A water control process method, system and application for oil reservoir seepage field transformation

Abstract

The present invention relates to a water control process method, system and application for transformation of oil reservoir seepage field, the process method includes a two-step process method or a one-step process method; the two-step process method includes large channel plugging operation and seepage field transformation operation; large channel plugging operation includes large channel plugging section plug and large channel plugging process; seepage field transformation operation includes seepage field transformation section plug and seepage field transformation process. The oil reservoir seepage field transformation water control process method of the present invention proposes a seepage field transformation water control technology, which adopts a fracturing process, provides an effective process measure guarantee for the injection of chemical plugging agents, broadens the selection range of chemical plugging agents, exerts the synergistic effect of different chemical plugging agents, changes the seepage field of the formation near the wellbore, achieves the purpose of controlling water and increasing oil, improves the water control effect, has a large transformation range, and prolongs the effective period of water control.

Description

Technical Field

[0001] The invention belongs to the technical field of oil production engineering, and particularly relates to a water control process method, system and application of oil reservoir seepage field transformation. Background Art

[0002] As the development of medium- and high-permeability sandstone reservoirs enters the middle and late stages, the injected water or edge water advances along the high-permeability layer or high-permeability strip, causing the water content of the oil well to rise, or even violent flooding, which deteriorates the development effect of the oil field and affects the oil field recovery rate. The traditional process method is chemical water plugging. Through water-finding operations, the main water-producing layer section is found, the packer is lowered, and the chemical plugging agent is injected at a fixed point for water plugging operations. When the water-producing layer section cannot be determined or the water-producing layer section cannot be separated from other layers, the selective injection process is used to inject the plugging agent into the formation in general. Through the difference in formation permeability and the low-displacement injection process, the plugging agent is allowed to enter the dominant water flow channel first, and the large pores are blocked, thereby improving the liquid production profile and reducing the water content of the production well.

[0003] The construction process of chemical water plugging method is simple, but the success rate is low, the increase in production is low, and the effective period is short. There are two main reasons. On the one hand, it is due to the limitations of chemical plugging agents themselves: chemical plugging agents usually use resins, polymers, and inorganic chemicals (two-liquid method) to undergo cross-linking or precipitation reactions underground to form high-viscosity or solid-phase materials to block water channeling channels. However, chemical plugging agents will undergo shear damage, dilution, temperature changes, and poor effective mixing of two liquids during stratum migration, resulting in insufficient underground chemical reactions, low strength of the formed plugging products, and poor plugging effects. On the other hand, it is due to the limitations of the injection process: the low-displacement injection process allows chemical plugging agents to enter the main water flow dominant channel, while the secondary water flow dominant channel is not blocked. Therefore, when the main water flow dominant channel is blocked, the secondary water flow dominant channel quickly develops into the main water flow dominant channel, resulting in failure of the water plugging operation.

[0004] Therefore, in order to improve the water control and oil increase effect and extend the effective period of water control, it is urgent to provide a water control process method and system for oil reservoir seepage field transformation to solve the technical problems existing in the above-mentioned prior art. Summary of the invention

[0005] In view of the above problems, the present invention provides a method, system and application of water control in seepage field transformation of oil reservoirs, which is mainly suitable for water control in seepage field transformation of medium and high permeability sandstone oil reservoirs and is an offensive water plugging operation method.

[0006] A water control process for oil reservoir seepage field transformation, the process comprising a two-step process or a one-step process;

[0007] The two-step process includes large pore plugging and seepage field transformation.

[0008] The large pore plugging operation includes large pore plugging slugs and large pore plugging processes;

[0009] The seepage field transformation operation includes a seepage field transformation segment plug and a seepage field transformation process.

[0010] Further,

[0011] The one-step process method includes: slug design and fracturing process;

[0012] The slug design includes protection slug, large pore blocking slug and seepage field transformation slug;

[0013] The fracturing process specifically adopts the fracturing process to complete the injection of the protection segment plug, the large pore blocking segment plug and the seepage field transformation segment plug.

[0014] Further,

[0015] The large pore plugging section in the large pore plugging operation of the two-step process method is specifically as follows: according to the reservoir physical properties and pore throat distribution characteristics, a plugging agent is used to prepare an aqueous solution of a certain concentration, that is, a large pore plugging section is prepared;

[0016] The plugging agent includes inorganic mineral polymers, high-strength gel or jelly.

[0017] Further,

[0018] In the seepage field transformation operation of the two-step process method, the seepage field transformation slug specifically includes a main slug and a tailing slug;

[0019] The main slug is formed by selecting quartz sand, ceramsite or water-controlling filler of a certain particle size according to the pore throat distribution characteristics of the formation and the "non-steady-state" ideal filling theory, and mixing it with the sand-carrying fluid. The permeability of the slug formed after accumulation is lower than the original formation permeability;

[0020] The tail-chasing slug is made of sand or coated sand with a mesh size of 30-50 or 40-60 according to the formation permeability characteristics, and is mixed with a sand-carrying fluid. The permeability of the slug formed after accumulation is higher than the original formation permeability.

[0021] The particle size of the water-controlling filler matches the particle size of the quartz sand or ceramsite.

[0022] Further,

[0023] The slug permeability formed after the main slug is accumulated is 40%-80% of the original formation permeability;

[0024] The permeability of the slug formed after the tail-chasing slug is accumulated is 3 to 5 times the permeability of the original formation;

[0025] The water control filler is a selective chemical plugging agent with dual control of "temperature-crude oil", including oil-soluble resin, paraffin, polyethylene wax or modified slow-swelling particles.

[0026] Furthermore, the sand-carrying fluid is a high-viscosity fluid with sand-carrying capacity prepared by dissolving hydroxypropyl guar gum in water.

[0027] Furthermore, the large-pore plugging process of the two-step process method is specifically as follows: a large-pore plugging segment plug is injected into the formation using a pump truck.

[0028] Furthermore, the seepage field transformation process of the two-step process method is specifically as follows: a fracturing vehicle group is used to inject a seepage field transformation segment plug into the artificial fractures formed by fracturing and the near-wellbore area to form a filling area with differentiated oil-water permeability.

[0029] Further,

[0030] The protective segment plug in the one-step process is specifically prepared by selecting a water-controlling filler according to the pore throat diameter and the large pore diameter of the formation matrix and mixing it with a sand-carrying fluid.

[0031] Further,

[0032] The large pore plugging section in the one-step process method is specifically to select a granular plugging agent or an underground cross-linked chemical plugging agent with a particle size larger than the matrix pore throat and smaller than the large pore diameter, add it to the sand-carrying liquid or water and stir evenly to form a large pore plugging section;

[0033] The chemical plugging agents include slow-swelling particles, inorganic mineral aggregates, high-strength gel or jelly or resin plugging agents.

[0034] Further,

[0035] The method of transforming the seepage field slug in the one-step process is the same as the method of transforming the seepage field slug in the two-step process.

[0036] The present invention also provides a water control process system for oil reservoir seepage field transformation, wherein the process system comprises a two-step process system or a one-step process system;

[0037] The two-step process system includes a large pore plugging operation unit and a seepage field transformation operation unit;

[0038] The large pore plugging operation unit includes a large pore plugging section plug and a large pore plugging process;

[0039] The seepage field transformation operation unit includes a seepage field transformation segment plug and a seepage field transformation process.

[0040] Further, the one-step system method includes: a slug design unit and a fracturing process unit;

[0041] The slug design unit is used to generate protection slugs, large pore blocking slugs and seepage field transformation slugs;

[0042] The fracturing process unit is used to complete the injection of the protection segment plug, the large pore blocking segment plug and the seepage field transformation segment plug by adopting the fracturing process.

[0043] Furthermore, the process method is applied to water control in seepage field transformation of medium and high permeability sandstone reservoirs.

[0044] Furthermore, the process system is applied to water control in seepage field transformation of medium and high permeability sandstone reservoirs.

[0045] The oil reservoir seepage field transformation water control process method of the present invention organically combines conventional chemical water plugging with fracturing technology, and proposes a seepage field transformation water control technology. The technology adopts the fracturing technology, provides effective process measures to ensure the injection of chemical plugging agents, broadens the selection range of chemical plugging agents, and exerts the synergistic effect of different chemical plugging agents, changes the seepage field of the formation near the wellbore, achieves the purpose of water control and oil increase, improves the water control effect, has a large transformation range, and extends the effective period of water control.

[0046] Other features and advantages of the present invention will be described in the following description, and part of them will become obvious from the description, or be understood by practicing the present invention. The purpose and other advantages of the present invention can be obtained from the description and claims. DETAILED DESCRIPTION

[0047] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0048] The present invention provides a water control process for oil reservoir seepage field transformation. The technical principle of the method is to reconstruct the seepage field in different flooded areas in medium-high permeability sandstone reservoirs with obvious intra-layer permeability differences, change the water drive flow channel, increase the water drive sweep volume, and achieve the purpose of water control and oil increase. The process method includes a two-step process method or a one-step process method;

[0049] The two-step process includes large pore plugging and seepage field transformation.

[0050] The large pore plugging operation includes large pore plugging slugs and large pore plugging processes;

[0051] The seepage field transformation operation includes a seepage field transformation segment plug and a seepage field transformation process.

[0052] The one-step process method includes: slug design and fracturing process;

[0053] The slug design includes protection slug, large pore blocking slug and seepage field transformation slug;

[0054] The fracturing process specifically adopts the fracturing process to complete the injection of the protection segment plug, the large pore blocking segment plug and the seepage field transformation segment plug.

[0055] The large pore plugging section in the large pore plugging operation of the two-step process method is specifically as follows: according to the reservoir physical properties and pore throat distribution characteristics, inorganic mineral polymers, high-strength gel or jelly are used as plugging agents to prepare a certain concentration of aqueous solution, that is, the large pore plugging section is prepared;

[0056] Inorganic mineral polymers, high-strength gels or jelly plugging agents are injected into the formation, and low-volume injection is used to selectively inject them into large pores or dominant water flow channels (when using low-volume injection technology, the plugging fluid will naturally choose to plug those large channels or water flow dominant channels with the smallest flow resistance) to plug the heavily flooded areas, completely block the water flow dominant channels, and force the water to completely change its flow trajectory.

[0057] Chemical plugging materials such as inorganic mineral polymers, high-strength gels or jelly have high viscosity, poor fluidity, and high permeability, and thus have a large plugging rate. The residual resistance coefficient after plugging increases with the increase of water injection rate and has a good double logarithmic relationship. In addition, experiments have shown that combining the inorganic mineral polymer, gel or jelly advantageous channel plugging technology with chemical adjustment and displacement technology can achieve the dual effect of "plugging + oil displacement", and the effect of increasing oil and reducing water is more obvious; as the plugging distance increases, the time for the oil displacement agent and water to return to the large pores in the matrix of the low permeability layer and the high permeability layer is delayed, the affected area increases, and the recovery rate increases. Therefore, the above chemical materials are injected into the formation to plug the large pores or advantageous water flow channels and prepare for the subsequent seepage field transformation.

[0058] The seepage field transformation slug specifically includes a main slug and a tailing slug: the main slug is selected according to the distribution characteristics of pore throats in the formation and in accordance with the "non-steady-state" ideal filling theory, and quartz sand or ceramsite and water-controlling filler of a certain particle size are selected (the particle size of the water-controlling filler matches the particle size of the quartz sand or ceramsite), so that the permeability of the slug formed after accumulation is 40%-80% of the original formation permeability. The particle size selection and the design of the water-controlling filler addition ratio are determined according to the permeability value of the indoor sand filling pipe. The water-controlling filler includes oil-soluble resin, paraffin, polyethylene wax or modified slow-swelling particles.

[0059] The tail-chasing segment plug is formed by mixing the sand-carrying fluid with 30-50 or 40-60 mesh sand or coated sand. After the segment plug is filled in the area near the wellbore, a filling zone with a permeability higher than the formation permeability is formed, thereby improving the oil drainage capacity.

[0060] The sand-carrying fluid is a high-viscosity fluid with sand-carrying capacity, prepared by dissolving hydroxypropyl guar gum in water.

[0061] The large-channel plugging process of the two-step process method is specifically as follows: a pump truck is used to inject the large-channel plugging segment into the formation. Construction displacement 0.2-1.0m 3 / min, wellhead pressure 2-15MPa, plugging radius 50-80m. The purpose is to strongly plug large pores or water flow dominant channels, forcing water to change its flow direction, thereby increasing the water swept volume and improving water flooding efficiency.

[0062] The seepage field transformation process of the two-step process method is specifically as follows: a fracturing vehicle group is used to inject the seepage field transformation segment plug into the artificial fractures formed by fracturing and the area near the wellbore to form a filling area with differentiated oil and water permeability. Construction displacement 2.5-4m 3 / min, construction pressure 15-36MPa, average sand ratio 20%-40%. The construction purpose is to use the fracturing process to open an artificial fracture in the weakly flooded and non-flooded areas, and fill the seepage field transformation section plug into the artificial fracture and the near-wellbore area under the carrier of the sand-carrying fluid, forming a transformation area with differentiated oil-water permeability, and achieving the purpose of controlling water and increasing oil.

[0063] Among them, the protective segment plug in the one-step process method is specifically a selective plugging material (i.e., water-controlling filler) with a suitable particle size distribution selected according to the pore throat diameter and large pore diameter of the formation matrix, which can plug water but not oil, including oil-soluble resin, asphalt, paraffin, polyethylene wax, etc., to form a protective layer similar to "mud cake" in the residual oil-rich zone to prevent subsequent chemical plugging agents from invading the matrix pores and causing pollution, which is not conducive to the potential of residual oil. At the same time, these plugging agents also play a role in reducing liquid filtration loss, improving liquid seam-making efficiency, and expanding the scope of transformation. The above-selected selective plugging materials are added to the sand-carrying fluid and mixed evenly to form a protective segment plug.

[0064] The specific method of large-pore plugging segment plug is: select granular plugging agents or underground cross-linked chemical plugging agents with a particle size larger than the matrix pore throat diameter and smaller than the large-pore diameter to strongly plug the large-pore, and use the over-displacement method to prevent the chemical plugging agents from polluting the residual oil-rich zone. Applicable chemical plugging agents include but are not limited to slow-swelling particles, inorganic mineral polymers, high-strength gels, gels, phenolic resins, urea-formaldehyde resins and other strong plugging chemical plugging agents. Segment plug formula: Add the above preferred plugging agents to the sand-carrying fluid or water and stir evenly to form a large-pore plugging segment plug.

[0065] The seepage field transformation slug designed in the one-step process is the same as the method of the seepage field transformation slug in the two-step process.

[0066] Then, the fracturing technology is used to complete the injection of three plugs: protection plug, large pore plugging plug and seepage field transformation plug, to protect the remaining oil-enriched area, plug the large pores or water flow dominant channels at the front edge of the artificial fractures, reduce the filtration loss, increase the fracture width as much as possible, and expand the scope of seepage field transformation; fill the artificial fractures formed in the secondary water flow dominant channels and the remaining oil-enriched area to form a seepage field with oil-water differences, and achieve the goal of controlling water and increasing oil; and selectively carry out sand prevention operations depending on the sand production of the formation.

[0067] Compared with traditional chemical water plugging, the present invention has a large transformation range, a long effective period, and a significant oil-increasing effect. The innovation of this invention is reflected in three aspects: First, process innovation, abandoning the low-displacement injection process of traditional chemical water plugging, and adopting a fracturing process, which can not only achieve water control, but also has an oil-increasing effect, and improves the aggressiveness of water control measures. Second, the transformation of underground crude oil flow state. Fracturing of medium and high permeability sandstone reservoirs forms short and wide vertical cracks, establishes a crack in the residual oil enrichment zone, and transforms the seepage of crude oil into a double-wing linear flow, which greatly reduces the oil flow resistance, helps to tap the potential of the remaining oil, and improves the ultimate recovery rate. The third is the construction of a differentiated permeability field. Applying the "non-steady-state" ideal filling theory, quartz sand or ceramsite with a specific particle size distribution and water-controlling particle fillers are selected and mixed in a certain proportion and then filled into the fractures, so that the water phase permeability of the fracture filling body is 40%-80% of the original formation water phase permeability, while the oil phase permeability is increased to more than 3 times the original oil phase permeability of the residual oil-enriched zone by utilizing the "water blocking and oil-repelling" characteristics of the water-controlling filler, thereby realizing the construction of the oil-water differentiated seepage field in the fracture filling body, forcing water to enter the matrix for oil displacement, while crude oil quickly enters the oil well along the fractures, thereby achieving the purpose of water control and oil increase. Among them, the water-controlling filler is a selective chemical plugging agent with dual control of "temperature-crude oil", including but not limited to oil-soluble resins, paraffin wax, polyethylene wax, modified slow-swelling particles and other types of materials, which can be freely selected according to the formation temperature to achieve accurate control of the differentiation of oil-water permeability, which is an important guarantee for achieving the construction of differentiated permeability.

[0068] The present invention also provides a water control process system for oil reservoir seepage field transformation, the process system comprising:

[0069] The process system includes a two-step process system or a one-step process system;

[0070] The two-step process system includes a large pore plugging operation unit and a seepage field transformation operation unit; the large pore plugging operation unit includes a large pore plugging section plug and a large pore plugging process; the seepage field transformation operation unit includes a seepage field transformation section plug and a seepage field transformation process.

[0071] The one-step system method comprises: a slug design unit and a fracturing process unit;

[0072] The slug design unit includes a protective slug, a large pore channel plugging slug and a seepage field transformation slug; the fracturing process unit specifically uses a fracturing process to complete the injection of the protective slug, the large pore channel plugging slug and the seepage field transformation slug.

[0073] The present invention provides a method and system for water control in seepage field transformation of oil reservoirs, which is mainly applicable to water control in seepage field transformation of medium and high permeability sandstone oil reservoirs, and can reduce water and increase oil production in oil wells in the medium and high water content period, thereby improving the recovery rate.

[0074] Example 1: Two-step process

[0075] In a medium-high permeability and strong edge water sandstone reservoir, the oil layer thickness is 5m. Natural energy development, water injection development, and CO2 huff and puff have been developed for a total of 27 years. The long-term scouring of injected water and edge water has formed water flow advantage channels and large pores. Water or gas directly rushes into the oil well along the large pores, resulting in ineffective water injection or gas injection development. For this oil reservoir, the seepage field transformation water control process method mentioned in the embodiment of the present invention is used for operation.

[0076] Large channel plugging operation. Use ordinary pump truck to squeeze in 170m 3 The inorganic mineral polymer plugging agent system blocks the dominant water flow channels and large pores. The plugging agent system formula: 80% water + 20% inorganic mineral polymer + 3% catalyst, displacement 0.6m 3 / min, injection pressure 10-14.8MPa, wait for 15h before proceeding to the next step.

[0077] Seepage field reconstruction operation. Prepare 175m according to the formula of 0.3% guar gum + 40% 40-70 mesh silt sand + 10% oil-soluble plugging agent. 3 Main segment plug: 10m3 water + 0.3% guar gum + 20%-30% 20-40 mesh coated sand 3 Tail-chasing plug: The main plug and tail-chasing plug are injected into the formation in sequence by a fracturing vehicle group, with a construction displacement of 2.7-4.0m 3 / min, construction pressure 21-35.6MPa.

[0078] After the construction was completed, the well was shut down for one day and then put into production.

[0079] The screw pump was used to complete the well on December 15, 2019. The initial daily liquid production was 37 cubic meters, the daily oil production was 5.1 tons, the maximum daily oil production was 11.2 tons, the current daily liquid production is 32.9 cubic meters, the daily oil production is 8.04 tons, and the water content is 78%. As of May 10, 2021, the cumulative oil production has increased by 3,232 tons, with a cumulative validity period of 492 days.

[0080] Example 2: One-step process

[0081] A medium-high permeability sandstone reservoir with a burial depth of 2700-3200m, an average porosity of 19.5%, and an average permeability of 265*10 - 3 um 2 The main oil layer is 35.6m thick. After 13 years of water injection development, the injected water rushes into the oil well along the bottom of the reservoir, causing the oil well to be shut down due to high water content. For this oil reservoir, the one-step construction process of the seepage field transformation water control process method proposed in the present invention is used for construction work.

[0082] Construction displacement 2.2-5.5m 3 / min, construction pressure 30-65.0MPa, reservoir protection plug 120m 3 (water + 0.3% guar gum + 15% 5-10um water control granular material), large channel plugging section 200m 3 (water + 20% high strength gel), seepage field transformation plug 80m 3 (0.3% guar gum + 20-40% 40-70 mesh silt sand + 10% oil-soluble plugging agent), add 35m3 of 40-70 mesh / 30-50 mesh quartz sand 3 , high strength gel 40m 3 , water control material 18m 3 , oil-soluble plugging agent 8m 3 .

[0083] After the construction is completed, the well will be shut down for 1 day, the fluid will be drained, and production will begin.

[0084] The present invention proposes a water control process method for transforming the seepage field of medium-high permeability sandstone reservoirs in the high water content period. The method is to apply the innovative fracturing process to medium-high permeability sandstone reservoirs. Due to the loose formation, fracturing is easy to form short and wide vertical seams, which is conducive to communicating vertical residual oil, changing the oil flow channel from seepage to linear flow, and greatly reducing the oil flow resistance. At the same time, due to the application of the fracturing process, the selection of chemical plugging agents is wider, avoiding the restriction of the conventional low-displacement injection method on the selection of chemical plugging agents. For example, granular chemical plugging agents are difficult to migrate deeply in the formation under low-displacement injection, so they cannot be used in conventional chemical water plugging operations, or have relatively high requirements for particle size and particle deformability. However, the method of injecting plugging agents in the fracturing process makes the injection of chemical plugging agents relatively easy, and any type of chemical plugging agents can be selected according to the needs of water control, which is more conducive to the success of chemical water plugging. Moreover, by designing the fracture filling material, a seepage field with differentiated permeability of oil and water is formed in the fracture, the water phase permeability is reduced, and the oil phase permeability is increased, thereby achieving the purpose of controlling water and increasing oil. The present invention is suitable for the treatment of water-injected single-layer (water-flooded) layers, and is also suitable for the treatment of high-water-content oil wells where strong bottom edge water advances along local high-permeability strips. By reconstructing the seepage field of different flooded areas in medium- and high-permeability sandstone reservoirs with large inter-layer or intra-layer permeability differences, changing the water drive flow channel, and increasing the water drive swept volume, the purpose of controlling water and increasing oil production is achieved.

[0085] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A water control process for oil reservoir seepage field transformation, It is characterized in that The process includes a two-step process or a one-step process; The one-step process method includes: slug design and fracturing process; the slug design includes protection slug, large pore plugging slug and seepage field transformation slug; The two-step process includes large pore plugging and seepage field transformation. The large pore plugging operation includes large pore plugging slugs and large pore plugging processes; The seepage field transformation operation includes seepage field transformation slugs and seepage field transformation processes; The seepage field transformation slug in the one-step process is the same as the seepage field transformation slug in the two-step process; the seepage field transformation slug specifically includes a main slug and a tailing slug; The main slug is formed by selecting quartz sand or ceramsite and water-controlling filler of a certain particle size according to the distribution characteristics of pore throats in the formation and in accordance with the "non-steady-state" ideal filling theory, and mixing them with sand-carrying fluid. The permeability of the slug formed after accumulation is lower than the permeability of the original formation. The tail-chasing slug is formed by selecting sand of 30-50 mesh or 40-60 mesh according to the formation permeability characteristics and mixing it with the sand-carrying fluid. The permeability of the slug formed after accumulation is higher than the original formation permeability. The particle size of the water-controlling filler matches the particle size of the quartz sand or ceramsite.

2. The water control process for oil reservoir seepage field transformation according to claim 1, It is characterized in that The fracturing process specifically adopts the fracturing process to complete the injection of the protection segment plug, the large pore blocking segment plug and the seepage field transformation segment plug.

3. The water control process for oil reservoir seepage field transformation according to claim 1, It is characterized in that The large pore plugging section in the large pore plugging operation of the two-step process method is specifically as follows: according to the reservoir physical properties and pore throat distribution characteristics, a plugging agent is used to prepare an aqueous solution of a certain concentration, that is, a large pore plugging section is prepared; The plugging agent includes inorganic mineral polymers, high-strength gel or jelly.

4. The water control process for oil reservoir seepage field transformation according to claim 1, It is characterized in that The permeability of the slug formed after the main slug is accumulated is 40%-80% of the original formation permeability; The permeability of the slug formed after the tail-chasing slug is accumulated is 3 to 5 times the permeability of the original formation; The water control filler is a selective chemical plugging agent with dual control of "temperature-crude oil", including oil-soluble resin, paraffin, polyethylene wax or modified slow-swelling particles.

5. The water control process for oil reservoir seepage field transformation according to claim 1, It is characterized in that The sand-carrying fluid is a high-viscosity fluid with sand-carrying capacity, prepared by dissolving hydroxypropyl guar gum in water.

6. The water control process for oil reservoir seepage field transformation according to claim 3, It is characterized in that The large-pore plugging process of the two-step process method is specifically as follows: a large-pore plugging segment plug is injected into the formation by a pump truck.

7. The water control process for oil reservoir seepage field transformation according to claim 1, It is characterized in that The seepage field transformation process of the two-step process method is specifically as follows: a fracturing vehicle group is used to inject a seepage field transformation segment plug into the artificial fractures formed by fracturing and the area near the wellbore, so as to form a filling area with differentiated oil-water permeability.

8. The water control process for oil reservoir seepage field transformation according to claim 2, It is characterized in that The protective segment plug in the one-step process is specifically prepared by selecting a water-controlling filler according to the pore throat diameter and the large pore diameter of the formation matrix and mixing it with a sand-carrying fluid.

9. The water control process for oil reservoir seepage field transformation according to claim 2, It is characterized in that The large pore plugging section in the one-step process method is specifically to select an underground cross-linked chemical plugging agent with a particle size larger than the matrix pore throat and smaller than the large pore diameter, add it to the sand-carrying liquid or water, and stir evenly to form a large pore plugging section; The underground cross-linked chemical plugging agents include slow-swelling particles, inorganic mineral polymers, high-strength gel or jelly or resin plugging agents.

10. The water control process for oil reservoir seepage field transformation according to claim 2, It is characterized in that The large pore plugging section in the one-step process method is specifically to select a granular plugging agent with a particle size larger than the matrix pore throat and smaller than the large pore diameter, add it to the sand-carrying liquid or water, and stir it evenly to form the large pore plugging section.

11. An application of the water control process for oil reservoir seepage field transformation as claimed in any one of claims 1 to 10, It is characterized in that The process method is applied to water control in seepage field transformation of medium and high permeability sandstone reservoirs.