Method for producing formations with hard to recover hydrocarbon reserves

FIELD: oil and gas industry.

SUBSTANCE: according to the method the length of the won formation areas between the pairs of wellholes and the formation of technological lines of the formation parameter functions and fluids is predetermined byinclinometry data. Hydraulic fracturing of the formation is carried out between the pairs of wellholes forming the direct and crossing output channels. Gamma- and neutron logging are carried out while studying the well perforation zones. Continuous research of fractured areas under nominal and maximum operating pressures when pumping batches of marks is performed. The number of well plugging points in static characteristic function of the generating channels parameters is determined. The research of factures is finished and interfracture areas are plugged in the range of pressures between the pressures of hydraulic fracturing and operation before the second output channel occurs. Redefined research mode is installed. The number of well plugging points in dynamic characteristic function of output channels is specified and the underlying flows considering front coordinates of the formation water cut are described. Preliminary studies are carried out, when the movement of fluids to the front of the water cut in the tenth part of the output channel length can be described by Boussinesq approximation, and after him - by Dupuis-Forchheimer correlation. Similarly, research refinement is carried out when Poiseuille expression is used in the middle of the length of the output channel before the water cut. Research refinement mode is installed using the analytical expression of Dupuis-Forchheimer. Wherein, delivery of the marks and plugging materials express the dependence of Poiseuille to complete formation output. Interfracture areas are plugged due to permanence of output channels cross-section profiles. During high-viscosity fluids, delivery of marks and plugging materials with solvents in the interfracture intervals is confirmed by increased oil content in the output well. Poisson's ratio is used to describe the motion of fluids. Oil extraction starts from the crossing seam output channels.

EFFECT: intensification of production and increasing coefficient of the production extraction from formation due to increasing the fromation coverage by filtration.

5 cl, 2 tbl, 5 dwg

 



 

Same patents:

FIELD: oil and gas industry.

SUBSTANCE: invention relates to the oil industry and may be used in the operation of a horizontal well. According to the method well operation is performed. A pipe string is run down to the horizontal well. An insulating material is injected through the pipe string to a water-inflow interval of the productive formation. Oil is extracted until the horizontal well is flooded. Under the main borehole along the boundary of the oil-water contact an additional borehole is drilled from the horizontal well per 50 m longer than the old hole. The coil tubing is run down to the well complete from below with a hydraulic whipstock and a screen, which openings are covered hermetically by a hollow bushing. The process fluid is injected to the coil tubing thus creating an excess pressure. Simultaneously the coil tubing is moved down until it gets to the additional borehole. The coil tubing is run down up to the bottomhole of the additional hole. At the wellhead a top cementing plug is set into the coil tubing. An excess pressure is created in the coil tubing above the top cementing plug and the hollow bushing is moved thus opening the screen openings. Microcement grout is injected through the coil tubing and flushed to the additional hole and the bottomhole zone. Simultaneously the coil tubing is pulled out for the purpose of additional hole filling with the microcement grout. Flushing of the microcement grout is stopped when pressure increases in the coil tubing up to a permissible value. The coil tubing is pulled out from the well and the process is withheld for cement setting and hardening. The additional hole is cut off from the old hole by setting a bridge plug in a kickoff interval at the inlet to the offshoot. A pump is run down at the process pipe string to the old hole of the horizontal well and operation of the horizontal well is started. At water encroachment into the produced product the process pipe string with the pump is pulled out from the well, a geophysical study is performed and a water-producing interval is indentified in the horizontal well. The water-producing interval in the old hole of the horizontal well is isolated.

EFFECT: increased efficiency of the method due to the complete exhaustion of oil reserves from the productive formation notwithstanding the drawdown value.

4 dwg

FIELD: oil and gas industry.

SUBSTANCE: according to method of development of oil well containing oil-bearing stratum and underlying water-bearing stratum divided by bulkhead having thickness of 0.8-2m the well is surveyed in order to identify position of oil-bearing and water-bearing stratum strata. State of the flow string is defined. Behind-the-casing-flows are identified. Inflow and injection profiles are defined. Then water-bearing stratum is perforated. A packer is run down to the upper boundary of water-bearing stratum and set. Then water shutoff compound is injected and flushed to water-bearing stratum in volume precalculated as per analytic expression. Water shutoff screen is formed. Then the packer is pulled out. Cement grout is pumped to the flow string up to the level higher than roof of oil-bearing stratum until it forms a cement plug insulating the stratum. Upon waiting period for cement hardening the cement plug is drilled out up to the depth higher than roof of water-bearing stratum. At that minimum waiting period for cement hardening is equal to 24-72 hours. Tightness of the bottom hole is surveyed. The oil-bearing stratum is penetrated within the required interval and oil is recovered.

EFFECT: reduced probability of behind-the-casing flows in underlying water-bearing strata, increasing oil flow rate and reducing water encroachment in oil.

2 cl, 1 tbl, 1 dwg

FIELD: oil and gas industry.

SUBSTANCE: water and gas influx limiting method with well productivity recovery includes running in of a perforator at the flow string, perforation of the production casing, isolation of water and gas influx and elimination of leak-tightness failures in the production casing by injection of isolating compound through new openings thus forming a water-shutoff screen. At that perforation of the production casing and injection of the isolating compound are carried out during one trip of the perforator. A hydromechanical perforator designed to make openings in the production casing and further injection of the isolating compound is used as a perforator. At that perforation of the production casing is made within the interval of water and gas inflows.

EFFECT: providing reliable recovery of productivity and injection capacity of wells, improving efficiency of stratal water isolation, reducing quantity of round-trip operations.

3 cl

FIELD: oil and gas industry.

SUBSTANCE: method includes the conducting of repair and insulating works, "moderate" perforation of the production casing by a power drill with the working member equipped with hydromonitor channels, injection of sealing composition into the punched holes, bridge installation inside the production casing and subsequent re-perforation and development of the productive formation. Meanwhile during a single tripping of the perforator "moderate" perforation of the production casing is made in the interval below the productive formation and above the water producing formation. A simultaneous sealing of the formed holes of the interval and the bridge installation inside the production casing by means of supply of cementing composition through the perforator are performed. The perforator is backwashed when it is lifted to the productive formation, which is re-perforated and developed by the same perforator.

EFFECT: saving of time and resources for the method implementation at the expense of execution of several actions in one tripping.

FIELD: oil and gas industry.

SUBSTANCE: method includes running in of a flexible coiled tubing, filling of the well with blocking fluid in the interval from the bottomhole up to the lower part of water influx closest to the bottomhole. Water-shutoff compound is injected and flushed to the producing formation with simultaneous running out of the flexible coiled tubing up to the upper part of water influx closest to the bottomhole. At that the rate of the well horizontal section should be several times more than the rate of the flexible coiled tubing movement in order to ensure even placement of water-shutoff compound in the producing formation. The well horizontal section is filled with blocking fluid up to the next water influx shutoff interval and isolation works are performed in sequence at each influx interval starting from the interval closest to the bottomhole. Upon isolation of the last water influx the well is closed under pressure for reaction of water shutoff elements and destruction of the blocking fluid. Thereafter the flexible tubing is run in up to the bottomhole and the well is washed in volume of at least 2 circulation cycles.

EFFECT: increased shutoff efficiency of brine water influx in horizontal wells both with cased bottomhole and open bottmhole with a slotted liner or without it.

6 dwg

FIELD: oil and gas industry.

SUBSTANCE: invention is related to oil and gas industry, and namely to shutoff of stratal water influx in gas and gas condensate wells by means of coil tubing technique. The concept of the invention is as follows: the method lies in running in of a flexible pipe into inner cavity of gas-well production tubing up to the bottomhole and cleanout of the bottomhole from liquid and mechanical impurities, filling of the well with gas condensate, subsequent lifting of the flexible pipe up to tubing shoe, injection to the perforated interval through annular space between the flexible pipe and production tubing of the first package of hydrophobisated compound containing ethyl silicate ETC-40 with 10% concentration in gas condensate with volume of 1-2 m3 per each meter of gas net pay with its further flushing to the stratum and formation of water shutoff screen in the productive stratum thus pushing stratal water out from the bottomhole to the stratum depth radially. Then through annular space between the flexible pipe and production tubing injection of the second package of hydrophobisated compound is made containing ethyl silicate ETC-40 with 100% concentration in volume of 0.4-0.6 m3 per each meter of gas net pay with its further flushing to the stratum by gas condensate in the volume of production tubing and inner space of the well - production string below the tubing shoe. Then running in of a flexible pipe is repeated to the interval of gas-water contact, water-repellant organosilicon liquid GKZH-11N is injected through the flexible pipe in volume of 0.10-0.15 m3 per each meter of water-bearing thickness of the stratum, return washing of the well during 2 cycles with back pressure. The flexible pipe is removed from the well; the latter is withheld for reaction under pressure.

EFFECT: potential shutoff of stratal water influx without well killing operation and maintenance of gas net pay.

3 ex, 4 dwg

FIELD: oil and gas industry.

SUBSTANCE: according to the method the well is killed, the sand plug is washed and hydraulic fracturing of the formation is made with its simultaneous setting within the whole perforation interval. Volume of the well bottomhole zone within the perforation interval is divided into two production facilities by injecting and flushing of waterproofing compound to the formation depth radially thus forming water shutoff screen. Time is withheld for hardening of the waterproofing compound. The well volume at the water shutoff screen level is divided into two production zones by setting a packer run in with the tubing string. The tubing string is equipped with a gas lift valve in the upper part of the upper facility perforation interval. The string shoe is set at the level of 1.5-2m below the lower openings in the lower facility perforation interval and water extraction is made by intrawell gaslift from the lower production facility due to gas energy from the upper production facility.

EFFECT: improved productivity of wells due to recovery of wet gas or gas condensate wells, prevention of their further drowning and self-killing, increased life between overhauls.

3 cl, 1 ex

FIELD: oil and gas industry.

SUBSTANCE: group of inventions is related to downhole devices for instillation in the well bore in the underground area and methods of flow regulation in the well bore. Technical result lies in effective regulation of fluid flow. The downhole device for instillation in the well bore in the underground area contains the first fluid diode having the first inner surface limiting the first inner chamber and output of the first inner chamber, at that the first inner surface facilitates fluid swirling when it is directed to the output; and the second fluid diode having the second inner surface limiting the second inner chamber in fluid communication with the above output, moreover the second inner surface facilitates fluid swirling when the swirling fluid is received through the above output. In the method of flow regulation in the well bore in the underground area fluid is transferred through the first fluid diode and the second fluid diode through the channel between inner space of the downhole device and its outer space in the underground area.

EFFECT: while transferring fluid through the first and second fluid diodes fluid swirling is ensured in the first and second fluid diodes.

18 cl, 6 dwg

FIELD: oil and gas industry.

SUBSTANCE: group of inventions is related to mining engineering and may be used for regulation of fluid inflow to the well. The system contains a flowing chamber through which a multicomponent fluid passes, at that this chamber contains at least one input, one output and at least one structure spirally located in regard to the output and thus facilitating helical swirling of the multicomponent fluid flow around the output. According to another version the system contains a flowing chamber with the output, at least one structure facilitating helical swirling of the multicomponent fluid flow around the output and at least one structure preventing redirection of the multicomponent fluid flow to radial trajectory passing towards the output.

EFFECT: prevention of gas cone and/or water cone formation around the well.

24 cl, 5 dwg

FIELD: oil-and-gas industry.

SUBSTANCE: invention relates to control over flow resistance in the well. Proposed device has the surface making the chamber and including lateral and opposite end surfaces. Note here that maximum distance between opposite end surfaces is smaller than maximum length of opposite end surfaces. It has first opening in one of end surfaces and second opening in said surface, isolated from first opening. Note here that lateral surface serves to swirl the flow from second opening to circulate around first opening.

EFFECT: higher efficiency of in-well fluid resistance adjustment.

27 cl, 11 dwg

FIELD: oil and gas industry.

SUBSTANCE: according to the method a pool zone is selected with hydrodynamically related wells. Product is withdrawn from producers with production rate analysis. Displacement agent is injected to injectors, at that contour lines of wells mutual influence are defined and production rates of producers are corrected. Analysis of production rate for producers and displacement agent injection to injectors is based on detected interconnections of injectors with the respective producers against their total production rate. Real operation data is considered for the selected zones using historic data within the period from 1 up to 20 years with increment size of 1-3 months and current data for the time of optimization operations performance. By production rate control in the producers the volume of injection to the injectors is changed and redistributed considering impact of the respective producers and injectors. Total volume of injection is changed not more than per 10%. Cycles of withdrawal and pressure recovery at producers are regulated including time of cyclic forced product withdrawal during 2-3 months from producers with maintained or slightly increased water cut with further pressure recovery for these wells. At that remaining reserves are depleted using current stock of wells with increase in total production rate and decrease in total water production. Flows of fluid motion are redistributed till remaining oil reserves are depleted.

EFFECT: increasing oil recovery factor due to optimized operation modes for injectors and product withdrawal from producers.

4 dwg, 1 ex

FIELD: oil and gas industry.

SUBSTANCE: in the method for development of dome oil formation at last operational stage extraction of the product is made through producers and working fluid is injected through injectors. Local area of the deposit is selected according to difference of hypsometric depths between the producer and injector per 3 m and more. In the producer standard downhole pumping equipment is replaced by downhole pumping equipment operable on round-the-clock basis. When change in water cut per 10-15% is detected volume of extracted product is limited due to change in operation time of round-the-clock downhole pumping equipment. At that at the injector area injection is limited or the well is shut in completely. Periodic measurements are made for water cut changes in operation mode of the producer. When water cut is reduced operation is continued in elastic drive without start-up of the influencing injector. Periodic measurements of water cut and bottomhole pressure are repeated for the producer. When bottomhole pressure is reduced per 5% and more in regard to the initial measured value the injector operation is started and change in the main parameters of water cut and bottomhole pressure is controlled in the producers.

EFFECT: higher oil recovery of the deposit.

1 ex

FIELD: oil and gas industry.

SUBSTANCE: during development of multilayer oil deposit working fluid is injected through injectors with common well screen. Extraction of the reservoir product through producers is also performed with common well screen. The upper layer is developed in the mode of injection to withdrawal ratio by injection of working fluid at discharge pressure according to injectivity of the stratum. A pit is arranged close to the injector and working fluid is pumped through this pit to the injector with increased injection pressure sufficient for entry of working fluid both to the upper and lower strata. Producers are operated in the mode of permanent bottomhole pressure. Upon reaction of the producers to increased pressure of working fluid injection the development is continued in the mode of injection to withdrawal ratio by injection of working fluid. Injection to withdrawal ration is redistributed for two strata simultaneously from producers with high water cut and high bottomhole pressure to producers with low water cut and low bottomhole pressure. For this purpose at producers with increasing water cut operation time of pumping equipment is reduced at permanent bottomhole pressure. At producers with low water cut operation time of pumping equipment is increased at permanent bottomhole pressure.

EFFECT: improving oil recovery of the deposit.

1 ex

FIELD: oil and gas industry.

SUBSTANCE: according to the method geophysical survey of exploratory wells is performed by crossed dipole shear sonic imager. Oriented core is selected with further determination of directions of natural fracturing. Regional directions in maximum stress of oil-saturated rock are defined. According to findings injectors are placed along the regional directions in maximum stress. Producers are placed in between injectors thus forming developing method. Part of injectors occurred in fault zones and closer than 200m is introduced into operation as producers with their further transfer to injectors. When watering is higher than break even point and when it is required to maintain reservoir pressure at the deposit producers are transferred to injectors. Transfer of wells is made so that they form rows of injectors step by step along regional directions in maximum stress of oil-saturated rock and provide even oil displacement.

EFFECT: increased reservoir recovery due to more efficient and sound placement of well pattern within the area of oil deposit considering tectonic and geomechanic conditions of pay rocks occurring.

3 cl, 3 tbl, 8 dwg

FIELD: oil and gas industry.

SUBSTANCE: group of inventions relates to the field of oil industry and can be used for enhanced oil recovery of the reservoir in the development of water-flooded reservoirs with viscous oil and bitumen at a late stage of development. The method comprises opening the reservoir with the ability to transfer the production well into the injection one, the reservoir processing, keeping the hole without any influence, intake of oil from the reservoir. At that a system of microwave electromagnetic generators with radiation frequency of 2.5 GHz is lowered into the injection well, connected to the slot antenna using the feeder. The length of the slot antenna is selected equal to the thickness of the aquifer of the reservoir. In the mode of injection, the water injection into the reservoir is carried out with simultaneous influence on the reservoir with microwave electromagnetic field, the radiation power is determined by the time of heating of the water injected in the downhole to the desired temperature. When filling 5-10% of the volume of the pore space of the formation, the well is maintained, the well is transferred into the production well, and the liquid intake from the production well is carried out.

EFFECT: increase of the effectiveness and economical efficiency of development of water-flooded reservoirs of high-viscosity oil, intensification of oil production in water-flooded reservoirs of high-viscosity oil by increasing the coverage with influence to the reservoir with heating in the bottomhole area of the reservoir of the production wells.

2 cl, 3 dwg

FIELD: oil and gas industry.

SUBSTANCE: under this method the field is drilled according to row system with triangle grid of wells. Work agent is injected in the injection wells. Oil production is performed from production wells. At initial stage of the field development the production reservoir is presented by two horizons, if divided by central separating row of injecting wells with spacing between wells at least 300 m. Central separating row is arranged along line of maximum pay structure, the injection wells in it are made with opening by common filter of the both horizons. The closest first row of the production wells is drilled at distanced from the central row at least 500 m. Other areas of the reservoir are drilled with spacing between wells 300-400 m. After injection of the central row of the injection wells to 0.4-0.7 unit fractions of the pore volume to nearest rows of the production wells at least 90% wells of the central row are shutdown. After oil withdrawal at the entire field to 90% of initial oil productive capacity between the central separating row of the injection wells and nearest row of the production wells the sealing row of the production wells is drilled. Wells of the central row are switched to production at top horizon. During watering of the production wells of the first row to 98% they are switched to water injection.

EFFECT: increased oil recovery factor of the field.

2 ex, 2 dwg

FIELD: oil and gas industry.

SUBSTANCE: under method the first device is installed in the horizontal well. Firth fluid is injected in the first horizontal well via the first device. HCs production is ensured from the second horizontal well under the first well. Second fluid is injected to the third well shifted to side from the first and second wells to displace fluids in the reservoir to the second well. At that HC production from the second well is continued. Hydraulic connection is ensured between the first, the second and the third wells. Pressure in the first well is increased using the second fluid injected to the third well. First well is closed when its pressure is increased by the second fluid to pressure sufficient to displace HCs from the second well during HCs production.

EFFECT: increased method efficiency.

29 cl, 10 dwg

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

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 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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