Development method of oil deposit at late stage

FIELD: oil and gas industry.

SUBSTANCE: method involves drilling of production and injection wells, pumping of displacement agent through injection wells and extraction of the product through production wells, drilling of additional wells, and development of residual oil-saturated intervals. According to the invention, in all newly drilled additional wells there determined are residual oil-saturated and flooded intervals prior to the well casing. For that purpose, one-stage determination of temperature field is performed throughout the length of the well in real time both at filling of the shaft with heated washing liquid or water and after it is filled using an optic-fibre system. In case of absorption of washing liquid or water, volume of their supply, which provides full filling of the well, is increased. After the well casing residual oil-saturated and/or water-saturated intervals are developed, and displacement agent is extracted and/or pumped.

EFFECT: increasing oil recovery owing to improving the accuracy of determination of intervals of arrangement of water-saturated and residual oil-saturated zones.

1 dwg

 

The invention relates to the oil industry and can find application in the development of oil deposits.

There is a method of determining the boundaries of the deposits on the results of well testing (rahimkulov IVAN TO the interpretation of the results of the study heterogeneous reservoirs. Izvestiya Vuzov. - Baku: Oil and gas 8, 1964, p.31-37).

The disadvantage of this method is the necessity to use when determining the boundaries of the deposits factor piezoconductivity, which define, among themselves hydrodynamic studies, which introduces additional uncertainty in the results of the determinations of the size of the Deposit and thereby and oil reserves, however, this method does not provide the search for oil deposits inside the mine.

There is a method of developing a heterogeneous oil field (patent RU №2259474, IPC 8 EV 43/20, publ. 27.08.2005 g)providing for the drilling of injection and production wells, the flooding of the reservoir and removing the oil on the surface, the refinement of the geological structure of the drilling and modeling and drilling additional wells with lateral or horizontal wells from old wells, location of zone boundaries replacement collectors, additionally calculate the quantity of fixed oil, concentrated near Thames is of collectors, then carry out the drilling of horizontal wells from old wells located near the borders of zones of replacement of sewers and/or new wells with a horizontal shaft in this area, and horizontal trunks Buryats in the direction perpendicular to the boundary of substitution.

The disadvantage of this method is that it does not allow you to enter into the development of residual oil saturated intervals located within the vicinity of the rupture zones of substitution collectors, characterized by low value end of the oil recovery factor.

Also there is a method of determining the oil deposits (patent RU №2186211, IPC 8 EV 43/20, publ. 27.07.2002,), according to which on the site of the Deposit determines the location of the axis of the deposits, conduct hydrodynamic studies well, not lying on the axis of the reservoir, with the duration of the study, providing on the curve of the recovery pressure of the two reflected signals pressure from near and far boundaries of the reservoir, determine the time of the parishes of the reflected signals pressures from near and far edges of the Deposit and bandwidth deposits. The volume of the reservoir, reservoir properties and the properties of the reservoir fluid determine the oil reserves.

This method allows you to define the boundaries of the deposits, but cannot discover within the field bypassed zones on is enough oil and deposits, and to identify water-bearing zones.

Method development of an oil field (patent RU №2417305, IPC 8 EV 43/20, publ. 27.04.2010, including the selection of oil through the production wells, injection working agent through the injection wells and the delimitation of the deposits, with the delimitation of the deposits analyze the position of the oil-water contact in the wells, are a long time in simple, by the position of the oil-water contact in the wells from the top to the bottom determine the direction of water flow in the field, in the direction of water flow release patterns with existing steep slopes or lock, to analyze this structure, the height and width of the pilot-operated check valve, when the ratio of height to width of the structures of more than one structure qualify as a Deposit, perforined existing reservoirs wells in the selected structures and/or deepen existing wells in selected patterns, and/or are drilling production wells on a dedicated structures and selected oil.

The disadvantages of this method are:

firstly, the duration of the method when determining bypassed intervals of residual oil within the field prior to perforation (opening), while the ratio of height to width of more than one structure, the structure qualify as a reservoir that mo is et to cause an error during the subsequent autopsy intervals residual zones of oil and as a consequence, incomplete development of areas with residual oil;

- secondly, the low accuracy of determination of the intervals of the water-saturated zones, which determine the position of the oil-water contact in the wells from the top to the bottom and determine the direction of water flow in the field, which can change over time and subsequent autopsy intervals residual zones of oil possible error and, as a result, the opening vodonosnyh (flooding) intervals deposits, which will lead to premature flooding deposits.

An object of the invention is to improve the accuracy of the determination of the intervals of placing water-saturated zones and residual oil saturation zones geological sections penetrated by wells within the Deposit and the reduction in the duration of the method.

The technical problem is solved by way of the development of oil deposits at a late stage, which includes the drilling of production and injection wells, injection of the displacing agent through the injection well and the selection of products through the production wells, the drilling of additional wells, the opening of residual oil saturated intervals.

What's new is that all newly drilled additional wells to determine residual oil saturation and flooding intervals to discuss the lid of the well, to do this, carry out the simultaneous determination of the temperature field along the entire length of the well in real time as when filling the barrel heated washing liquid or water, and after filling with the use of fiber-optical systems and in the case of washing fluid absorption or increase the amount of water submission, ensuring complete filling of the wells, after install wells reveal residual oil and/or water-saturated intervals and produce a selection and/or injection of the displacing agent.

The proposed method aims at maximum involvement in the development of residual neftenosnykh zones of oil deposits with regard to water-saturated zones by increasing the accuracy of determining the intervals of placing the oil - and water-saturated zones in the geological borehole and, as a consequence, the enhanced oil recovery at a later stage of development.

The drawing shows schematically thermogram.

The essence of the proposed method is as follows.

The way of the development of oil deposits includes the drilling of production and injection wells (design grid development). The injection of the displacing fluid into the injection well and the selection of products through the production wells. In the process of developing oil reserves are depleted and the Deposit gradually watered with p and its further development becomes economically inefficient, but at the same time remain a zone of residual saturation. To generate the remaining oil reserves and reducing the water content of produced fluids (oil) on oil fields produce the drilling of new wells (on any known grid development).

In the newly drilled (optional) wells before service (casing and cementing) wells produce fiber-optic system borehole thermometry (temperature measurements in the borehole) to study the temperature distribution throughout the geological section opened by the well and determine the geothermal gradient to determine residual oil saturation intervals. Fiber-optic borehole thermometry includes fiber optic cable, such as fiber-optic cable to measure the temperature distribution in the steam wells (patent RU №2238578, IPC 8 G02B 6/44, publ. in bull. No. 29 dated 20.10.2004,), which is installed alternately or simultaneously in several of the newly drilled wells from the mouth to the bottom, and an electronic unit mounted on the surface of each well, which produce thermometry, when this optical fiber is simultaneously distributed temperature sensor, and channel information transfer from the wellbore to the surface the th. Measurement of thermal field wells is performed by determining changes in temperature along the optical cable is placed in the wellbore from the mouth to the bottom, relative to the reference segment of the fiber in the electronic unit of the device.

Further, in the borehole, in which the flat fiber optic cable connected to the electronic unit on the surface of the wells pumped water, such as fresh water density ρ=1000 kg/m3or washing fluid used during the drilling of this well, and in any case at a temperature of 80-100°C. When filling the wells with washing liquid or water having a temperature of 80-100°C remove thermogram on the electronic unit, with the resulting thermogram of the wellbore is recorded in real time (see figure 1).

In the case of washing fluid absorption or increase water flow to fill the well. For example, on thermogram shows that water-saturated intervals of the wells are located at intervals of 750±10 m and 1560±10 m, where there is a faster cooling water (washing liquid) due to the higher thermal conductivity of water-saturated (flooding) zone temperature falls below 60°C, while in the intervals of oil-saturated zone: 1320±5 m and 1730±5 m temperature drops to 70°C due to the smaller ones is doprovodnou saturated zones in comparison with water-saturated zones.

The principle of distributed temperature sensors based on the effect of spontaneous Raman scattering in the material of the fiber-optic light guide and the technology of optical reflectometry. Laser pulse propagating along the fiber interacts with the material, in this part of the photons scattered in the opposite direction, carrying information about temperature fluctuations of the molecules, respectively, from the spectrum of the scattered radiation can provide information about the temperature along the optical fiber. The system is based on the temperature change of the optical fiber laid along the geological section opened by the well. The main difference between the system of the distributed monitoring of the temperature field of the extended object from the traditional point of thermometers is the possibility of simultaneous determination of the temperature field of the controlled object along its length in real time. In addition, it should be noted reliability and long term operation of fiber-optic system, high stability and noise immunity of the cable sensor that provides the distributed system thermometry during the overhaul period or life of the well.

It is also possible monitoring in real time deposits as a whole through thermome theory of the productive series with fiber logging cable, installed in several wells in total deposits, while ensuring the current geological and hydrodynamic models of deposits.

The high temporal frequency of subsequent measurements allows to obtain three-dimensional graph, the length of the time-temperature (not shown), which guarantees the user the ability to identify existing anomalies of the temperature field in real time. When conducting thermometry in flooding intervals faster cooling water (washing liquid) due to the higher thermal conductivity of water-saturated (flooding) areas, as evidenced by the data thermometry, which allow flooding of the intervals or the intervals of oil (not flooding) residual oil.

Then in the newly drilled (optional) wells produce casing and cementing with the opening (perforation) of the residual oil saturated intervals in the geological section of the wells are equipped with operational equipment and launch additional wells as producing or injection, respectively, under the selection of oil from the oil-saturated zone or injection of the displacing agent (water) in the oil-saturated zone deposits, for example in the case of selection and contour flooding deposits.

When is neobhodimosti open (perforined) and the intervals of saturated areas such as inter-well pumping (SMEs) water from one well to another or downhole pump (VSP) water, for example from an aquifer in oil or simultaneous selection and injection of water into a borehole. Thus, continue the development of oil deposits at a later stage to complete development of the residual oil saturation zones.

Application of the proposed method of development of oil deposits at a later stage can improve the accuracy of determination of the intervals of placing water-saturated zones and residual oil saturation zones geological sections penetrated by wells within the reservoir and to reduce the duration of the method by conducting fiber optical system borehole thermometry that allows dissection, perforation of the casing) only in oil saturated intervals of residual oil deposits, which, in turn, allows us to produce products with less water content, to increase oil production and, consequently, to increase the coverage of the strata development (flooding) and, as a result, to increase the ultimate oil recovery.

The way of the development of oil deposits at a late stage, which includes the drilling of production and injection wells, injection of the displacing agent through the injection well and the selection of products through the production wells, the drilling of additional wells, the opening of residual oil saturated intervals, characterized in that all again prober is the R additional wells to determine residual oil saturation and flooding intervals to install wells, to do this, carry out the simultaneous determination of the temperature field along the entire length of the well in real time as when filling the barrel heated washing liquid or water, and after filling with the use of fiber-optical systems and, in the case of washing fluid absorption or water, increase the amount of their feed, ensuring complete filling of the wells, after install wells reveal residual oil and/or water-saturated intervals and produce a selection and/or injection of the displacing agent.



 

Same patents:

FIELD: oil and gas industry.

SUBSTANCE: electric motor of a submersible pump can be equipped with two rotary shafts, and namely an upper one that is more rotary and a lower one that is less rotary, which are controlled with one common or two different individual current supply cables and connected to the submersible pump and a shutoff element. Lower electric motor is provided with the less rotary shaft controlled with a common or an individual current supply cable. The shutoff element consists of an upper rotating bar and a lower movable bar, which are connected to each other by means of screw thread. The rotating bar is connected from above with the less rotary shaft through a spline square or a hexagon and installed in the housing with possibility of being rotated only on the axis to one and another sides. The movable bar is connected from below between two pass assemblies in the form of mounting seats or seats with a shutter installed in the housing with possibility of being moved only along the axis till tight closing of above and below located mounting seats to assure the possibility of both the control and cutout of the fluid flow of the corresponding formation.

EFFECT: improving reliability and efficiency of the plant.

2 cl, 5 dwg

FIELD: oil and gas industry.

SUBSTANCE: system includes control centre of electric-centrifugal pump to power transformer is connected and output of the transformer is connected by power circuits of submersible cable through input lead with submersible electric motor. In downhole part control unit is connected to power supply source by one input and to the first input/output of the amplifier by the other input/output. The second input/output of the amplifier together with input of power supply source is connected through a pressure-seal connector to independent signal circuit formed by transit insulated conductor laid between stator pack and housing of submersible electric motor connected at the other end through input lead with signal core of submersible cable. In surface part this core is connected to output of remote power supply and to the first input/output of transceiver which second input/output is connected to the first input/output of surface control unit and its second input/output is connected to input/output of the control centre of electric-centrifugal pump. The third output is connected to input of remote power source. The amplifier in downhole part and transceiver in surface part are designed to ensure half-duplex operation during data exchange as bidirectional network. Input lead assembly of submersible electric motor is made according to four-contact circuit. In the downhole part independent signal circuit can be prolonged for the purpose of connection to other equipment placed downstream of submersible centrifugal pump by means of this circuit transit through the downhole part of the system in order to arrange measurement and control of actuating mechanisms placed in other areas of the well space. The downhole control unit contains analogue and discreet measuring channels connected to the processor. Outputs of analogue pressure and temperature transducers and test signal shaper are connected to respective inputs of analogue multiplexor which output is connected to input of analogue-to-digital converter. Its second input/output is connected to the first input/output of the processor and the second input/output of the processor is connected to control input of multiplexor. Discreet measuring inputs are connected to vibration sensor and the third input/output is connected to the first input/output of the amplifier. Number of measured parameters is increased due to additional measuring channels and modification of the processor application software.

EFFECT: improvement of the device operational reliability and simplification of the device.

6 cl, 2 dwg

FIELD: oil and gas industry.

SUBSTANCE: bore core is selected and examined, induction logging and induced gamma-ray logging or neutron-neutron logging is made and log curves are analysed for the roof of production tier. At that formations with apparent resistivity are identified with values less than 6-8 Ohm/m during induction logging and against values at curves of induced gamma-ray logging or neutron-neutron logging making less 85% and less than values of lower formations. Among these formations it is necessary to select strata without loamy lintels and strata of carbonate oil-filled formations and values of apparent resistivity not less than 15 Ohm/m against data of induction logging. Then sedimentary types for the selected formations is defined and if oil-saturated sandstone is present then conclusion is made about terrigenous origin of these formations. Then values are specified for porosity coefficient, permeability and oil-saturation coefficients and when lower limits for this region are exceeded the indentified formations will be referred to productive formations.

EFFECT: increase of operational efficiency during installation of the bottom-hole complex, improvement of level of detail and authenticity of GIS data for identification of geological rating for rock masses.

1 tbl

FIELD: oil and gas industry.

SUBSTANCE: down-hole testing and measuring complex includes earth control station with telemetric data system connected by a logging cable with submerged-type electric pump at the end of tubing string, system of measuring modules including sensors for recording of parameters (yield, pressure, temperature, moisture content) and driving machine for their delivery to horizontal section of a well connected by a logging cable that provides rigid mounting for the system of measuring modules and transfer of data to the control station. Logging cables of the system of measuring modules telemetric system unit are connected by cable connectors. Driving machine contains two walking modules connected electrically and further driven by electrical micro-drives and sequential movement of wedged supports. Installation of the down-hole testing and measuring complex is performed in two stages. At first system of measuring modules is lowered to a well by means of winch with survey cable connected by a cable connector with a logging cable of the system of measuring modules passing through a groove in the wall of an installation pipe mounted at the well surface at the end of tubing string and by the other butt end - to the deadman in which tube there is a movable logging cable. The system of measuring modules is lowered at first up to driving machine turning to a relatively horizontal section, then by means of the driving machine it is hold to the relatively horizontal section until cable connector seats in the deadman tube; the latter is lowered by means of the installation pipe to the preset depth and fixed on the well bore. Thereafter power supply is switched odd in the micro-drive, by means of the winch socket with the survey cable is disconnected from connector pin and the installation pipe is lifted to the surface. At the second stage submerged-type electric pump is lowered to the well with logging cable and socket of cable connector contact pair filled by liquid sealant which is by means of a centring skid connected to the logging cable for the system of measuring modules.

EFFECT: increase of operational efficiency during installation of the bottom-hole complex.

6 cl, 5 dwg

FIELD: oil and gas industry.

SUBSTANCE: down-hole testing and measuring complex includes earth control station with telemetric data system connected by a logging cable with submerged-type electric pump at the end of tubing string, system of measuring modules including sensors for recording of parameters (yield, pressure, temperature, moisture content) and driving machine for their delivery to horizontal section of a well connected by a logging cable that provides rigid mounting for the system of measuring modules and transfer of data to the control station. Logging cables of the system of measuring modules telemetric system unit are connected by cable connectors. Driving machine contains two walking modules connected electrically and further driven by electrical micro-drives and sequential movement of wedged supports. Installation of the down-hole testing and measuring complex is performed in two stages. At first system of measuring modules is lowered to a well by means of winch with survey cable connected by a cable connector with a logging cable of the system of measuring modules passing through a groove in the wall of an installation pipe mounted at the well surface at the end of tubing string and by the other butt end - to the deadman in which tube there is a movable logging cable. The system of measuring modules is lowered at first up to driving machine turning to a relatively horizontal section, then by means of the driving machine it is hold to the relatively horizontal section until cable connector seats in the deadman tube; the latter is lowered by means of the installation pipe to the preset depth and fixed on the well bore. Thereafter power supply is switched odd in the micro-drive, by means of the winch socket with the survey cable is disconnected from connector pin and the installation pipe is lifted to the surface. At the second stage submerged-type electric pump is lowered to the well with logging cable and socket of cable connector contact pair filled by liquid sealant which is by means of a centring skid connected to the logging cable for the system of measuring modules.

EFFECT: increase of operational efficiency during installation of the bottom-hole complex.

6 cl, 5 dwg

FIELD: radio engineering, communication.

SUBSTANCE: disclosed is a method of transmitting measurement data by a cable-free telemetric system when drilling wells, involving encoding and transmitting information via a phase-shift keyed signal in form of a sequence of pulses, synchronising the signal and receiving the encoded information by a land receiver. One-time (initial) phase synchronisation of precision quartz-crystal oscillators of the transmitter of the bottom telemetric system and the land receiver is carried out by accumulating data on the transitioning of the signal through zero and one-time synchronisation of signals using a priori information on the bottom telemetric system at the current moment in time is also carried out. Prolonged stability of synchronisation of said oscillators is ensured by adjusting the phase of the quartz-crystal oscillator of the land receiver relative to the statistically determined transitioning through zero of the signal of the transmitter of the bottom telemetric system.

EFFECT: higher capacity of the communication channel and high noise-immunity thereof.

1 dwg

FIELD: oil and gas industry.

SUBSTANCE: method involves drilling of a well accompanied by mud logging. At that in drilling process total content of hydrocarbon gas and luminescent properties of capillary extraction are determined. Moreover if total content of hydrocarbon gas is 2% and more and luminescent properties of capillary extraction are equal to 2 points and more the penetrated stratum is subject to further surveys. Packed-hole assembly is pulled out from the well, flow string with packer is lowered and the packer is located over the penetrated stratum; circulation of flush liquid is arranged, tubular annulus is filled with a tracing fluid, the packer is inserted into the borehole over the penetrated stratum. The flow string is swabbed with the rate of 10-17 m/min till intake of reservoir fluid is obtained. In swabbing process samples of liquid are taken to check oil presence. When oil is received from the stratum its daily production rate is determined by build-up method from the maximum reduction value for the level, but not less than 3 MPa of bottomhole pressure. Conclusion on productivity of the penetrated stratum is made provided that oil flow rate is 2 m3/day and more. Drilling of the well is continued.

EFFECT: increase of reliability and operational efficiency, determination of productivity in the process of well drilling.

FIELD: oil and gas industry.

SUBSTANCE: method involves three stages: acquisition and processing of borehole data, sending and transfer of signals, and acquisition of data on the surface. Into a drilling string there can be installed a relay system for recovery of signals. By means of a connecting element between a piezoelectric converter and a drilling pipe and by means of transfer ability of wave of stresses of the drilling string, by detection there automatically chosen is an optimum frequency and used for transfer of signals to the surface through the drilling string. In order to transfer signals, detection of a chaos generator is used, as well as in order to solve a Duffing equation, Runge-Kutta method of the fourth order is used to determine availability of a signal as per the value of the system period, and then, a useful signal is picked up. The system comprises a system for the well data receiving and sending, and a system for data acquisition on surface, as well as it can include a relay system. Signals can be transferred in two directions.

EFFECT: invention can be widely used at drilling using liquid or gaseous fluids; its advantage comprises high data transfer and detection rate.

8 cl, 2 dwg

FIELD: oil and gas industry.

SUBSTANCE: method involves thermometry and gamma logging of a well with recording of a background value of natural radioactivity of rocks and background distribution of temperature along the well shaft, a disturbing action, repeated telemetry and gamma logging with recording of values and data of a flow meter, and comparison of data. Thermometry and gamma logging is performed via inter-tube space of the well; the disturbing action is taken by reduction of liquid level in the well by pumping of inert gas to the inter-tube space at the pressure not exceeding maximum allowable pressure on a production string, with displacement of liquid to a tubing string through valves of a rod well pump and then to a discharge line by excess pressure bleeding-off to atmospheric pressure. At repeated performance of thermometry and gamma logging, a geophysical instrument is lifted by 50-100 m higher than the roof of upper perforation interval at the speed of 180-200 m/h with simultaneous recording of a liquid flow rate with a borehole thermoconductive flow meter, intensity of gamma emission of rocks and temperature; after the above instrument passes the distance of 50-100 m above the roof of upper perforation interval, recording is performed only with a thermometer at the speed of 400-600 m/h; when temperature anomalies are found out, which differ from temperature values at test recording via the well shaft, the data of intervals is specified and detailed by performing complex recording using the borehole thermoconductive flow meter and a mechanical flow meter at the speed of 180-200 m/h with measurement of 30-40 points at the investigated interval; after recording via the whole well shaft is completed, repeated lowering of the instrument, repeated temperature recording is performed; complex recording is performed using the borehole thermoconductive flow meter and the mechanical flow meter with measurement of 30-40 points; after the borehole working face is reached, the geophysical instrument is lifted, during which the same records are taken with a thermometer, the borehole thermoconductive flow meter and the mechanical flow meter as at the repeated lowering operation.

EFFECT: surveying of a production well with a lowered non-operating bottom-hole pump.

FIELD: oil and gas industry.

SUBSTANCE: bottomhole drilling fluid flow rate sensor includes a housing, a diaphragm and connecting tubes. At that, the device located in lower part of a drill pipe immediately above a bit and rigidly fixed on the pipe walls has a mechanical oscillating system made in the form of a hollow counterweight with a membrane, which is torsionally suspended on two capillaries, and with a constant magnet fixed on it, a system of actuation and pickup of oscillations, which interacts with a constant magnet field, and two separating vessels interconnected with the capillaries. Fluorocarbon liquid "Б"-1 serves as separating liquid for space under the membrane of the counterweight, and dibutyl phthalate - for space above the membrane.

EFFECT: improving reliability of measurement of the drilling fluid flow rate immediately during well drilling process.

1 dwg

FIELD: oil and gas industry.

SUBSTANCE: method involves drilling of a horizontal well with a descending working face to the formation bottom, injection of displacement agent and extraction of the product. According to the invention, investigation of the well is performed, level of oil-water contact (OWC) is determined; after that, an ascending shaft to the formation roof is drilled out of the horizontal well at the distance of 150-500 m from the descending section. Secondary drilling of the formation is performed below OWC level in the descending section and above OWC level in the ascending shaft. The ascending shaft between the horizontal wall and the opening is equipped with a packer with a valve passing the product of the formation to the horizontal well, and the horizontal well between the descending section and the ascending shaft is equipped with an additional packer with a spring-loaded valve passing the liquid from the horizontal shaft to the opening of the descending section at the pressure exceeding hydrostatic pressure in the well. After that, a pump is lowered on tubing to the well, by means of which the product of the formation is extracted from the ascending shaft above OWC level. At reduction of formation pressure the pump recovery of the formation product is stopped, and displacement agent is pumped via inter-tube space through the descending section and the spring-loaded valve of the additional packer to the formation below OWC level to maintain formation pressure. Then pumping is stopped, and the pump recovery of the product is continued. When necessary, pumping cycles of displacement agent are repeated.

EFFECT: improving coverage efficiency of formations by production as to surface area and as to the section, well flow rates, additional oil recovery, improving oil recovery of formations and maintaining optimum formation pressure.

2 cl, 1 ex, 1 dwg

FIELD: oil and gas industry.

SUBSTANCE: method involves separation of formations in a well with a packer, pumping of liquid to each formation via its pipe string, interruption of pumping to both formations, continuation of pumping to the formation with high permeability and continuation of pumping to both formations. Strings at the well head are connected with a disengaged connection strap. First, maximum allowable requirements for pressure and intake capacity for low-permeability formation are determined. Interruption of pumping is performed after reduction of intake capacity and rise of pressure at the head of the pipe string interconnected with the formation with low intake capacity to maximum allowable requirements. Pumping to the formation with high intake capacity is performed owing to liquid flowing from the formation with low intake capacity via pipe strings through the connection strap till the wellhead pressure is equalised; after that, liquid residues are removed from the formation with low intake capacity to a movable tank in the near-wellhead zone.

EFFECT: possibility of restoring the intake capacity of the formation with low intake capacity without underground repair and overhaul of the well; excluding contamination of the water passage led to an injection well from a cluster pumping house with the contaminants escaping the bottom-hole zone of the formation.

1 dwg

FIELD: oil and gas industry.

SUBSTANCE: method involves arrangement of production and injection wells, pumping of displacement liquid through injection wells and extraction of the product through production wells. According to the invention, the first injection well is developed for pumping of displacement liquid with development of interval of oil-water contact (OWC) of the formation. Extraction of the product is performed from production wells with developed oil-saturated intervals of the formation, which envelop it. To the first injection well there performed is cyclic pumping of displacement liquid with 400-500% of compensation of product extraction from production wells enveloping it. After flooding in fractures of one of production wells enveloping the first injection well, isolation of the developed oil-saturated interval of the formation in the same well is performed with development in it of interval of OWC of the formation and with its being changed over to the second injection well for pumping of displacement liquid with 400-500% compensation of the product extraction from production wells enveloping it after flooding in fractures of one of the production wells enveloping the second injection well. Isolation of oil-saturated interval of the formation is performed in the same well with development in it of OWC interval and with its change-over to the third injection well. Gradually, as fractures are being developed, a row of injection wells is created on the oil deposit, to which displacement liquid is pumped. After flooding for 70-80% of production wells enveloping each of the injection wells, that injection well is changed over to extraction of the product after the development interval is changed from OWC to oil-saturated interval of the formation.

EFFECT: increasing the efficiency of the method.

3 ex, 3 dwg

FIELD: oil and gas industry.

SUBSTANCE: proposed method is based on a periodic injection of a working agent to injection wells, and namely to some part of production wells at late development stage of a deposit by converting them to injection wells. According to the invention, injection of the working agent is performed at gradual pressure rise (during several months) excluding its penetration into neighbouring wells and till the value that exceeds by two times the formation pressure by the moment when production wells are converted to injection wells. After the volume of the pumped working agent becomes equal to volume of the fluid removed from the production well for the whole development period before the production wells are converted to injection wells, injection of the working agent to injection wells is stopped abruptly from the condition of closure of fractures of the deposit formations. Off-spec water formed during operation of production wells is used as a working agent.

EFFECT: increasing oil recovery of production wells on the deposit.

1 ex, 4 dwg

FIELD: oil and gas industry.

SUBSTANCE: in the course of deposit development there performed is the pumping of working medium into injection accepting wells by cross-well pumping of produced water from well-donor and extraction of product from production wells. There analysed are the development conditions and possibility of simultaneous stopping of one or several accepting wells and/or changing of working medium pumping modes into accepting wells depending upon development requirements. Electric centrifugal pump in well-donor is replaced by pump of larger capacity with frequency-regulated drive considering the provision of working medium supply without breaking out into accepting wells in normal mode as well as in varying mode at stopping of one or several accepting wells and/or changing of working medium pumping modes into accepting wells depending upon development requirements. Electric current frequency for feeding newly installed pump is reduced and increased depending upon the varying mode.

EFFECT: increase of stability of injection wells operation and possibility to control their work depending upon development conditions.

1 ex

FIELD: oil and gas industry.

SUBSTANCE: method involves in-line drilling of injection and production wells, pumping of displacement working agent through injection wells and extraction of oil through production wells. At the first stage, wells of injection rows and the first rows of production wells, which are the closest to them, are drilled in pairs and brought into operation. At the second stage, the second rows of production wells, which are the closest to the first rows of production wells, are drilled in pairs and brought into operation. At the last stage, a tightening central row of production wells is drilled and brought into operation. Besides, wells of injection rows are developed in "next but one" manner for injection at the first stage. At the second stage, after oil development, the rest wells of injection rows are developed for injection. All production wells of the first production rows and next but one of the second production rows are subject to formation hydraulic fracturing - FHF. At the last stage, production wells forming transverse rows after their oil development are developed for injection. Production wells of tightening central row are drilled in the form of horizontal and/or horizontally branched wells with reduction of the number of planned wells of that row by 3 times.

EFFECT: possibility of complete and uniform development of oil reserves as to the deposit area; increasing oil extraction coefficient.

2 dwg

FIELD: oil and gas industry.

SUBSTANCE: according to the method lens and productive formation below lens are opened with a single well. A set of geologic-geophysical, hydrodynamic, core, fluidal PVT surveys is performed, in particular, borders are determined and lens profile is analysed. 3D geologic and 3D hydrodynamic models of oil-saturated lens and productive formation below it are created. 3D hydrodynamic model is adapted to results of all the surveys. Perforation holes are made in the central part of lens, through which by means of forcing of easily filtering plugging composition a barrier is formed preventing premature flooding of well and increasing of lens volumetric efficiency by forcing out. Well is perforated in lens bottom part and in interval of productive formation to provide overflow of fluid influx from productive formation to bottom part of lens. Well is perforated in roof part of lens to provide product removal. Intervals of well perforation in bottom and roof parts of lens are separated, then product is removed in water-pressure mode provided by productive formation located below.

EFFECT: increasing oil removal coefficient at minimum costs.

4 cl, 3 dwg

FIELD: oil and gas industry.

SUBSTANCE: according to the proposed method, productive formation is developed by drilling a pilot borehole with a zenith angle at the interval of 80°-95°; cutting-out means are arranged in the pilot borehole with possibility of increasing the zenith angle in order to reach the horizontal section during the drilling process; production casing is lowered and geophysical surveys are performed; and horizontal boreholes are drilled out of the pilot borehole in productive formation. Prior to the drilling process, predominant direction of cracks of natural fracturing is determined in productive formation and width of increased fracturing zone is estimated as per the data of geophysical surveys. Horizontal boreholes are arranged mainly perpendicular to direction of fracturing zone with an offset of mine faces from each other through the distance of not less than 40 m. A drilling passage is individually determined for each horizontal borehole; drilling roof of the drilling passage is restricted with productive formation roof, and bottom of drilling passage is assigned at the distance from the roof of not more than 1/2 of productive formation thickness and not less than 2 m to oil-water contact. Productive formation inlet point is assigned by determining the technical capability of increasing the borehole curvature. Length of pilot borehole from inlet point to the supposed zone of increased fracturing is chosen so that provision is made for possible drilling of the second and the third boreholes with azimuth entry to increased fracturing zone with an angle at the interval of 80°-95° and with an offset from pilot borehole of not less than 40 m. As per results of pilot borehole drilling in zone of increased fracturing, width of that zone is determined. Length of pilot borehole is restricted by passage of increased fracturing zone. Based on geological connection to pilot borehole, drilling of the second borehole is performed at the distance providing the possibility of opening the increased fracturing zone in the roof part of drilling passage, with entry to increased fracturing zone with zenith angle of 80°-95°, with an offset from pilot borehole of not less than 40 m, with passage of increased fracturing zone in roof part of drilling passage and with an offset from pilot borehole of not less than 40 m. Drilling of the third borehole is performed on the opposite side of the pilot borehole relative to the second borehole at the distance providing the possibility of opening the increased fracturing zone in the bottom part of drilling passage, with entry to increased fracturing zone with zenith angle of 80°-95°, with an offset from pilot borehole of not less than 40 m, with passage of increased fracturing zone in bottom part of drilling passage and with an offset from pilot borehole of not less than 40 m. Formation product is extracted through the drilled well.

EFFECT: increasing oil recovery of deposit.

2 ex, 1 dwg

FIELD: oil and gas industry.

SUBSTANCE: according to the method, when multiformation oil deposit is being developed, oil is extracted through production wells from lower productive horizon, working fluid is pumped to lower productive horizon, oil is extracted through production wells from upper productive horizon and well pattern of upper horizon is packed. Oil extraction through production wells from upper productive horizon is performed till formation pressure is decreased by 10-40%; when well pattern is being packed on injection wells operating for lower horizon, perforation at the upper horizon interval is performed. Separate pumping of working fluid is performed simultaneously to lower and upper horizons. When pumping is being performed to upper horizon, the pumping volume is preset, which is equal to the required compensation volume in the section, and the influence is observed as per responding production wells. In case of the influence confirmed with the rise of current bottomhole pressure in production wells of not less than 10%, the flow rate pumping is restricted for the injection well by 20-80% of the initial one, and the extraction is intensified for the responding production wells.

EFFECT: improving oil recovery of the deposit.

1 ex

FIELD: oil and gas industry.

SUBSTANCE: according to the method, when oil deposit is being developed, working fluid is pumped through injection wells and product is extracted through vertical and horizontal production wells with an uprising shaft. Horizontal wells with the uprising shaft are made of one cluster in the form of a fan; lower part of each well is arranged at the distance of 7-10 m above the boundary between oil saturation zone and residual oil saturation; wells are made with an open shaft in productive formation zone.

EFFECT: increasing oil recovery of deposit.

1 ex, 2 dwg

FIELD: oil and gas production.

SUBSTANCE: groups of high intake- and low intake-capacity injecting wells are chosen in a single hydrodynamic system and, for each well, oil reservoir properties and permissible degree of pollution of fluid received by high intake-capacity wells are determined. When fluid from low-permeable oil reservoir flows off through high intake-capacity wells, this fluid is cleaned to permissible degree of pollution.

EFFECT: reduced losses in intake capacity of formations and increased time between treatments of wells.

1 dwg

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