Method of oil field development with horizontal wells

FIELD: oil and gas industry.

SUBSTANCE: method involves construction of horizontal producers covering the field, and horizontal injectors. Displacement agent is injected through injectors, and products are swept by producers. Horizontal production wells are arranged parallel to each other. Horizontal injector is positioned between horizontal sections parallel to them. Injection starts from bottomhole. When intake capacity of reservoirs is decreased at the bottomhole of horizontal injector to minimum profitable level, non-operating section of horizontal shaft is isolated in series in direction from the bottomhole to the beginning of horizontal injector wellbore. Horizontal producers are drilled in permeable interlayer at 3-6 m distance below the reservoir bottom and at least at 10 m distance above oil-water interface. Horizontal injector is equally spaced from horizontal sections of producers by a design pattern distance. Displacement agent is injected with reservoir pressure rise by 10-20% compared to recovery zone. After time period sufficient to recover and stabilise frontal zone of liquid injected to the reservoir, operation may return to previous intervals. Horizontal sections of producers are broached in two intervals at a distance preventing hydrodynamic connection of the wells. Products are recovered in turns. Production intervals are switched when products reach minimum profitable water cut level.

EFFECT: increased oil recovery due to stabilisation of frontal zone of liquid injected to reservoir, extended application scope of horizontal wells in various field development conditions.

6 dwg, 1 ex

 

The proposed method relates to the oil industry, in particular to the field of development of oil deposits horizontal wells.

A method of developing oil deposits (patent RU №2215130, IPC7EV 43/20, publ. 27.10.2003), including the drilling of a Deposit system vertical injection and horizontal production wells with a selection of their trajectories, the injection of the displacing fluid and oil production. The trajectory of horizontal wells is determined by the alleged connection of the vertical faces of producing wells in the row layout. Come the beginning of the horizontal wellbore in the tightening zone. The end of the barrel is placed in the extreme series of wells closest to the discharge line. Spend it with multiple autopsy deposits by entry and exit of the barrel into the reservoir. As you move the water front in the development process faces a horizontal production wells are travelling to constricting the area through the phased shutdown of the crossing intervals of the productive strata.

The disadvantage of this method is that when applied the oil produced is not complete, as when you disconnect the intervals of intersection of the productive strata, there is no possibility of re-return to their exploitation. As a result of increasing the distance �t the discharge line to a series of wells reduces the impact of the injected water, reduced reservoir pressure and, as a result, the oil production rates and volumes of produced fluids.

The closest in technical essence to the present invention is a method of development of oil deposits horizontal wells (patent RU №2474678, IPC EV 43/16, publ. 10.02.2013, bull. No. 4), including the construction of horizontal production wells, covering the reservoir, and horizontal injection wells, the injection of the displacing agent through the injection wells and selection of products producing wells. Horizontal production wells are placed parallel to each other, and from the horizontal sections sequentially in different directions in the more permeable sections of drill Dating back to the reservoir top branches. Between the horizontal sections and the horizontal sections have a horizontal injection well, the injection of which begin from the bottom. By reducing the injectivity of the reservoir on the bottom of horizontal injection wells to extremely cost-effective non-working section of the horizontal wellbore are isolated sequentially in the direction from the bottom to the beginning of the horizontal wellbore of the injection well.

The disadvantage of this method is that it does not provides the option of re-return to the operation previously isolated plots horizontal �of twala. The disadvantage is also that the sequential isolation of the horizontal wellbore of the injection well remote areas of the horizontal well bore remain without influence injected into the reservoir displacing fluid. As a result of incomplete coverage of the impact of the application of the method does not allow to align the front for the promotion of the displacing fluid through the formation, which prevents the breakthrough of the injected fluid to the perforated intervals of the horizontal production wells, and to increase the oil production wells.

Technical tasks of the proposed method are improvement of technological and economic efficiency of oil field development by increasing the enrolment ratio in production of oil and of oil recovery as a result of the front alignment of the promotion of the injected displacing agents and repeated operation of flooded areas of the horizontal wellbore.

The technical result is achieved by a method of developing oil deposits, including the construction of horizontal production wells, covering the reservoir, and horizontal injection wells, the injection of the displacing agent through the injection wells and selection of products producing wells, with horizontal production wells are placed in parallel �Ruth friend between the horizontal sections and the horizontal sections have a horizontal injection well, the injection of which begin from the bottom, while reducing the pickup of the collectors on the bottom of horizontal injection wells to extremely cost-effective non-working section of the horizontal wellbore are isolated sequentially in the direction from the bottom to the beginning of the horizontal wellbore of the injection well.

What is new is that horizontal production wells is carried out in a permeable bed below the roof of the reservoir at a distance of 3-6 m and above oil-water contact at a distance of not less than 10 m horizontal injection well built equidistant from the horizontal sections of wells at a distance of step in the project grid, the injection of the displacing agent is carried out by increase reservoir pressure by 10-20% compared with the selection zone, provide for the return to the previous intervals of operation after a sufficient time for recovery and alignment of the injected fluid in the reservoir, horizontal wells open in two intervals at a distance, precluding their hydrodynamic connection, and the selection of products is produced serially, and switching from one production interval to another is carried out until the achievement of� extremely cost-effective water production.

Fig. 1 is a diagram of the implementation of the proposed method of development of oil deposits (top view) on the site of three horizontal wells. Fig. 2 shows a section through the deposits of a-A of Fig. 1. Fig. 3 and Fig. 4 shows a section a-A horizontal producing well in Fig. 1. Fig. 5 and Fig. 6 shows a section b-b horizontal injection wells in Fig. 1.

The inventive method is carried out in the following sequence.

Oil reservoir 1 (Fig. 1, 2) razvarivat vertical wells 2-4 (Fig. 1) on a sparse grid. According to drilling and seismic studies conducted on-site field, specify the geological structure of the oil Deposit. Determine the permeability, porosity reservoirs. Produce formation pressure measurements in wells 2-4.

Choose the plot of reservoir 1 with the net pay thickness of more than 15 m First deposits at the site 1 build at least two horizontal production wells 6, 7 and between one horizontal injection well 8, which are placed parallel to each other. The number of horizontal producing wells 6, 7 on a plot of reservoir 1 is restricted by the size of the selected area, the density of the design grid, which in turn depends on the type of reservoir, reservoir rock properties (permeability, porosity) and the value of the Zap�owls of oil. At low values of permeability and porosity reservoir project mesh is compacted, for example, 400×400 m to 200 m x 200 m, the number of horizontal producing wells 6, 7 respectively and horizontal injection wells on the section 8 deposits 1 will increase.

Horizontal production wells 6, 7 is carried out in a permeable bed, and they are located below the top of the reservoir 1 (Fig. 2) at the distance a=3,0-6,0 m, and above oil-water contact (OWC) is at a distance of b=10.0 m, anhydrous increasing the period of operation of the well. A shorter distance to oil-water contact will lead to a breakthrough of bottom water to the horizontal sections of the production wells 6, 7 (Fig. 1) in the result of differences in the viscosities of oil and formation water.

Between the horizontal sections of the production wells 6, 7 build horizontal injection well 8, equidistant from the horizontal sections of wells 6, 7 at a distance l step in the project grid. The length of the horizontal injection well 8 does not exceed the length of the horizontal sections of wells 6, 7.

The casing 9 (Fig. 3, 4) horizontal wells 6, 7 (Fig. 1) open perforations 10, 11 (Fig. 3, 4) at least two intervals, at a distance c, which exclude the hydrodynamic coupling. Between these intervals bushing set packers 12 allowing proizvodyostvennye the selection of the reservoir fluid.

In horizontal sections of the production wells 6, 7 (Fig. 1) pull the column tubing 13 (Fig. 3, 4) with side holes 14. The lower end of casing string 13 is muted.

In horizontal injection wells 8 (Fig. 1) pull the tubing 16 (Fig. 5). At the end of the tubing set 16 passing packer 17 enabling interval the pumping of the displacement fluid in an injection well 8 (Fig. 1) for the purpose of maintaining reservoir pressure (e.g., in the form of a self-sealing cuff, do not let the displacing fluid from the bottom to the mouth).

Horizontal production wells 6, 7 master and puts in operation. Formation fluid begin to select from the most remote of the horizontal sections of wells 6, 7. The number of intervals of the perforations 10, 11 (Fig. 3, 4) and anadromous packers 12 depends on the length of the horizontal section and permeability of reservoir rocks reservoir 1 (Fig. 1, 2). The higher the permeability of the rocks, the bigger the distance produce perforation and rarely establish checkpoints packers 12 (Fig. 3, 4).

When you reach an extremely cost-effective water production and decreasing oil rate idle intervals 15 (Fig. 4) horizontal sections of wells 6, 7 (Fig. 1) is moved toward the horizontal wellbore to the selection place�type of fluid carried through the perforations 11 (Fig. 3, 4) of the casing 9 between the feed-through packers 12 in the second interval of the reservoir 1 (Fig. 1). Learn under the selection of each next interval of the horizontal section of wells 6, 7 with the use of tubing 13 (Fig. 3, 4) and anadromous packers 12. The use of walk-through packers 12 in tubing strings 13 allows you to switch from one production interval to another while achieving maximum cost-effective water production and return to the previous intervals of operation after a time sufficient to restore the pressure and alignment of the injected displacing fluid in the reservoir 1 (Fig. 1).

In this case the idle portions 15 (Fig. 4) isolate successively in the direction from the bottom to the beginning of the horizontal section mounted bushing packers 12 (Fig. 3, 4).

After the flooding last, furthest from the bottom of the interval 11, the tubing 13 is moved to the bottom for the selection of the first from the bottom of the horizontal interval of 10 section 15 producing wells 6, 7 (Fig. 1) through the holes 14 (Fig. 3).

Horizontal injection well 8 (Fig. 1) learn and puts in operation. Initially the pumping of displacement fluid is performed in a bottom portion 18 (Fig. 5) of the horizontal section of the injection well 8 (Fig. 1).

To maximize the impact of vitess�delivery agent on a horizontal production wells injection of the displacing agent is carried out by increase reservoir pressure by 10-20% compared with the zone of selection. This relationship is established by the results of experimental work carried out in the oil fields. As a result ensured a stable and continuous impact on the reservoir 1, the effective use of the displacing agent, the increase of flow rate and volume of products produced. By reducing throttle response of reservoir rocks on the bottom horizontal injection wells 8 and extremely cost-effective non-working area 19 (Fig. 6) the horizontal wellbore of the injection well 8 (Fig. 1) isolate successively in the direction from the bottom to the beginning of the horizontal wellbore installation of the packer-cutter 20 (Fig. 6) or cement. Then learn by injection the next interval of the horizontal section 21 of the injection well 8 (Fig. 1) using the tubing 16 (Fig. 5, 6) and the packer 22.

An example of a specific implementation

The implementation of this method consider the example plot, characteristic of massive oil deposits tournaisian tier. Oil reservoir 1 (Fig. 1, 2) razvarivat wells 2-4 (Fig. 1) on a grid of 300×300 m. According to deep well drilling 2-4 and seismic studies by 2D method, conducted on-site field, specify the geological structure of the reservoir 1, built a structural map on the roof of the tournaisian tier. Lower bound for deposits of 1 is the oil-water contact OWC) (Fig. 2).

Chose the site deposits with effective net pay thickness of 19.6 m. the Dimensions of the selected portion of deposits amounted to 840×840 meters, recoverable reserves of oil - 330 THD Determined the permeability - 0,110 μm2the porosity of 12.3%, the saturation - 80,0%. Formation pressure is equal to 10.4 MPa.

First deposits at the site 1 (Fig. 1) constructed of two horizontal production wells 6, 7 at a distance of 300 m from each other and between them at a distance of 150 m one horizontal injection well 8. Horizontal wells 6-8 placed parallel to each other in a horizontal plane. The length of the horizontal sections of wells 6-8 amounted 280-285 M.

The distance a (Fig. 2) from the roof of the reservoir 1 (Fig. 1) to the bottom of each horizontal section of the production wells 6, 7 was 6.0 and 9.2 m. Distance b (Fig. 2) from the lowest point on the horizontal sections of the production wells 6 (Fig. 1) and 7 to KSS (Fig. 2) was 12.6 and 10.4 m.

Well casing 9 (Fig. 3, 4) revealed a perforation 10, 11 in two intervals, the most remote from the beginning of the horizontal sections of wells 6, 7 (Fig. (1) 95,0 m from each other. In horizontal sections of the production wells 6, 7 lowered the column tubing 13 (Fig. 3, 4) with side holes 14, the lower end of which is plugged. Between the perforated intervals at a distance of 110 m from the bottom at�Tanavoli passing the packer 12.

In horizontal injection wells 8 (Fig. 1) pulled pump-compressor pipe (tubing) 16 (Fig. 5, 6). At a distance of 105 m from the face mounted lock packer 17.

Horizontal production wells 6, 7 (Fig. 1) mastered and put into operation. Formation fluid began to take of bottom-hole zone 15 (Fig. 3) horizontal sections of wells 6, 7 (Fig. 1). Horizontal production wells 6, 7 worked for 3 years with the oil flow rates of 12.0 and 10.6 tonnes. By the end of the fourth year of operation water cut increased to 88.0 and 91,0% and the oil production rate decreased to 1.9 and 1.2 t/day. Tubing 13 (Fig. 3, 4) horizontal production wells 6, 7 is moved toward the horizontal shaft at 98,0 m to the selection of the reservoir fluid was carried out through the holes 11 (Fig. 3, 4) of the casing, located between the feed-through packers 12 in the second interval of the horizontal section of wells 6, 7 (Fig. 1). Then he mastered under the selection of oil second interval 11 (Fig. 3, 4) of the horizontal section of wells 6, 7 (Fig. 1) using the tubing 13 (3, 4) and anadromous packers 12.

Horizontal injection well 8 (Fig. 1) mastered and put into operation simultaneously with the horizontal producing wells 6, 7. The displacing fluid were pumped into the bottom portion 18 (Fig. horizontal injection well 8 (Fig. 1).

Horizontal injection well 8 worked with the excessive surface pressure higher than the initial reservoir 10.8%. Average daily injection of the displacing agent amounted to 94.5 m3for 3.5 years she dropped to 15 m3/day, reservoir pressure at the site deposits fell by 2.8 MPa.

In the absence of a pickup in the first interval 18 (Fig. 5) of the horizontal section of the injection well 8 (Fig. 1) mastered by injection the next interval 21 (Fig. 6) horizontal section of the injection well 8 (Fig. 1) with a length of 85 m. the Broken section 19 (Fig. 6) horizontal wellbore isolated by setting the packer-cutter 20. Horizontal injection well 8 (Fig. 1) put into operation with the use of tubing 16 (Fig. 6) and the packers 20 and 22.

After 2 years of operation of the second interval of the horizontal section of producing well 6 (Fig. 1) and 2.4 years of operation of the second interval of the horizontal section of producing well 7 when the water production increases to 90.0% and reducing the oil flow rates to 2.0 and 1.6 tons per day horizontal production wells 6, 7 after the front alignment of the promotion of injected liquid in the reservoir 1 is switched to the first production interval 15 (Fig. 3).

As a result of horizontal production wells 6, 7 (Fig. 1) and horizontal discharge squag�NY 8 on the site of an oil Deposit received 1 additional oil production in the amount of 7.5% compared with the same areas of the Deposit by switching from one production interval to another when reaching the maximum cost-effective water production.

The proposed method ensures the alignment of the injected fluid into the formation, the increase of oil recovery, the expanding application of horizontal wells under different conditions of development of deposits.

Method of development of oil deposits horizontal wells, including the construction of horizontal production wells, covering the reservoir, and horizontal injection wells, the injection of the displacing agent through the injection wells and selection of products producing wells, with horizontal production wells are placed parallel to each other, between the horizontal sections and the horizontal sections have a horizontal injection well, the injection of which begin from the bottom, while reducing the pickup of the collectors on the bottom of horizontal injection wells to extremely cost-effective non-working section of the horizontal wellbore are isolated sequentially in the direction from the bottom to the beginning of the horizontal wellbore of the injection well, wherein what horizontal production wells is carried out in a permeable bed below the roof of the reservoir at a distance of 3-6 m and above oil-water contact at a distance of not less than 10 m horizontal injection well build Rav�odarennoy from horizontal sections of wells is a step away project net, the injection of the displacing agent is carried out by increase reservoir pressure by 10-20% compared with the selection zone, provide for the return to the previous intervals of operation after a sufficient time for recovery and alignment of the injected fluid in the reservoir, horizontal wells open in two intervals at a distance that exclude them from the hydrodynamic coupling, and the selection of products is produced serially, and switching from one production interval to another is performed while achieving maximum cost-effective water production.



 

Same patents:

FIELD: oil-and-gas industry.

SUBSTANCE: invention relates to the oil-producing industry, in particular to oil field development with flooding. According to the method the displacement agent is injected and oil is withdrawn through the system of injection and production wells. The flooding mode is changed during the development. The displacement agent is injected into the injection well in intensive mode. Using the surface measuring instruments that are a part of an automated process control system the change of extracted oil volume growth depending on the displacement agent injection volume growth until the moment of fast drop of the extracted oil volume is monitored in real time. Then the displacement agent injection volume after which the named drop occurred is recorded. Further injection into the injection well is performed in the volume below this pre-set value.

EFFECT: decrease of labour input of control of oil field flooding process during injection of the displacement agent into injection wells.

1 ex, 6 dwg

FIELD: oil and gas industry.

SUBSTANCE: method provides for use of the production wells. One or several wells are equipped with pump unit with possibility of discharge change. For each production well the deposit or deposits used for production are known. At wellhead of each production well the produced crude oil and oil gas are measured, as well as crude oil watercut is determined. The product wells product is delivered to the gathering header of the wells cluster. The cluster contains one or more injection wells. For each injection well the deposit or deposits used for injection are known. Injectability of the injected water and required injection pressure are determined. Compatibility of the injected water and produced water is studied. Injection is performed upon compatibility of the injected and produced waters. Coordinates of all production and injection wells of the cluster using the same deposits are determined. For each production well time of the produced product lifting is determined from suction of the pump unit to wellhead at maximum discharge. Volume of produced crude oil and oil gas is measured with interval not exceeding half of measured time of fluid lifting for the given well. At wellhead of each well the injected water pressure and its volume are measured. Injected water volume and wellhead pressure are measured with interval not exceeding half of measured time of water supply to the wellhead of each injection well before parker. For each injection well the curve of injected water pressure and volume vs. time is plotted. For each production well using the plotted volume of produced crude oil and oil gas vs. time the relationship with the injected water volume and wellhead pressure is determined, as well as distances to each injection well ensuring injection to the same deposit. For the production wells equipped with pump units with possibility of discharge change such relationships are determined at different discharge. The wells cluster is controlled based on the obtained relationships for all production wells. At that the treated water supply system for injection is made with possibility to change water volume and wellhead pressure for one or more injection wells.

EFFECT: increased efficiency of clusters well control.

2 cl, 1 dwg

FIELD: oil-and-gas industry.

SUBSTANCE: this process comprises measurement of injection well capacity, feed of products of one or several production wells for preliminary water disposal. Measured are density of green oil and gas, green oil water content are measured in the well. Here said products are divided into partially dewatered oil, gas and water. Partially dewatered oil and gas are fed in gathering main. Disposed water is fed into injection well. Compatibility of disposed water with water of seam wherefrom pumping from injection well is made is defined. If threes are compatible, injection well is equipped with the device to create water pressure sufficient for water injection into seam, for example, with electrically-driven rotary pump. Said device allows varying of feed capacity by frequency-controlled drive for said pump. It is set to minimum feed to define the compliance of disposed water quality with the seam geological properties. At poor water quality, it is directed to gathering main or, at sufficient quality, it is forced into injection well. Disposed water amount is defined. Then, device feed capacity is increased either continuously or in stepwise manner to create water pressure. It is increased unless disposed water quality satisfied the seam geological properties.

EFFECT: higher process efficiency.

3 cl, 1 dwg, 1 ex

FIELD: oil-and-gas industry.

SUBSTANCE: this device comprises hollow case with cover that has working fluid feed channels and bottom with discharge channel that features cross-section larger than that of working fluid feed channel for communication case inside with well bottom zone, moving working member that makes with said case the working chambers. Said working member is shaped to truncated ellipse fitted on the case at antifriction bearing and composed of axle with relationship between arms of top and bottom ends equal to 1:2. Aforesaid working member has the channel to communicate working chamber, antifriction bearing with the case bottom discharge channel. Nozzle is arranged under said bottom with communicating discharge channel and radial equal-cross-section area. Total cross-section area of said holes equals that of discharge channel. Cover bottom surface and bottom upper surface are composed of cylinder generatrix to allow displacement of working member top and bottom arms there over and isolation of working chambers.

EFFECT: higher efficiency of stationary pulse injection of fluid.

2 dwg

FIELD: oil-and-gas industry.

SUBSTANCE: method comprises cyclic decrease and increase of pressure in a formation by pumping of water through injection wells and oil withdrawal through production wells. Into the formation through injection wells the mineralised water is pumped periodically in the volume of 0.1-5 of pore volume of the formation and fresh water in the volume of 0.1-5 of pore volume of the formation. The transition to fresh water pumping after mineralised water pumping is performed without gradual decrease in mineralisation. The structure and concentration of salts of the pumped mineralised water are remained at the level of the formation one. The cycle of pumping of waters with different mineralisation is repeated many times. Fresh water is pumped until the moment when decrease of intake capacity of the injection well exceeds the allowable production level - critical drop of reservoir pressure in target impact areas. The mineralised water is pumped until the moment when the injection well sets to initial or close to initial operating mode which depends from the flow rate of the injected liquid and well head pressure.

EFFECT: increase of oil recovery of formations due to increase of their coverage.

2 dwg

FIELD: oil and gas industry.

SUBSTANCE: method comprises run in the production well below fluid level of the pipes string with pumps, and with filters installed at pipe ends, product recovery from top production deposit, oil and water separation in the wellbore, water injection to the bottom deposit, oil lifting to surface. Two filters are run to well on separated pipe strings. Filters are pipes with capillary holes with diameter 2 mm max, and density 50 holes/m min. One filter has hydrophobic surface with hydrophobic degree 99% min, the another filter has hydrophilic surface with hydrophilic degree 99% min. Parker is installed above the top deposit to seal the annulus. Filters are made with length not below the bottom deposit roof. Filter with hydrophilic surface is made with large length then the filter with hydrophobic surface such that the parker installed between the production string and filter with hydrophilic surface will be above the bottom deposit roof, and end of the filter with hydrophobic surface will be above this parker. The parker does not permit the fluid from the top deposit flow to the bottom deposit via the annulus. Moving from the top production deposit to the wellbore the fluid enters the annulus, where it is filtered via the capillary holes of the appropriate filters with hydrophobic and hydrophilic coatings separating to oil, that entering via the filter with hydrophobic surface in the pipes string by the pump is lifted to surface, and to water that entering via the filter with hydrophilic surface in the another pipes string by the pump is pumped in the bottom deposit.

EFFECT: increased efficiency of oil and water separation in the wellbore, increased efficiency of waterflooding and increased oil recovery of the deposit.

1 dwg

FIELD: oil and gas industry.

SUBSTANCE: method comprises run in the production well of the pipes string with filter below liquid level in well, product recovery from top deposit, oil and water separation in the wellbore, water injection to bottom deposit, oil lifting to surface. The filter is pipe in pipe, the internal pipe has hydrophilic surface with hydrophilic degree 99% min, capillary holes with diameter 2 mm min, and density 50 holes/m min. Outside pipe has hydrophobic surface with hydrophilic degree 99% min, capillary holes with diameter 2 mm max, and density 50 holes/m min. Pipes string diameter used for filter run is equal to diameter on internal filter pipe. Internal pipe has length exceeding length of outside pipe. Outside pipe is located not below the top deposit, and internal pipe - not below bottom deposit. Between the casing string and bottom of the outside pipe above the top deposit the parker is installed, ensuring fluid from top deposit ingress directly in space between the internal and outside pipes of the filter. Between the casing string and bottom of the internal pipe above the bottom deposit the parker is installed also, excluding fluid from bottom deposit ingress in space between the internal and outside pipes of the filter. Moving from top production deposit to the wellbore the fluid enters the space between the internal and outside pipes of the filter, where it is filtered via the capillary holes of the appropriate filter pipes with hydrophobic and hydrophilic coatings, separating to oil that entering in the outside pipe and then in annulus by the pump is lifted to surface, and to water that entering in the internal pipe by the pump is pumped in the bottom deposit.

EFFECT: increased efficiency of oil and water separation in the wellbore, increased efficiency of waterflooding and increased oil recovery of the deposit.

2 dwg

FIELD: oil and gas industry.

SUBSTANCE: system includes a group pumping station with a pump feeding water line with a pressure sensor, a water discharge line of the pump, a valve manifold, a system of distributing water lines downstream the pump with flow meters, shut-off and control valves, low-permeable injectors with return valves and high-permeable injectors. At that the system operates in a cyclic mode with cycles of pressure increase and decrease in the feeding water line. The high-permeable injectors are equipped with spring-operated flow controllers. At the water line feeding the pump there is a pressure controller bound with a bypass line with a flow controller and automatic gate. This gate is coupled functionally with a cluster controller. It ensures the collection of data from the flow meters and pressure sensor with the analysis of the performed task against pressure injected through the distributing water lines. The automatic gate is made so that at the r signal of the controller it provides the water flow through the bypass line in order to compensate water injection to the low-permeable injectors at the total deficiency in the injection volume to them.

EFFECT: excluding deficiency in the injection volume to the low-permeable injectors and pressure balancing in feeding water lines.

1 dwg, 1 tbl

FIELD: oil and gas industry.

SUBSTANCE: reservoir pressure maintenance system includes a water supply source, pumps, low-pressure water lines connecting the pump of the water supply source to booster pumps of injectors, which wellheads are equipped with shut-off and regulating valves. At that the low-pressure water lines are under maximum permissible pressure that exceeds the maximum permissible pressure at the input of the respective booster pump; the lines are equipped with pressure regulators. These pressure regulators ensure reduction of pressure at the input of the respective booster pump in the operation process up to a value lower that the maximum permissible pressure but not lower that the minimum permissible pressure for this pump. The pressure regulators are operating as downstream pressure controllers during limitation of the injection volume to one or several injectors or during their complete shut-down. The booster pump is designed for the input pressure as per the following formula.

EFFECT: improved reliability of the pumps operation and increase of their life between overhauls.

1 tbl, 1 dwg

FIELD: oil and gas industry.

SUBSTANCE: according to the method a deposit is drilled out by wells as per the wide well spacing pattern. Deposits are surveyed with the determination of their hypsometric depths. New wells are constructed and offshoots or horizontal offshoots are drilled from the existing wells towards the maximum oil saturation of the deposit. At that a seismic survey is performed with the determination of several oil-saturated zones in the deposit with advanced permeability and porosity both in the square area and altitude of the reservoir. Availability and position of fault lines is defined additionally. New horizontal or inclined wells are constructed as per an irregular pattern so that horizontal or inclined section of these wells passes through the selected oil-saturated zone with the maximum filtering area. Construction of offshoots or horizontal offshoots from the existing wells is made towards the closest oil-saturated zone so that they pass the maximum filtering area upon drowning of the wells or reduction of the oil flow rate below the profitable value. The offshoots or horizontal offshoots pass through the zone with the effective oil-saturated thickness of at least 10 m when water-bearing reservoirs are available in the stratum foot, or at least 4 m when the water-bearing reservoirs are not available in the stratum foot. The inclined offshoots or horizontal offshoots pass through the oil-saturated zone perpendicular or at an acute angle towards the deposit fault line at the distance that allows the prevention of fast drowning of the extracted product.

EFFECT: higher efficiency of development for a less explored oil deposit.

2 cl, 1 ex, 1 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

FIELD: oil and gas extractive industry.

SUBSTANCE: method includes construction of wells and oil and gas collection system, forcing water from water-bearing level into oil deposits, flow of oil from oil deposits into secondary deposit and following extraction of oil from secondary deposit for useful implementation. Resources of deposit are separated on basis of natural energy characteristic on screened and having rigid water-forcing mode. Deposit is operated by three well types. Of the latter flow wells connect oil deposits to secondary deposit for flowing and collection of oil in upper bed under effect from gravitation. Balancing wells connect screened deposits and secondary deposit to water-forcing level for balancing of bed pressures and preventing loss of rocks stability. Extraction wells connect secondary deposit to oil and gas collection system. Selection of bed for secondary deposit is performed from number of highly penetrable beds, having maximally allowed excess over oil deposits.

EFFECT: higher oil yield, higher effectiveness.

5 cl, 3 dwg

FIELD: oil extractive industry.

SUBSTANCE: method includes drilling of deposit according to row-wise non-even grid of wells with distance from force to extractive rows, greater than distance between extractive rows, pumping of displacing gent into force wells, extraction of product from product wells and transferring of displacing agent pumping front to extraction area. According to invention, transferring of displacing agent pumping front to extraction area is performed by drilling side horizontal shafts in all wells of force row and directed towards extractive row by beds ad zones with most remainder oil saturation level. Then among these wells are singled out, horizontal shafts of which pass along beds and areas with lesser oil saturation level. Pumping of displacing agent is restarted, and other wells are transferred to product category. These wells are operated with face pressures lower than saturation pressure until reaching 98% water saturation level. After that pumping of displacing agent is restarted along all other wells of force row. During that, rows of extractive wells are operated in normal mode.

EFFECT: higher efficiency.

1 ex

FIELD: oil industry.

SUBSTANCE: according to first variant of method, force and product wells are drilled, working agent is fed through force wells, oil is extracted through product wells, dome-like raised portions are marked out, which surpass absolute marks of bed, additional wells are positioned in these portions. Wells placement is planned at tops of dome-like raised portions even with breach of evenness of planned well mesh. After full drilling of wells mesh and in case of more accurate definition according to data of drilled wells of deposit of dome-like portions side shafts are drilled from adjacent wells towards more precisely defined tops of dome-like portions, controlling the deposit. In adjacent wells and side shafts, positioned on tops of dome-like raised portions , range of productive bed is opened between absolute mark of ceiling in this well and absolute mark, appropriate for ceiling in closest well. According to second variant of method practically analogical operations are realized as in first variant, except when absolute mark of ceiling of productive bed according to adjacent wells is lower than mark of sole of productive bed, whole bed is opened in side shafts.

EFFECT: higher efficiency.

2 cl, 2 dwg

FIELD: oil reservoir development, particularly for developing water-flooded ones.

SUBSTANCE: method involves withdrawing oil through production wells and ejecting working substance through ejection wells. To prevent water ingress from well bore into oil-saturated formation area formation is perforated in water-oil interface zone so that lower part of oil-saturation formation interval and upper part of water-flooded formation interval are penetrated. This provides oil relative permeability retention in oil-saturated formation area. To prevent formation mudding during initial perforation thereof drilling is performed in depression, balance and repression modes with pressure of not more than 3 MPa. As far as oil is depleted perforation interval is extended towards oil-saturated formation area.

EFFECT: possibility to retain oil relative permeability of oil-saturated formation area.

2 cl, 2 dwg

FIELD: oil field development, particularly for ones with nonuniform reservoirs.

SUBSTANCE: method involves drilling injection and production wells; flooding oil reservoir and extracting oil out of well; defining more exactly geologic aspects on the base of drilling results; designing and drilling additional wells with horizontal bores or drilling horizontal bores from existent wells; determining location of reservoir drive zone boundaries; calculating volume of dead oil located near drive zones; drilling horizontal bores from existent wells located near drive zones and/or new wells with horizontal bores located in above zone, wherein horizontal bores are drilled in direction perpendicular to drive zone boundaries.

EFFECT: improved oil recovery.

2 dwg, 1 ex

FIELD: oil industry.

SUBSTANCE: method includes drilling vertical product and force wells, extracting oil from product wells, forcing working agent through force wells, making side horizontal shafts in force wells, forcing working agent through side horizontal shafts of force wells. Additionally, side horizontal shafts are made in extraction wells. Oil is taken through side horizontal shafts of extractive wells. With pressure in the well, decreased for 5-10% from hydrostatic pressure, all side horizontal shafts are made by washing away rock under pressure of fluid of around 15-20 mPa. Direction of all side horizontal shafts is set to be parallel to rows of wells.

EFFECT: higher oil yield.

1 ex, 1 dwg

FIELD: oil production industry, particularly enhanced recovery methods for obtaining hydrocarbons.

SUBSTANCE: method involves drilling production and injection wells and maintaining formation pressure; performing seismic works to determine volumetric routing of natural macrocrack system with lateral and depth routing; forming production and injection macrocracks of above system; drilling wells to corresponding macrocracks and forming producing well-macrocrack systems for oil production and injection well-macrocrack for formation flooding or production well-macrocrack for oil production and system including vertical and/or horizontal multibranch wells for formation flooding or injection well-macrocrack system for formation flooding and system including vertical and/or horizontal multibranch production wells for oil production or production well-macrocrack system, injection well-macrocrack system and system including vertical and/or horizontal multibranch production and injection wells.

EFFECT: increased efficiency, oil recovery and production well injectivity, as well as increased sweep efficiency and oil recovery ratio.

1 dwg

FIELD: oil production industry, particularly oil deposit development.

SUBSTANCE: method involves pumping working agent, namely water, in two stages. The first stage is performed with the use of power pumps. The second one is carried out by means of hydraulic measuring pumps, which are used to convert injection pressure created by power pumps. If it is necessary to increase pressure in water lines used to deliver water to separate injection wells pressure is regulated in accordance with necessary water volume to be injected in wells on the base of collecting properties of oil formations in bottomhole formation zones. This is performed by providing change in pump piston diameter and stroke ratios in the first and the second sections of hydraulic measuring pumps, which are selected on the base of hydraulic resistance variation depending on water flow velocity. Parameters characterizing injection system operation are simultaneously measured and efficiency of the method and equipment operation is detected from above characteristics.

EFFECT: increased efficiency of oil bed development due to energy-saving equipment and technique usage for formation pressure maintaining.

2 cl, 2 dwg

FIELD: enhanced recovery methods for obtaining hydrocarbons.

SUBSTANCE: method involves flooding production bed through injection wells with the use of pump units. In the case of terrigenous porous productive bed flooding acoustical sound resonators with resonance frequency setting are installed in injection line. This eliminates amplitude of alternating low-frequency liquid pulsation sound generated by pump units. Method also involves providing constant compression mode in productive beds and frontal oil drive from productive bed.

EFFECT: increased operational reliability.

1 ex, 3 dwg

Up!