31results about How to "Extend the stable production period" patented technology

The invention provides a plunger used for gas well water drainage. The plunger used for the gas well water drainage comprises a center pole, the top end of the center pole is fixedly connected with a throwing and pulling fish head, the periphery of the center pole is sleeved with an outer cylinder capable of sliding up and down along the center pole, the diameter of the bottom end of the center pole is larger than or equal to the inner diameter of the bottom end of the outer cylinder, the bottom end of the center pole makes contact with the bottom end of the outer cylinder in a sealing mode, a cavity is formed by the inner surface of the outer cylinder and the outer surface of the center pole, a plurality of through holes are formed along the axial direction of the outer cylinder, and the through holes are communicated with the cavity. The plunder used for the gas well water drainage is applied to the plunder gas lift water drainage technology, the gas lift water drainage plunger has the functions that an gas flow channel closes in a well bottom or in the process of ascending with liquid, and the gas flow channel opens when reaches the well mouth or in the process of descending. The plunger gas lifting technology under the condition that a gas well is not closed is achieved, the well opening time of the gas well is increased, the stable production period of the gas well is prolonged, frequent well closing is avoided, and the operation cost is reduced.

The invention relates to a high-water-content oil reservoir residual oil diving method. The method comprises the steps of determining an oil reservoir flow field quantitative characterization method by analyzing flow field geological main control factors of different oil reservoirs, further determining an initial flow field distribution rule and mode, analyzing a dominant flow field distribution rule and mode by combining development dynamics and other oilfield development later-stage data, and finally utilizing the dominant flow field-mode to analyze the dominant flow field distribution rule and mode; adopting a dominant flow field-initial flow field difference method to find residual oil, and exploiting the residual oil. According to the high-water-content oil reservoir remaining oil diving method provided by the invention, on the basis of oil reservoir classification, the influence of reservoir heterogeneity and structural characteristics on an initial flow field is deeply analyzed, and by re-analyzing the oil reservoir flow field in the later development stage, a dominant flow field is compared with the dominant flow field. The initial flow field forms a knowledge of a region beneficial to the distribution of residual oil in the later period of development, potential residual oil is dug in a targeted manner, the utilization degree and the final recovery ratio of the out-of-control reserves of the oil reservoir are improved, the oil field yield decreasing amplitude is effectively reduced, and the final recovery ratio of the oil reservoir is obviously improved.

The invention relates to an automatic chemical feeding device and method in a foam-drainage gas recovery well. The automatic chemical feeding device mainly comprises a ground chemical storage tank, a thin pipe valve, a thin pipe, a pressure difference control valve, an oil pipe and a casing. The ground chemical storage tank, the thin pipe valve, the thin pipe and the pressure difference control valve form a chemical feeding channel, the thin pipe and the oil pipe form an annular liquid discharge channel, and the pressure difference control valve mainly comprises a chemical inlet, an upper cavity, a valve spool ball, a conical valve seat, a lower cavity, a spring and a chemical outlet. The upper end of the pressure difference control valve is stressed by chemical gravity (constant in pressure), and the lower end thereof is stressed by return pressure at bottom of the well. The more the accumulated liquid is, the higher the return pressure at the bottom of the well is and the lower the downward pressure difference stressed on the valve spool ball is, so that the spring can overcome the pressure difference to support the valve spool ball upwards and chemicals are begun to be added. After the accumulated liquid is discharged, the pressure difference is larger than elastic force of the spring and presses the valve spool ball to stop chemical feeding. The automatic chemical feeding device can automatically feed and stop feeding chemicals according to level of the accumulated liquid, and the chemicals and the accumulated liquid at the bottom can be guaranteed to be sufficiently mixed.

The invention discloses a fracturing method for increasing the full-scale crack supporting volume of deep shale gas. The method comprises the steps of (1) key reservoir parameter evaluation, (2) geological engineering filling point selection, (3) crack parameter and fracturing construction parameter optimization, (4) acid slick water and glue solution formula optimization, (5) perforation operation, (6) acid pretreatment operation, (7) low-viscosity acid slick water injection construction, (8) small-particle-size propping agent injection, (9) variable-viscosity slick water and variable-viscosity ground cross-linked acid injection, and (10) propping agent corresponding injection corresponding to the step (9). The method can be realized in the deep shale gas reservoir fracturing process. Cracks of various scales are opened, communication and full expansion of the cracks of various scales are accelerated, the volumes of the supporting cracks of all levels are increased, the volume decreasing rate of the supporting cracks is reduced, maximization of the multi-scale crack making volume, the supporting efficiency and the supporting volume is achieved, and therefore the drainage area is enlarged, the single well yield is increased, and the stable production period is prolonged.

The invention relates to the technical field of oil and gas reservoir development, in particular to a multi-objective optimization method for reasonable well spacing of an ultra-deep reef flat-phase gas reservoir. The method is used for solving the technical problem that an optimal development well pattern in the prior art does not comprehensively take maximation of economic benefits, maximizationof recovery efficiency and implementation of several targets with certain stable production periods into account. The method comprises the following steps of establishing a multi-objective function of the reasonable well spacing of the reef flat-phase gas reservoir, establishing a constraint condition function and solving the multi-objective function according to the constraint condition function. The multi-objective function is solved by establishing the constraint condition function, and the obtained value of the multi-objective function corresponding to the optimized reasonable well spacing can meet the requirements for the maximum profit, the maximum recovery efficiency and the maximum stable production period. Therefore, the optimized reasonable well spacing can provide a valuable guiding basis for oil field exploration, and correspondingly considerable social benefits and economic benefits are obtained.

The invention provides a super-hydrophobic pre-filled gravel sand control pipe and a preparation method thereof. The super-hydrophobic pre-filled gravel sand control pipe comprises a base pipe, a super-hydrophobic sand control pipe shell and a super-hydrophobic gravel layer; the base pipe is sleeved with the super-hydrophobic sand control pipe shell, and the super-hydrophobic gravel layer is filled between the base pipe and the super-hydrophobic sand control pipe shell; and the surface of the super-hydrophobic sand control pipe shell is provided with a first super-hydrophobic coating, the super-hydrophobic gravel layer is collected by super-hydrophobic gravel, and the surfaces of the super-hydrophobic gravel are provided with second super-hydrophobic coatings. The super-hydrophobic pre-filled gravel sand control pipe can not only realize the self-cleaning function of the sand blocking medium, but also can achieve the purpose of controlling water and increasing oil in high water cut well and prolong the stable production period of oil wells.

The invention discloses a low pressure dense oil reservoir supplementary energy fracturing method. The low pressure dense oil reservoir supplementary energy fracturing method comprises the following steps that a plurality of long horizontal wells are deployed in a low pressure dense oil reservoir, long horizontal well shafts are parallel one another, the long horizontal well shafts are perpendicular to the direction of the maximum principal stress of the formation; each long horizontal well is laid through close cutting precision fracturing; through full three-dimensional fracturing software simulation, the amount of ground-entering fluid required for fracturing fractures to completely cover spaces between all long horizontal wells and spaces between sections of each long horizontal well segment is obtained; supplementary ground-entering fluid required when the formation pressure in the range of long horizontal well reaches a preset multiple of the original formation pressure is calculated; and all the long horizontal wells are fractured according to the amount of ground fluid and the supplementary ground fluid. According to the low pressure dense oil reservoir supplementary energyfracturing method, the production decline of the low-pressure dense oil reservoir can be slowed down, the stable production period is prolonged, the recovery degree is improved, and the cumulative production of a single well in a whole life cycle of a single well is increased.

The invention relates to a water plugging and fracturing method for an old high-water-content well in a low-permeability oil and gas field. The method is characterized in that a cementing truck is utilized for injecting cement paste into the stratum, then a fracturing truck is utilized for injecting high-viscosity suspension sand fluid into the stratum in low discharging capacity, an original propping agent in stratum cracks is suspended, and the cement paste is pushed to the end portions of the cracks, finally, surface active agent fracturing liquid is injected into the stratum in large discharging capacity for fracturing construction, wherein the initial setting time of the cement paste is 6-7 hours. The method can effectively avoid that in the fracturing process, due to the fact that the cracks extend without control, the water channeling and water logging phenomena occur, and achieve turnaround fracturing in the cracks without a turnaround agent, and is beneficial for improving thefracturing construction effect.

The invention comprises the preparation of a self-distribution seepage-regulation polymer and a self-distribution seepage-regulation water-controlling acidifying technology. The preparation of the regulation polymer comprises the steps of: adding 5-15 parts by mass of dimethyl diallyl ammonium chloride monomer, 2-8 parts by mass of acrylate monomer, 1-8 parts by mass of crylamide monomer, and the balance deionized water into a reaction vessel in turn; stirring the mixture; keeping the mixture at a constant temperature; introducing nitrogen to remove oxygen; adding a solid initiator which accounts for 0.2-0.8% by weight of the total mass; and allowing the obtained mixture to react for 7-9 hours under normal pressure. The self-distribution seepage-regulation water-controlling acidifying technology comprises the steps of preparation of a pad fluid, preparation of a cleaning agent, and performance of water-controlling acidifying construction. The preparation of the pad fluid comprises the steps of adding 0.2%-5% by weight of the self-distribution seepage-regulation polymer, 3%-15% by weight of hydrochloric acid or mud acid, and 0.5%-2% by weight of a corrosion inhibitor to clear water; and stirring the mixture uniformly under normal temperature and pressure. The preparation of the cleaning agent comprises the step of adding 2%-3% by weight of KCl brine to 20m3 of 1% by weight of a nonionic surfactant. The performance of water-controlling acidifying construction comprises the steps of washing a well in forward and reverse directions by running a tubing string; washing an oil reservoir wherein the pad fluid is injected under the pressure of less than70% of an oil reservoir fracture pressure; injecting a routine acidifying liquid and closing the well.

The invention relates to an identification method for a gas reservoir water invasion dominant channel. The identification method comprises the following steps: 1) fitting an influence parameter of a water invasion dominant channel of a target block with a gas-water leading edge propulsion speed, and screening main parameters influencing the gas-water leading edge propulsion speed; 2) calculating aweight coefficient of each main parameter by using a grey correlation method, taking the main parameter screened in the step 1) as a sub-sequence and taking a gas-water leading edge propulsion speedas a mother sequence; 3) after normalization processing is carried out on all main factors, carrying out weighted average, and calculating dominant channel factors; And 4) optimizing the dominant channel factors on each grid in combination with a geological model to obtain a dominant channel body, and determining water invasion dominant channel distribution. According to the identification methodof the gas reservoir water invasion dominant channel, subjective factors in the process of comprehensively comparing a plurality of influence factor geological models in the past are avoided, the goodness of coincidence between the dominant channel factors and dynamic data of a water-breakthrough gas well is good, and the identification precision of water invasion dominant channel distribution ishigh.

The invention discloses a preparation process of loaded water-controlled sand with phase permeability regulating function. The preparation process comprises the following steps of: A) cleaning the surface of quartz sand or ceramsite; B) modifying the surface of the quartz sand or the ceramsite; and C) mixing the surface-modified quartz sand or ceramsite and the mixture of monomer acrylic acid, propylene, sulfonated propylene and deionized water and generating the loaded water-controlled sand with phase permeability regulating function by autopolymerization under the action of an initiator. The process prevents sand; the loaded water-controlled sand with phase permeability regulating function controls water in a limited way, so that the advantages of gravel packing technology are brought into play, the conventional process technology is endowed with unique performance, sand is prevented, the comprehensive water content of an oil well is lowered greatly, the yield of crude oil is increased, the stable production period of the oil well is prolonged, development efficiency or economic benefit is improved, and the like; and the process is widely applied to a sand prevention and water control process used in oil exploitation.

The invention provides a horizontal well pre-fracturing injection fluid development method based on a three-dimensional fracturing well pattern. The method comprises the steps that 1, a target horizontal well is deployed in an oil layer, and the target horizontal well is not fractured, a first horizontal well parallel to the target horizontal well is deployed at the upper part of the horizontal section of the target horizontal well, and fracturing is carried out on the first horizontal well to form a crack perpendicular to the direction of the horizontal section of the target horizontal well,a vertical well is deployed around the target horizontal well, and fracturing is carried out on the vertical well to form another crack of which the trend is parallel to the direction of the horizontal section of the target horizontal well and the position is lower than that of the horizontal section of the target horizontal well; 2, under the condition that the target horizontal well is not fractured and does not produce, the first horizontal well and the vertical well serve as injection wells, and energy supplementing fluid is injected into a stratum; and 3, after stratum energy supplementing fluid injection is completed, fracturing is carried out on the target horizontal well, and well opening production is carried out, and meanwhile, the first horizontal well and the vertical well which sever as the injection wells are converted into oil production well for well opening production.

The invention discloses a method for controlling water and preventing sand by using a phase permeability regulator. The regulator comprises the following components in part by mass: 5 to 15 parts of acrylic acid, 2 to 8 parts of propylene, 1 to 8 parts of sulfonated propylene and the balance of deionized water. The preparation process comprises the following steps of: a, adding the acrylic acid monomer, the propylene, the sulfonated propylene and the deionized water into a reaction kettle in turn, and stirring the mixture uniformly; b, heating the mixture to the constant temperature of 90 DEG C; c, introducing nitrogen and stirring for 30 minutes, and removing oxygen from the solution; and d, adding 0.2 to 0.8 mass percent of solid initiator to initiate polymerization reaction of the solution for 7 to 9 hours under normal pressure to obtain a target product, wherein the molecular weight of the target product is 7 million to 10 million. The method for controlling water and preventing sand comprises that quartz sand carried by sand carrying fluid is injected into a target layer. The sand carrying fluid is phase permeability regulating sand carrying fluid compounded by using the phase permeability regulator and a swelling prevention agent, and 0.2 to 5 weight percent of phase permeability regulator and 0.5 to 3 weight percent of swelling prevention agent are added into every ten tons of water and stirred uniformly at normal temperature under normal pressure to form the sand carrying fluid.

The invention discloses a preparation process of loaded water-controlled sand with phase permeability regulating function. The preparation process comprises the following steps of: A) cleaning the surface of quartz sand or ceramsite; B) modifying the surface of the quartz sand or the ceramsite; and C) mixing the surface-modified quartz sand or ceramsite and the mixture of monomer acrylic acid, propylene, sulfonated propylene and deionized water and generating the loaded water-controlled sand with phase permeability regulating function by autopolymerization under the action of an initiator. The process prevents sand; the loaded water-controlled sand with phase permeability regulating function controls water in a limited way, so that the advantages of gravel packing technology are brought into play, the conventional process technology is endowed with unique performance, sand is prevented, the comprehensive water content of an oil well is lowered greatly, the yield of crude oil is increased, the stable production period of the oil well is prolonged, development efficiency or economic benefit is improved, and the like; and the process is widely applied to a sand prevention and water control process used in oil exploitation.

The invention relates to a low-permeability horizontal well identical-well injection-production technique pipe column. The pipe column comprises an oil pipe column, a pump, a bridge packer A, a bridge packer B, an inner pipe, a bridge dividing valve and an injection allocator; and the pipe is characterized in that the pump, the bridge packer A, the bridge dividing valve, the bridge packer B and the injection allocator are arranged and connected at an oil pipe in sequence; the inner pipe is arranged in the oil pipe, the middle part thereof is connected with the bridge dividing valve, and the two ends thereof are connected with the bridge packer A and the bridge packer B. The invention is characterized in that the developing cost can be reduced, the investment is less, the return is obtained quick, the construction is convenient, identical-layer injection-production distance can be regulated flexibly, the water-injection pressure loss can be reduced, the injection-production corresponding rate can be improved, the augmented-injection requirement of the low-permeability horizontal well can be met, the stabilized production period of the low-permeability horizontal well can be prolonged, and the extraction percentage of the low-permeability reservoir can be improved. Therefore, the invention is applied widely in the injection-production technique of oil production.

The invention relates to a method for water plugging and fracturing of old wells with high water content in low-permeability oil and gas fields, which is characterized in that cement slurry is injected into the formation by a cement truck, and then high-viscosity suspended sand is injected into the formation by a fracturing vehicle with a low displacement Suspend the original proppant in the formation fractures, and push the cement slurry to the end of the fracture together, and finally inject a large amount of surfactant fracturing fluid for fracturing construction. The initial setting time of the cement slurry is 6~ 7 hours. The method of the invention can effectively prevent water channeling and flooding caused by uncontrolled extension of cracks during the fracturing process, and can realize in-fracture diverting fracturing without a diverting agent, which is beneficial to improving the fracturing construction effect.

The invention discloses a low-pressure tight oil reservoir replenishment energy fracturing method, which comprises the following steps: deploying several long horizontal wells in the low-pressure tight oil reservoir, the shafts of the long horizontal wells are all parallel to each other, and the shafts of the long horizontal wells are all perpendicular to the formation The direction of the maximum principal stress; precise fracturing of each long horizontal well through dense cutting; through the full three-dimensional fracturing software simulation, the fracturing fractures can completely cover all long horizontal wells and each long horizontal well section. The amount of liquid injected into the ground; calculate the amount of additional liquid injected into the ground when the formation pressure within the range of the long horizontal well reaches the preset multiple of the original formation pressure; all long horizontal wells are fractured according to the amount of liquid injected into the ground and the amount of added ground fluid. The invention can slow down the production decline of the low-pressure tight oil reservoir, prolong the stable production period, improve the recovery degree, and increase the cumulative production of a single well in the whole life cycle of a single well.

The invention provides a plunger used for gas well water drainage. The plunger used for the gas well water drainage comprises a center pole, the top end of the center pole is fixedly connected with a throwing and pulling fish head, the periphery of the center pole is sleeved with an outer cylinder capable of sliding up and down along the center pole, the diameter of the bottom end of the center pole is larger than or equal to the inner diameter of the bottom end of the outer cylinder, the bottom end of the center pole makes contact with the bottom end of the outer cylinder in a sealing mode, a cavity is formed by the inner surface of the outer cylinder and the outer surface of the center pole, a plurality of through holes are formed along the axial direction of the outer cylinder, and the through holes are communicated with the cavity. The plunder used for the gas well water drainage is applied to the plunder gas lift water drainage technology, the gas lift water drainage plunger has the functions that an gas flow channel closes in a well bottom or in the process of ascending with liquid, and the gas flow channel opens when reaches the well mouth or in the process of descending. The plunger gas lifting technology under the condition that a gas well is not closed is achieved, the well opening time of the gas well is increased, the stable production period of the gas well is prolonged, frequent well closing is avoided, and the operation cost is reduced.

The invention provides a method for classifying low-permeability lithologic non-homogeneous gas reservoir development blocks. Multi-factor subclassification of M gas reservoir development blocks is carried out by integrating geological and gas reservoir engineering data and the like according to the objectives and principles of classification of gas reservoir development blocks. Basis for development block subclassification mainly includes such data as fluid properties, reservoir physical properties, and production characteristics. The method is directed to classification of development blocks on the basis in multiple aspects such as dynamic reserve evaluation, production prediction, numerical simulation study, and the like, and on the basis of the classification of development blocks, fine dynamic evaluation study on gas reservoirs is carried out, which has important directive significance for prolonging the stable production period of a gas field and enhancing the recovery.

The invention discloses a single-well multi-reservoir planar branch multi-fracture fracturing process. The process uses high-viscosity prefluid and low-viscosity prefluid to inject into the formation in two stages, and injects high-viscosity prefluid into the first half. The mixed fluid of liquid and high-efficiency fluid loss reducer is used to fracture a number of artificial fractures with a half-length greater than or equal to 300m in the formation as the main fractures, and then inject low-viscosity prefluid into the second half of the fracture, using the second half of the The frictional shear between the low-viscosity prefluid and the wall of the main fracture creates multiple branch fractures on the wall of the main fracture, thereby forming a complex artificial fracture area on the entire reservoir; realizing simultaneous compression of multiple reservoirs crack.

The invention relates to an automatic chemical feeding device and method in a foam-drainage gas recovery well. The automatic chemical feeding device mainly comprises a ground chemical storage tank, a thin pipe valve, a thin pipe, a pressure difference control valve, an oil pipe and a casing. The ground chemical storage tank, the thin pipe valve, the thin pipe and the pressure difference control valve form a chemical feeding channel, the thin pipe and the oil pipe form an annular liquid discharge channel, and the pressure difference control valve mainly comprises a chemical inlet, an upper cavity, a valve spool ball, a conical valve seat, a lower cavity, a spring and a chemical outlet. The upper end of the pressure difference control valve is stressed by chemical gravity (constant in pressure), and the lower end thereof is stressed by return pressure at bottom of the well. The more the accumulated liquid is, the higher the return pressure at the bottom of the well is and the lower the downward pressure difference stressed on the valve spool ball is, so that the spring can overcome the pressure difference to support the valve spool ball upwards and chemicals are begun to be added. After the accumulated liquid is discharged, the pressure difference is larger than elastic force of the spring and presses the valve spool ball to stop chemical feeding. The automatic chemical feeding device can automatically feed and stop feeding chemicals according to level of the accumulated liquid, and the chemicals and the accumulated liquid at the bottom can be guaranteed to be sufficiently mixed.

The invention discloses an intercommunicating unit division method and mining method for a biological reef gas reservoir. The division method comprises the steps of carrying out gas layer system division of the biological reef gas reservoir, carrying out reef intercommunication analysis of each reef unit in each gas-bearing layer system, dividing the adjacent reef units meeting a consistency result into reef intercommunicating units, performing fluid property and distribution characteristic analysis and stratum pressure system characteristic analysis on each reef unit reservoir, and dividing each reef unit reservoir meeting the consistency result into a same reservoir intercommunicating unit. According to the method for dividing the intercommunicating units of the biological reef gas reservoir, the same reservoir intercommunicating units can be divided objectively, scientifically and reasonably, a basis can be provided for scientific and reasonable balanced development technical policies of the biological reef gas reservoir, a development technical policy can be specified for each reservoir unit, and therefore, the water-free gas production period of the whole biological reef is prolonged, and the stable production period and the production degree are improved.

The present invention provides a logging interpretation method for water flooding degree of mixed reservoirs based on sedimentary microfacies and lithofacies, including: carrying out fine correlation and division of strata; conducting classification research on sedimentary microfacies-lithological facies; establishing each facies zone According to the four-property relationship chart, a log interpretation model suitable for the study area was established according to the sedimentary microfacies-lithological facies, and the actual data were processed based on the sedimentary microfacies-lithological facies discrimination model. On this basis, various types of Differences in reservoir logging interpretation; using entropy weight-based quantitative evaluation method for water-flooded layers to study water-flooded status of mixed reservoirs, establish comprehensive evaluation criteria for water-flooded layers in mixed reservoirs, and classify water-flooded oil layers , summed up the water flooding mode of the target interval. This method improves the degree of production and ultimate recovery of out-of-control reserves in mixed reservoirs, effectively reduces the decline in oilfield production, prolongs the stable production period of oilfields, significantly improves the ultimate recovery of oil reservoirs, and has achieved significant development effects and benefits.

The invention discloses a development method for realizing advanced water injection and early water injection by utilizing a horizontal well. The development method comprises the following steps: S1,selecting a region; S2, selecting the well; S3, determining an integrated injection-production scheme; S4, determining a staged fracturing scheme; S5, dredging and washing the well; S6, testing oil and seeking production; S7, perforating and fracturing a water injection section; S8, scraping and washing the well; S9, feeding an integrated injection-production tool; S10, checking and sealing the integrated injection-production tool; S11, feeding a well completion tubular column to be butted into the well; and S12, injecting water in an annulus and extracting oil by an oil pipe. The developmentmethod has the advantages that injection-production integration can be realized on one well, the water injection investment is reduced, the problems of difficulty in regional water injection and thelike are solved, the capacity can be supplemented for the stratum, the decline rate of the oil well is delayed, the stable production period of the oil well is prolonged, the oil extraction speed andthe final recovery rate of the oil well are improved, the capital recovery period is shortened, the development benefit is improved, and economic and efficient development is realized.

The invention relates to a method for tapping the remaining oil potential of high water-cut reservoirs, which includes: determining the quantitative characterization method of the reservoir flow field by analyzing the main control factors of the flow field geology of different reservoirs, and then determining the distribution law and mode of the initial flow field, and then combining the The distribution law and mode of the dominant flow field are analyzed by analyzing the post-development data of the oilfield such as the development dynamics, and finally the remaining oil is found and exploited by using the method of the difference between the dominant flow field and the initial flow field. The method for tapping the potential of remaining oil in high water-cut reservoirs provided by the present invention, on the basis of reservoir classification, deeply analyzes the influence of reservoir heterogeneity and structural characteristics on the initial flow field, and reanalyzes and compares the reservoir flow field in the later stage of development. Predominant flow field-initial flow field, forming an understanding of favorable areas for the distribution of remaining oil in the later stage of development, tapping the remaining oil in a targeted manner, improving the degree of production and ultimate recovery of out-of-control reserves in the reservoir, and effectively reducing the decline in oilfield production , significantly improving the ultimate oil recovery.

The present invention provides a method for scientifically calculating the soaking time based on the rock skeleton theory, which is to maintain the shale due to the inherent characteristics of permeability, disintegration, softening and expansion of the shale itself when the shale oil and gas are fracturing. Based on the shale skeleton structure, the hydration expansion of the complex fracture network is formed to the greatest extent. It is necessary to scientifically calculate the soaking time to achieve the optimal hydration effect of the shale. The method calculates the soaking time by introducing pressure normalized increments. Before on-site construction, it is necessary to collect cuttings (cores) at the front, middle and back ends of the well drilling process for indoor immersion experiments to obtain pressure normalized The shale soaking softening time and shale soaking disintegration time in the incremental correlation equation; and then according to the geological data, fracturing design and logging comprehensive interpretation to obtain the ion suppression coefficient and basic parameters, and determine the pressure normalization of different soaking times Increment and curve fitting to obtain the best soaking time of the well.

The invention relates to a multi-objective optimization method for reasonable well spacing of ultra-deep reef-shoal gas reservoirs, relates to the technical field of oil and gas reservoir development, and is used to solve problems in the prior art that the optimal development well pattern does not comprehensively consider the maximization of economic benefits, production Technical issues of yield maximization and multiple objectives with a certain stable production period. The method of the present invention includes the steps of establishing a multi-objective function for reasonable well spacing of reef-shoal gas reservoirs; the steps of establishing a constraint function and the step of solving the multi-objective function according to the constraint function; and solving the multi-objective function by establishing the constraint function , the value of the multi-objective function corresponding to the optimal and reasonable well spacing obtained can satisfy the maximum profit, the maximum recovery rate and the maximum stable production period at the same time, so the optimal and reasonable well spacing can provide valuable guidance for oilfield exploration , so as to obtain good social and economic benefits.

The invention relates to an underground gas production pipe string and a gas production method, comprising a velocity pipe string and a double-channel jet pump connected by a first straight joint, and a power gas inlet and an underground fluid inlet corresponding to the double-channel jet pump. The other end of the channel jet pump is connected with a suction pipe through a second straight connector, and the outer diameters of the velocity column, the double channel jet pump and the suction tube are consistent. The downhole gas production string and gas production method of the present invention can effectively perform drainage and gas recovery for gas wells with low pressure, low production and large water production, especially for multi-layer combined production, lower water flooded wells and horizontal wells. Increasing the degree of production of the production zone has significantly slowed down the rate of gas well production and pressure decline, effectively prolonging the stable production period of the gas well.

The invention discloses a water control well completion pipe string with a tripping-in variable density screen pipe and a continuous packer, and the water control well completion pipe string comprises the variable density screen pipe, a quick connector, a positioning extension cylinder, a filling sliding sleeve, a top packer, a mechanical positioner, hydrophobic gravel, a hand releasing tool and a setting tool. At present, the method is only widely applied to an oil field, water control is not achieved in a gas field, hydrophobic gravels and a variable-density screen pipe are combined and tripped into a horizontal section, and compared with the method that only a continuous packer is adopted for controlling water, the variable-density screen pipe is applied to a whole section of a shaft, and the hydrophobic gravels are filled outside the variable-density screen pipe, water control is achieved. The variable-density screen pipe has the advantages that the number of apertures of the variable-density screen pipe can be adjusted according to factors such as reservoir permeability and water conditions, water control is achieved, water breakthrough time can be greatly prolonged, formation water coning is prevented, the stable production period is prolonged, the water control and sand control effects are more obvious, and meanwhile, a referable scheme method is provided for deepwater gas reservoir well cementation and completion.