary jacket section model is created to define hydraulic system state at definite time intervals so that abnormally high pressures are revealed. Oil-and-gas deposits are revealed from abnormally high pressure distribution and variation pattern.
EFFECT: higher efficiency of forecast.
FIELD: measurement equipment.
SUBSTANCE: invention relates to hydrodynamic and hydrochemical tests of waters of peat soils. According to the method, there determined is a law of distribution of a set of balance coefficients during different periods of unidirectional processes characterising relationship between chemical and hydrodynamic processes flowing as to thickness of a peat deposit. Flow rates of the incoming water are determined with a sampling complex. A calculation of balance coefficients of the obtained data is carried out by a unification method. They are brought to a uniform dimensionless form by a mathematical generalisation method. Change of a set of balance coefficients allows efficient assessment of a degree and dynamics of change of chemical water composition and its hydrodynamic mode due to duration and intensity of processes. Persistent interaction of balance coefficients distributed in time and depth shows balance of a swamp ecosystem.
EFFECT: determination of change of chemical composition of swamp waters as to depth of a peat deposit under conditions of their hydrodynamic mode in time.
8 tbl, 9 dwg
FIELD: measurement equipment.
SUBSTANCE: invention relates to the field of geodetic monitoring and may be used for tracking of changes in Earth crust and forecasting of earthquakes. Substance: using the geodetic method, they detect dynamic shifts along the lines perpendicular to a seismogenic split (11). Besides, measurements are carried out at control stations, which are installed along or near the lines perpendicular to the seismogenic split (11). Control stations are made with permanent installation of base stations (9) or receivers (10) of satellite navigation on them. Base stations (9) and receivers (10) of satellite navigation are installed under shelters. Opening and closure of the upper part of shelters (roof) is remotely controlled. Modules of remote control and data collection, designed for transfer of collected data along wireless communication to the centre of their collection and processing are connected to each base station (9).
EFFECT: increased efficiency and accuracy of forecasting.
9 cl, 5 dwg
SUBSTANCE: invention may be used to determine paleotemperatures of catagenesis that characterises the degree of catagenetic maturity of organic matter (OM) of rocks. The sampling of sediments is carried out from the studied rocks, the insoluble organic matter microphytofossils is isolated from them and studied with optical method with the determining of paleotemperature. The study with the optical method is carried out in two stages. At the first stage in transmitted light the dominant group of microphytofossils is isolated from the morphological groups of microphytofossils, the groups of thick-walled and thin-walled microphytofossils is isolated in it. For each isolated group the index of colour is determined. At the second stage of the study the quantitative characteristics are clarified on the basis of spectral characteristics of selected groups of microphytofossils in infrared band of light. The resulting estimates of paleotemperatures of microphytofossils are determined on the basis of comparing the results of studies of the first and second stages.
EFFECT: improving reliability of determining paleotemperatures of catagenesis of vitrinite-free deposits.
2 cl, 1 dwg, 2 tbl
SUBSTANCE: geological sampling is made according to test grid. Samples are prepared by crushing, grinding, reduction, division and taking analytical samples. Gold content is defined in analytical samples. Rich and lean sections of gold ore deposit sections are isolated with allowance for accepted conditions. Industrial mineralisation of gold ore deposit is delineated. Then extra geological samples are taken at lean sections at least three paces from the boundary of rich section. Extra geological samples are prepared. Analytical samples are taken in weight at least twice as heavy as the main analytical sample. Every extra analytical sample is processed in centrifugal field with at centripetal acceleration over 25 units of free fall acceleration to produce concentrates and tails. Gold content is defined in said concentrates and tails to calculate it in terms of appropriate extra sample. Results of said calculations are used to refer said section to industrial mineralisation with refinement of delineation.
EFFECT: higher accuracy of industrial mineralisation delineation.
SUBSTANCE: method involves interturn differential interferometry of the surface of the Earth to obtain pairs of complex radar images. Pairs of complex radar images which form an interference pair are obtained on time-separated turns. The pairs of complex radar images are recorded in accordance with tidal phases of the Moon and the Sun. The obtained differential interferometric images are compared with reference interferometric images. Upon detecting considerable differences between said images, parameters of the stress-strain state of the Earth's crust are calculated and the danger posed by damage thereof is evaluated.
EFFECT: high accuracy of detecting possible catastrophic phenomena.
FIELD: physics; geophysics.
SUBSTANCE: invention relates to geology and can be used to predict development zones of secondary fracture-type reservoirs in a sedimentary section. The method involves detecting reflected seismic waves associated with a selected system of deposits; performing lithologic-petrophysical investigation of rock samples to determine the most probable genesis of secondary reservoirs; selecting lithotypes on which secondary fracture-type reservoirs are formed; drilling a well in anticline structures and determining the depth of occurrence of fold hinges, morphologic parameters of the structures, including maximum seam contortion, width, length, area and intensity of folding; using downhole logging results to determine secondary porosity; measuring formation pressure in test intervals; establishing a critical value of secondary porosity Kpvtcr; establishing a multidimensional correlation relationship of the secondary porosity Kpvt=f(i, gradp, J, Kpob, H), where i is the maximum seam contortion; gradp is the gradient of formation pressure; J=i/S is folding intensity; S is the surface area of the structure; Kpob is the overall porosity; H is the depth of occurrence of fold hinge; performing detailed field seismic survey on unstudied areas of the territory with a dense seismic grid through not more than 100 m; processing field seismic materials; detecting presence of anticline structures and deep faults; constructing seismic-geologic profiles along and across the detected structures; determining the depth of occurrence of vfold hinges and morphologic parameters of the structures; using the established relationship Kpob=f(H) to determine overall porosity at the depth of occurrence of the bedrock on newly detected structures; determining the predicted gradient of formation pressure; using the established multidimensional correlation relationship of secondary porosity Kpvt=f(i, gradp, J, Kpob, H) to predict the value of Kpvt; comparing Kpvt with the lower limit of Kpvtcr for the "reservoir-nonreservoir" boundary, which is then used to predict the probability of development of secondary fracture-type reservoirs, the expediency of drilling on said structures and the well drilling procedure. If Kpvt/Kpvtcr>1.2, it is expedient to drill on a profile of three dependent wells; if Kpvt/Kpvtcr=(0.7-1.2), drilling only one well in the crest of the structure is expedient.
EFFECT: high efficiency of prediction.
1 dwg, 5 tbl
SUBSTANCE: invention refers to the methods of detecting the forerunners and can be used to identify the possibility of earthquakes in the Baikal Lake region. The invention concept is as follows: water samples are taken from the zone of intersection of deep breaks in the Baikal Lake territory where earthquakes of different intensity took place repeatedly. Sampling is performed by a water intake structure comprising a deepwater intake (8), an electric pump (9) set at the water intake station on the Baikal bank, filters for coarse (10) and fine (11) treatment of water. Concentration of helium dissolved in the deep water is examined. A conclusion on possible earthquake is made on the basis of the curves of the helium concentration variation.
EFFECT: detection of a possibility that an earthquake will occur.
2 cl, 4 dwg
FIELD: physics; geophysics.
SUBSTANCE: invention relates to geoexploration and can be used to determine different properties of hydrocarbon formation fluids. The invention discloses examples of methods, apparatus and articles of manufacture for process measurements of strings vibrating in fluids. A disclosed example of an apparatus includes a downhole assembly and a surface assembly. The downhole assembly 300 includes a sensor 305, 325 for measuring a waveform representative of a motion of a string vibrating in a fluid at a downhole location in a wellbore, a waveform simulator 332 for computing a model parameter based on the measured waveform, and a first telemetry module 340 for transmitting the computed model parameter to a surface location. The surface assembly includes a second telemetry module for receiving the computed model parameter from the downhole assembly, and a viscosity analyser for estimating a viscosity of the fluid based on the computed model parameter. The method of processing measurements of strings vibrating in a fluid involves an operation for measuring a waveform and computing a model parameter of vibration of the string based on the measured waveform. Said model parameter is used to determine viscosity of the formation fluid.
EFFECT: high accuracy of determining properties of formation fluids.
32 cl, 7 dwg
FIELD: oil and gas industry.
SUBSTANCE: method includes measurement of indicator diagram of well flow rate dependency on pressure drawdown and determination of the dependency peak corresponding to optimal pressure drawdown. Elastic strain dependency is measured, for example, propagation rate of elastic rate from porosity pressure in a core sample selected from the formation and placed into the hydraulic chamber with uniform pressure corresponding to conditions of natural occurrence, then porosity pressure is reduced smoothly up to the formation pressure with rate that does not exceed relaxation rate of limit strain in the core, which is used for assessment of acoustic emission non-availability, and then porosity pressure is continued to reduce as the core drawdown, and against commencement of sharp change in this dependency gradient reduction when plasticity limit is reached and acoustic emission occurs the limit value of optimal pressure drawdown is assessed.
EFFECT: improving accuracy in determination of optimal pressure drawdown.
SUBSTANCE: in killed well temperature is measured, and the temperature change rate is measured in the depth intervals located within the productive formations, and in the depth intervals located in immediate proximity from productive formations. In the depth intervals located within the productive formations, the sections are separated, the temperature change rate in which is much higher than the temperature change rate in the depth intervals located in immediate proximity from productive formations. The numerical model of temperature change in a killed well is developed which takes into account the influence of formation fluid filtering at the temperature change rate in the killed well, the measurements results are compared with the results of numerical simulation and using the best agreement of measurement results and simulation results the filtration rate of formation fluids in the depth intervals located within the of productive formations are determined.
EFFECT: identification of depth intervals, where fluid flow occurs, and estimation of rate of their filtering in the location of observation well.
8 cl, 7 dwg
FIELD: oil and gas industry.
SUBSTANCE: method of oil and gas condensate multipay field development includes based on the basis of seismic data and exploratory and operation drilling data identification of depths of occurrence, areas and net pays, plotting of subsurface maps, performance of detailed cross-borehole correlation with specification of boundaries for claying, bed thinning and tectonic disturbance, determination of permeability and porosity of collectors against data of standard and special experiments with core material, determination of initial pressure and temperature in the stratum against data of measurements made with a depth gage and of initial composition and properties of the hydrocarbon system saturating the stratum against results of laboratory researches of gas condensate characteristic, in process of commercial operation monitoring of the deposit development indices including measurement of bottomhole pressure and temperature, consumption rates of gaseous and liquid phases in the production system, field pipeline transfer and preparation of hydrocarbon products, performance of gas dynamic, gas condensate surveys and downwhole logging. Thereafter analysis of the development monitoring results is made, a numerical filtration model of the deposit is created on the basis of compositional approach and the model is adapted in two stages. Each of stages represents an exact algorithm excluding impact of each subsequent adaption step to results of the previous one. At the first stage material balance of hydrocarbon pseudo components is set for the deposit envisaging compliance with precise volume and mass production of the formation gas at the facility as a whole considering values of formation pressure. At the second stage the model is set for data of long-term operation of wells. At that values of bottomhole and wellhead pressure, group production of the formation gas are used as parameters for quality control of the model. Additional parameters of control include distribution of production by wells considering results of gas condensate surveys, inflow profile in compliance with bottomhole logging, values of formation pressure by wells, which are received on the basis of hydrodynamic research data. Upon adaption of the model in the above way and specification of characteristics of filtration and phase transitions in oil and gas condensate systems the model is started to calculate forecast of the development cost-performance ratio and, in result, basing on this model process modes for operation of wells, loops and gas processing facilities are defined against production levels for short-term and long-term prospects ensuring high final recovery factors of hydrocarbon products.
EFFECT: improving accuracy for determination of optimal process mode for operation of wells, loops and gas processing facilities against production levels for short-term and long-term prospects.
FIELD: physics, computer engineering.
SUBSTANCE: invention relates to a method, a device and a computer-readable data medium used when constructing a geologic model of an oil or other deposit. The invention enables, for markers selected as the initial solution, to calculate marker depths at each well which provide the best overall correlation. The method includes determining, for each marker which is part of a set, a composite function which is the sum of correlation coefficients of a system of well logging techniques for pairs of wells located no more than a given distance from each other. Partial derivatives are calculated for said composite function and the obtained vector is smoothed and used to find a greater value of the composite function at a certain section along said vector. If a greater value is not found, the last position of the marker is considered the solution, otherwise the solution point is smoothed and the process is repeated. The marker depths are sorted at each algorithm iteration.
EFFECT: improved accuracy of calculation of parameters used to construct a geological model of the location of oil or other deposits.
3 cl, 9 dwg
FIELD: physics, computer engineering.
SUBSTANCE: invention relates to a method, a device and a computer-readable data medium used for building a geological model of an oil or other mineral deposit, particularly for determining correlation coefficients for a set of well-logging curves and finding the position of marker depths, for which the correlation coefficient value is maximum. The method enables, for a marker already having marks at a certain so-called reference group of wells, to calculate said marks for a well from another group. For each well W, on which the marker depth value is being searched for, wells of a reference group lying at a given distance from well W are selected, and from among them a well is selected with the highest correlation coefficient, wherein the point at which said maximum is reached is denoted as the desired mark of the marker. Verification tests are used to search for wells in which the correlation function is less than the maximum correlation coefficient, and the correlation quality coefficient is greater than the maximum correlation coefficient. The found well is added to the reference group of wells.
EFFECT: improved accuracy of calculation of parameters used to build a geological model of the location of oil or other deposits.
8 cl, 9 dwg
FIELD: oil and gas industry.
SUBSTANCE: method of hydrodynamic research for gas-bearing formations without gas release to the surface includes running in at the drill string of flow string of the testing equipment in the form of a formation tester with a packer and geophysical sensors to the preset research interval of the gas-bearing formation. The research interval is isolated by the packer upstream the gas-bearing formation. Influx mode and pressure recovery mode are created in sequence and the further interpretation of the received data is made. At that in process of the testing equipment running in to the drill or flow string the design quantity of at least two-component viscoelastic mixture with the target parameters of viscosity and elasticity is poured additionally; the mixture is made without a crosslinker and based on polyacrylamide and zeolite or mud powder; above the testing equipment assembly it creates a viscoelastic plug. The plug ensures creation of depression to the value not exceeding 10-20% of the expected formation pressure. Further the hydrodynamic research is made as per the drill stem test procedure.
EFFECT: improving accuracy and efficiency of the research.
FIELD: oil-and-gas industry.
SUBSTANCE: proposed method comprises several steps. At first step, temperature control unit is switched on to inject reservoir water in the model to define reservoir model reservoir model capacity. At second step, temperature control unit is switched off to inject liquid industrial wastes in well model to define reservoir model industrial liquid wastes capacity. Degassing is performed at reservoir model outlet before measurement of reservoir water and industrial wastes flow rates. Compatibility of liquid industrial wastes with reservoir water is established in case reservoir water capacity differs from that of liquid industrial wastes by not over 20%.
EFFECT: higher efficiency.
FIELD: oil-and-gas industry.
SUBSTANCE: proposed method comprises determination of drilling mud rheological properties, drilling mud filtrate and formation fluid, measurement of outer filtration crust, porosity and permeability of core specimen. Note here that mathematical model of said outer filtration crust if constructed. Drilling mud is forced through core specimen to register pressure drop dynamics at specimen and flow rate of effusing fluid. Micro tomography is used to define the profile of drilling mud solid particles penetrated into said specimen. Mathematical model of inner filtration crust is constructed to describe the dynamics of drilling mud particle concentration in threshold space of core specimen and associated changes in core specimen permeability. Enchained mathematical model of inner and outer filtration crusts is constructed. The latter allows the determination of parameters of inner filtration crust mathematical model whereat reproduced are experimental; data on pumping said drilling mud through core specimen and profile of drilling mud solid particles penetrated into said specimen.
EFFECT: higher accuracy and lower labour input.
1 cl, 8 dwg
FIELD: oil-and-gas industry.
SUBSTANCE: proposed method comprises filtration experiments with cores under stationary conditions, plotting of fluid filtration rate against pressure gradient, determination of ultimate pressure gradient corresponding to fluid filtration pattern variation. Additionally, filtration experiments with different-permeability cores are carried out under non-stationary conditions to define dependence of ultimate pressure gradient on permeability and to construct formation pressure gradient modulus map and permeability map. Quadratic net is applied on seam pressure gradient modulus map and permeability map. Seam pressure gradient modulus and permeability factor are evaluated for every cell of the net. Dependence of limiting pressure gradient on permeability is used to calculate the limiting pressure gradient for every cell of the net. Obtained magnitudes are compared with seam pressure gradient modulus. Cells are isolated wherein seam pressure gradient is lower than limiting pressure gradient to define dead and slightly drainage zones of oil deposit.
EFFECT: determination of dead and slightly drained zones of oil low-permeability deposits.
FIELD: oil-and-gas industry.
SUBSTANCE: deposit contains the rock of valuable mineral and the other mineral. Proposed method comprises steps that follow: drilling for rock extraction, registration of predefined drilling parameter, registration of measured magnitude describing drilling unit operating conditions and computation of exclusion of measured magnitude dependence on drilling parameter. Characteristic dependent on rock texture is obtained. This characteristic is used as the measure of mineral grain for valuable mineral in rock and for definition of optimum grinding of minerals at rock grinding.
EFFECT: increased yield.
16 cl, 4 dwg
FIELD: oil and gas industry.
SUBSTANCE: device includes a mechanical oscillating system with constant magnets fixed on it and a converter of mechanical oscillations to electrical ones. A mechanical oscillating system is made in the form of a cylindrical bimetallic spiral, one end of which is rigidly fixed, and the other one is free, and the converter of mechanical oscillations to electrical ones is made in the form of a system of interacting electromagnetic fields of constant magnets rigidly fixed on a cylindrical bimetallic spiral and coils of a drive and pickup of oscillations providing for transverse oscillations of the cylindrical bimetallic spiral.
EFFECT: enhancing reliability of a device and improving its design.