Horizontal well immovable string profile control plugging and displacement method

Abstract

The invention discloses a horizontal well immovable string profile control plugging and displacement method, and relates to the technical field of oil development. According to the horizontal well immovable string profile control plugging and displacement method, water absorption indexes are graded, a water-soluble temporary plugging agent is selected to be added into an oil pipe or an oil-soluble temporary plugging agent and an imbibition agent are selected to be added into a sleeve under different water absorption indexes, the water absorption indexes are gradually reduced, and the effects of profile control plugging and displacement are achieved. The method does not need to move a tubular column, is simple to operate and is suitable for industrial application.

Description

Technical Field

[0001] The invention belongs to the field of petroleum development, and in particular relates to a method for adjusting plugging and driving of a horizontal well fixed pipe string. Background Art

[0002] At present, horizontal well development has gradually become one of the development methods of ultra-low permeability oilfields. In order to improve the effect of horizontal wells, some oilfields have begun to explore the development model of same-well injection and production. However, field tests have found that there are problems such as rapid production decline, rapid water breakthrough, and easy water breakthrough, which seriously restrict the production of horizontal wells.

[0003] In order to restore the production capacity of high-water-content horizontal wells, two methods are generally used: temporary plugging and fracturing or water plugging. The construction process of temporary plugging and fracturing of horizontal wells requires the use of construction pipe strings, which has high transformation intensity and long construction period. Horizontal well water plugging is currently mainly used in high-water-content wells. It is necessary to treat the wellbore, lift the pipe string, inject the plugging agent and then seal it. Chinese patent CN111577196A discloses a method for plugging water in high-water-content horizontal wells in oil fields. It mainly inserts a cannula into the oil reservoir, sets a solvent release device on the cannula near the plug head, and then injects a solvent from the cannula. The solvent and the fluid in the high-water-content section of the formation scale to form a plug, thereby achieving water plugging and achieving the purpose of restoring production. This method realizes the operation of the pipe string without moving, but can only seal the production end, and cannot adjust the injection end. Summary of the invention

[0004] The main purpose of the present invention is to provide a horizontal well fixed pipe plugging and driving method to solve the problems in the prior art that the pipe needs to be moved during injection and production in the same well, the engineering workload is large, or the plugging effect is poor.

[0005] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, a method for adjusting plugging and driving of a horizontal well without moving the tubing string is provided, which can simultaneously plug the production end and adjust the injection end without moving the tubing string, thereby reducing the water content of the horizontal well and increasing the crude oil production. The horizontal well includes a casing and an oil pipe, and the oil pipe is located inside the casing;

[0006] The plugging and driving method of the horizontal well fixed pipe string includes:

[0007] Calculate the pseudo water absorption index. Under the first condition, inject water into the casing, and then inject the oil-soluble temporary plugging agent. After the reaction is completed, calculate the squeeze liquid water absorption index. When the squeeze liquid water absorption index still meets the first condition, repeat the above steps.

[0008] Under the second condition, inject a water-soluble temporary plugging agent into the oil pipe, control the squeezing pressure to 15MPa-23MPa, and then inject an imbibition agent into the casing; repeat the above steps when the squeezing liquid water absorption index still meets the second condition;

[0009] Under the third condition, a clay stabilizer solution is injected into the casing to react and complete plugging and flooding.

[0010] The pseudo-water absorption index is the average value of the ratio of the difference between the daily water injection volume and the daily liquid production volume of the horizontal well in the first three months to the daily oil-water well pressure difference;

[0011] The squeeze water absorption index is the ratio of the instantaneous liquid volume of squeezed water to the squeeze pressure during horizontal well construction;

[0012] The first condition is that the pseudo water absorption index is greater than 3m 3 / (d·MPa);

[0013] The second condition is that the squeeze water absorption index is less than or equal to 3m 3 / (d·MPa), greater than 2m 3 / (d·MPa);

[0014] The third condition is that the squeeze water absorption index is less than or equal to 2m 3 / (d·MPa).

[0015] Furthermore, the water-soluble temporary plugging agent is a water-soluble microemulsion type temporary plugging agent;

[0016] According to the mass fraction, the water-soluble temporary plugging agent includes: 10%-20% of the first surfactant, 10%-15% of the first oil-soluble plugging material, and 5%-8% of the first corrosion inhibitor; and / or

[0017] According to the mass fraction, the oil-soluble temporary plugging agent includes: 4%-7% of the second oil-soluble plugging material, 15%-20% of the nanofiber, 3%-5% of the first pH regulator, and 15%-20% of the second corrosion inhibitor; and / or

[0018] Calculated by mass fraction, the imbibing agent includes: 23%-28% of the second surfactant, 3%-5% of the second pH regulator, and 8%-10% of the polymer.

[0019] Further, the first surfactant includes at least one of alkylphenol polyoxyethylene ether, C12-18 fatty alcohol polyoxyethylene ether, and sorbitan ester; and / or

[0020] The first oil-soluble plugging material includes at least one of bone glue, peach gum, and natural rubber; and / or

[0021] The first corrosion inhibitor includes at least one of benzoic acid and sorbic acid; and / or

[0022] The second oil-soluble plugging material includes at least one of asphaltene and resin; and / or

[0023] The first pH adjusting agent includes at least one of sodium hydroxide, potassium carbonate, and sodium carbonate; and / or

[0024] The second corrosion inhibitor comprises at least one of hexadecylpyridinium bromide, tallow amine, and octadecylamine; and / or

[0025] The second surfactant includes sodium dodecylbenzene sulfonate, nano-iron tetroxide (Fe 3 O 4 ), at least one of nano silicon dioxide; and / or

[0026] The second pH adjuster is at least one of sodium hydroxide, sodium carbonate, and potassium carbonate; and / or

[0027] The polymer includes at least one of polyacrylamide and polyethylene glycol; and / or

[0028] The clay stabilizer solution is an aqueous solution with a clay stabilizer mass fraction of 5%-8%, and the clay stabilizer contains at least one of potassium chloride and ammonium chloride.

[0029] Furthermore, the first surfactant is alkylphenol polyoxyethylene ether, the first oil-soluble plugging material is bone glue, and the first corrosion inhibitor is benzoic acid; and / or

[0030] The second oil-soluble plugging material is asphaltene, the asphaltene is rock asphalt, and the second corrosion inhibitor is hexadecylpyridinium bromide; and / or

[0031] The second surfactant is a compound of sodium dodecylbenzene sulfonate and nano-ferroferric oxide; and / or

[0032] The polymer is polyacrylamide.

[0033] Furthermore, in the second surfactant, the mass ratio of sodium dodecylbenzene sulfonate to nano-ferroferric oxide is (8-10):(15-18).

[0034] Furthermore, the preparation method of the water-soluble temporary plugging agent is: melt the first oil-soluble plugging material, then add the first surfactant and the first corrosion inhibitor thereto, and then add water or a mixture of water and measure flowback liquid to obtain the water-soluble temporary plugging agent.

[0035] Furthermore, the preparation method of the oil-soluble temporary plugging agent is: melting the second oil-soluble plugging material, then adding nanofibers, the second corrosion inhibitor and the first pH adjuster thereto, stirring, then cooling to obtain solid particles, and finally mixing with a solvent to obtain the oil-soluble temporary plugging agent.

[0036] Furthermore, the stirring condition is 3000r / min-4000r / min; and the solvent includes at least one of white oil and kerosene.

[0037] Furthermore, for an oil layer with a porosity of 5%-8% and a reservoir thickness of 4m-12m, under the first condition, the mass of water injected into the casing each time is 15m 3 -20m 3 Under the first condition, the mass of the oil-soluble temporary plugging agent injected into the casing each time is 1t-2t, and the reaction time is 12h-24h; under the second condition, the mass of the water-soluble temporary plugging agent injected into the oil pipe each time is 1t-2t, and the mass of the imbibition agent injected into the casing each time is 2t-3t; under the third condition, the reaction time is 12h-24h.

[0038] Furthermore, the initial water content of the horizontal well is above 60%; the initial water content is the average water content of the produced product one month before.

[0039] By applying the technical solution of the present invention, water-soluble temporary plugging agents, oil-soluble temporary plugging agents or imbibing agents are injected into the casing or oil pipe in stages according to the water absorption index, so that plugging and driving of the horizontal well can be achieved simultaneously, which is helpful to improve the output and quality of crude oil, and the required amount of temporary plugging agents and imbibing agents is relatively small, the cost is low, and the operation is simple. DETAILED DESCRIPTION

[0040] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below in conjunction with the embodiments.

[0041] Injection and production in the same well refers to an oilfield development method that performs water injection and oil production operations in one well at the same time. This method is mainly used in oilfields where the production capacity of oil wells is declining rapidly or has entered the late development stage. By injecting water into the oil layer, the pressure inside the oil layer can be increased, the flow of oil can be promoted, and the oil production efficiency can be improved. At the same time, through oil production operations, the oil in the oil well can be pumped out, so that the reserves of the oil field can be effectively utilized. However, in actual operations, it is found that the use of the injection and production mode in the same well has problems such as rapid production decline, rapid water breakthrough, and easy water channeling. The existing solutions often fail to achieve the purpose of simultaneous water plugging and drive adjustment, and it is difficult to give full play to the original advantages of injection and production in the same well.

[0042] In order to solve the above technical problems, the present application provides a method for adjusting plugging and driving of a horizontal well fixed pipe string, wherein the horizontal well contains casing and oil pipe, and the oil pipe is located inside the casing;

[0043] The plugging and driving method of the horizontal well fixed pipe string includes:

[0044] Calculate the pseudo water absorption index. Under the first condition, inject water into the casing, and then inject the oil-soluble temporary plugging agent. After the reaction is completed, calculate the squeeze liquid water absorption index. When the squeeze liquid water absorption index still meets the first condition, repeat the above steps.

[0045] Under the second condition, inject a water-soluble temporary plugging agent into the oil pipe, control the squeezing pressure to 15MPa-23MPa, and then inject an imbibition agent into the casing; repeat the above steps when the squeezing liquid water absorption index still meets the second condition;

[0046] Under the third condition, a clay stabilizer solution is injected into the casing to react and complete plugging and flooding. The reaction is faster and more complete after the well is shut in.

[0047] The pseudo-water absorption index is the average value of the ratio of the difference between the daily water injection volume and the daily liquid production volume of the horizontal well in the first three months to the daily oil-water well pressure difference;

[0048] The squeeze water absorption index is the ratio of the instantaneous liquid volume of squeezed water to the squeeze pressure during horizontal well construction;

[0049] The pseudo-water absorption index and the squeeze water absorption index both characterize the performance characteristics of the formation; among them, the instantaneous liquid volume and squeeze pressure can be directly read on the monitoring instrument on the squeeze injection vehicle through squeezing water.

[0050] The first condition is that the pseudo water absorption index is greater than 3m 3 / (d·MPa);

[0051] The second condition is that the squeeze water absorption index is less than or equal to 3m 3 / (d·MPa), greater than 2m 3 / (d·MPa);

[0052] The third condition is that the squeeze water absorption index is less than or equal to 2m 3 / (d·MPa).

[0053] The plugging effect of the horizontal well can be judged according to the water absorption index. When the water absorption index is high, directly adding an oil-soluble temporary plugging agent into the casing can quickly plug water and reduce the water content of the horizontal well. However, increasing the dosage of the oil-soluble temporary plugging agent to reduce the water content to the target value is likely to cause plugging. The present application can control the water absorption capacity of the formation in both directions at the injection end and the production end by adding oil-soluble temporary plugging agents, water-soluble temporary plugging agents and imbibition agents in a graded manner, thereby improving the fluidity of the formation oil while adjusting the plugging and reducing the water content, thereby increasing the production and improving the quality of the oil.

[0054] As a preferred embodiment of the present invention, the water-soluble temporary plugging agent is a water-soluble microemulsion temporary plugging agent;

[0055] According to the mass fraction, the water-soluble temporary plugging agent includes: 10%-20% of the first surfactant, 10%-15% of the first oil-soluble plugging material, and 5%-8% of the first corrosion inhibitor; and / or

[0056] According to the mass fraction, the oil-soluble temporary plugging agent includes: 4%-7% of the second oil-soluble plugging material, 15%-20% of the nanofiber, 3%-5% of the first pH regulator, and 15%-20% of the second corrosion inhibitor; and / or

[0057] Calculated by mass fraction, the imbibing agent includes: 23%-28% of the second surfactant, 3%-5% of the second pH regulator, and 8%-10% of the polymer.

[0058] By grafting surfactants on the surface of oil-soluble plugging materials, a water-soluble microemulsion temporary plugging agent can be obtained, which will not dissolve in the oil. When added to the oil pipe, it can bridge and block the flow channel of water at the production end.

[0059] Adding corrosion inhibitors to water-soluble temporary plugging agents and oil-soluble temporary plugging agents can slow down the corrosion process of oil pipes and casings and increase the service life of equipment. The oil-soluble temporary plugging agent material can improve its plugging effect by compounding oil-soluble plugging materials and nanofibers. Adding pH regulators to adjust the reaction environment can help enhance the plugging effect of oil-soluble temporary plugging materials and nanofibers.

[0060] Controlling the amount of surfactant, second pH adjuster and polymer in the imbibition agent to meet the above conditions can improve the wettability of water to the pipe in the horizontal well, and increase the pressure in the well after being easily introduced into the formation, thereby improving the fluidity of the oil and increasing the production. By limiting the timing of adding the oil-soluble temporary plugging agent, the water-soluble temporary plugging agent and the imbibition agent and their components as described above, the oil production and oil quality of the horizontal well are improved.

[0061] As a preferred embodiment of the present invention, the first surfactant includes at least one of alkylphenol polyoxyethylene ether, C12-18 fatty alcohol polyoxyethylene ether, and sorbitan ester; and / or

[0062] The first oil-soluble plugging material includes at least one of bone glue, peach gum, and natural rubber; and / or

[0063] The first corrosion inhibitor includes at least one of benzoic acid and sorbic acid; and / or

[0064] The second oil-soluble plugging material includes at least one of asphaltene and resin; and / or

[0065] The nanofibers include at least one of silica nanofibers and alumina nanofibers; and / or

[0066] The first pH adjuster includes at least one of sodium hydroxide, potassium carbonate, and sodium carbonate; and / or

[0067] The second corrosion inhibitor comprises at least one of cetylpyridinium bromide, tallow amine, and octadecylamine; and / or

[0068] The second surfactant includes at least one of sodium dodecylbenzene sulfonate, nano-ferroferric oxide, and nano-silicon dioxide; and / or

[0069] The second pH adjuster includes at least one of sodium hydroxide, potassium carbonate, and sodium carbonate; and / or

[0070] The polymer includes at least one of polyacrylamide and polyethylene glycol; and / or

[0071] The clay stabilizer solution is an aqueous solution with a clay stabilizer mass fraction of 5%-8%, and the clay stabilizer contains at least one of potassium chloride and ammonium chloride.

[0072] As a preferred embodiment of the present invention, the first surfactant is alkylphenol polyoxyethylene ether, the first oil-soluble plugging material is bone glue, and the first corrosion inhibitor is benzoic acid; and / or

[0073] The second oil-soluble plugging material is asphaltene, and the asphaltene is specifically rock asphalt, and the second corrosion inhibitor is hexadecylpyridinium bromide; and / or

[0074] The second surfactant is a compound of sodium dodecylbenzene sulfonate and nano-ferroferric oxide; and / or

[0075] The polymer is polyacrylamide.

[0076] Due to the interactions between different components, when the types of each component meet the above limitations, the required performance of each component can be better exerted, the plugging effect can be improved, the water content can be reduced, and the oil recovery rate can be increased.

[0077] As a preferred embodiment of the present invention, in the second surfactant, the mass ratio of sodium dodecylbenzene sulfonate and nano ferroferric oxide is (8-10): (15-18). After the operation is completed, the squeeze water absorption index can reach 1m 3 / (d·MPa) or more, 2m 3 / (d·MPa) or less, the two can synergistically improve the wettability of water on the pipe surface, reduce the water-oil interfacial tension, reduce the oil production start-up pressure, and at the same time play a good water plugging role, thereby improving oil production and quality.

[0078] As a preferred embodiment of the present invention, the preparation method of the water-soluble temporary plugging agent is: melt the first oil-soluble plugging material, then add the first surfactant and the first corrosion inhibitor thereto, and then add water or a mixture of water and the measure return fluid to obtain a water-soluble temporary plugging agent. The preparation method of the oil-soluble temporary plugging agent is: melt the second oil-soluble plugging material, then add nanofibers, the second corrosion inhibitor and the first pH regulator thereto, stir, then cool and make solid particles, and finally mix with a solvent to obtain an oil-soluble temporary plugging agent. The above method can be used to prepare a temporary plugging agent material with uniform composition, give full play to the role of each component in the temporary plugging agent, and achieve plugging and drive adjustment under the condition of less dosage.

[0079] As a preferred embodiment of the present invention, when preparing the oil-soluble temporary plugging agent, the stirring condition is 3000r / min-4000r / min, and the solvent includes at least one of white oil and kerosene. When the above conditions are met, the composition of the temporary plugging agent prepared is more uniform.

[0080] As a preferred embodiment of the present invention, with respect to an oil layer with a porosity of 5%-8% and a reservoir thickness of 4m-12m, under the first condition, the mass of water injected into the casing each time is 15m 3 -20m 3 , the mass of the oil-soluble temporary plugging agent injected into the casing each time is 1t-2t, and the reaction time is 12h-24h; under the second condition, the mass of the water-soluble temporary plugging agent injected into the oil pipe each time is 1t-2t, and the mass of the imbibition agent injected into the casing each time is 2t-3t; under the third condition, the reaction time is 12h-24h. The above-mentioned limitation on the amount of addition each time is to balance the water plugging and flooding performance. After the treatment with the above-mentioned amount of water-soluble temporary plugging agent, oil-soluble temporary plugging agent and imbibition agent, the squeezed liquid water absorption index can reach 0.8m 3 / (d·MPa)-2m 3 / (d·MPa), will not suddenly drop to too low, has good adjustment and displacement performance, and will not be difficult to reduce or require the use of a large amount of raw materials to reduce, so that the water content in the produced is low.

[0081] As a preferred embodiment of the present invention, the initial water content of the horizontal well is above 60%; the initial water content is the average water content of the produced product one month ago. When the initial water content is lower than 60%, the horizontal well may not be subjected to plugging and regulating treatment. When the initial water content is higher than this value, the graded plugging and regulating and driving method of the present invention can significantly improve the oil quality of the horizontal well.

[0082] The present application is further described in detail below in conjunction with specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed in the present application.

[0083] The following embodiments and comparative examples are all implemented in an oil layer with a formation porosity of 6% and a reservoir thickness of 8 m. The inner diameter of the casing is 124 mm, and the inner diameter of the oil pipe is 62 mm.

[0084] Example 1

[0085] An embodiment of the method for adjusting the plugging and driving of a horizontal well with a fixed pipe string of the present invention is a method for adjusting the plugging and driving of a horizontal well with a fixed pipe string of the horizontal well, which has been put into production for one month and has an initial water content of 70%, as a target well. The method for adjusting the plugging and driving of a horizontal well comprises the following steps:

[0086] S1, calculated, the water absorption index is 8m 3 / (d·MPa), inject 20t of water and 1.5t of oil-soluble temporary plugging agent into the casing, react for 12h, and calculate its squeezed liquid water absorption index, which is 3m 3 / (d·MPa);

[0087] S2, inject 2 tons of water-soluble temporary plugging agent into the oil pipe, the squeeze pressure reaches 20.5MPa, and then inject 3 tons of imbibition agent into the casing. At this time, the squeeze liquid water absorption index reaches 2.6m 3 / (d·MPa); then 1.5t of water-soluble temporary plugging agent is injected into the tubing, and the squeezing pressure reaches 22MPa. Then 2t of imbibition agent is injected into the casing, and the squeezing liquid water absorption index reaches 1.8m 3 / (d·MPa), stop injecting water-soluble temporary plugging agent and imbibition agent;

[0088] S3, add 5t of clay stabilizer aqueous solution with a clay stabilizer mass fraction of 8% into the casing, shut in the well for 24h to achieve plugging and flooding.

[0089] The pseudo-water absorption index is the ratio of the difference between the historical daily water injection volume and the liquid production volume of the horizontal well to the pressure difference.

[0090] The squeeze water absorption index is the ratio of the instantaneous liquid volume squeezed during horizontal well construction to the squeeze pressure.

[0091] Potassium chloride is used as clay stabilizer.

[0092] The water-soluble temporary plugging agent is a mixture of alkylphenol polyoxyethylene ether, bone glue, benzoic acid and water; in terms of mass fraction, its ingredients are: 20% alkylphenol polyoxyethylene ether, 15% bone glue, 8% benzoic acid, and the balance is water. After the bone glue is heated to more than 60 degrees, benzoic acid and alkylphenol polyoxyethylene ether are added respectively, and finally the backflow liquid and water are added and mixed evenly.

[0093] The oil-soluble temporary plugging agent is a mixture of rock asphalt, silicon dioxide nanofibers, sodium hydroxide, hexadecylpyridinium bromide, and white oil; in terms of mass fraction, its ingredients are: 7% rock asphalt, 20% nanofibers, 5% sodium hydroxide, 20% hexadecylpyridinium bromide, and the balance is white oil. The rock asphalt is heated to 110 degrees, and then nanofibers and hexadecylpyridinium bromide are added. Sodium hydroxide is added during stirring at a stirring rate of 3500r / min, and the mixture is cooled and formed into nanoparticles, which are finally mixed with white oil.

[0094] The absorbing agent is sodium dodecylbenzene sulfonate, nano-Fe 3 O 4 , sodium hydroxide and polyacrylamide; according to mass fraction, its ingredients are: 10% sodium dodecylbenzene sulfonate, nano-Fe 3 O 4 18%, sodium hydroxide 5%, polyacrylamide 10%, and the balance is water.

[0095] Example 2

[0096] An embodiment of the method for adjusting the plugging and driving of the fixed pipe column of a horizontal well of the present invention is used as the target well. The method uses a horizontal well with an initial water content of 70% and a production capacity of 1 month as the target well. The water absorption index is 8m 3 / (d·MPa). The difference between the plugging and flooding method and Example 1 is that the mass fraction of sodium dodecylbenzene sulfonate in the imbibition agent is 8.7%, and the nano-Fe 3 O 4 The mass fraction of water-soluble temporary plugging agent is 19.3%; in S2, 2 tons of water-soluble temporary plugging agent is injected into the oil pipe, and the squeezing pressure reaches 20.6MPa, and then 3 tons of imbibition agent is injected into the casing. At this time, the water absorption index of the squeezed liquid reaches 2.6m 3 / (d·MPa); then 2t of water-soluble temporary plugging agent is injected into the tubing, and the squeezing pressure reaches 22.1MPa. Then 2t of imbibition agent is injected into the casing, and the squeezing liquid water absorption index reaches 1.5m 3 / (d·MPa), stop injecting water-soluble temporary plugging agent and imbibition agent.

[0097] Example 3

[0098] An embodiment of the method for adjusting the plugging and driving of the fixed pipe column of a horizontal well of the present invention is used as the target well. The method uses a horizontal well with an initial water content of 70% and a production capacity of 1 month as the target well. The water absorption index is 8m 3 / (d·MPa). The difference between the plugging and flooding method and Example 1 is that the mass fraction of sodium dodecylbenzene sulfonate in the imbibition agent is 11.2%, and the nano-Fe 3 O 4The mass fraction of is 16.8%; in S2, 2 tons of water-soluble temporary plugging agent is injected into the oil pipe, the squeezing pressure reaches 20.1MPa, and then 2.5 tons of imbibition agent is injected into the casing. At this time, the water absorption index of the squeezed liquid reaches 2.5m 3 / (d·MPa); then 1.5t of water-soluble temporary plugging agent is injected into the tubing, and the squeeze pressure reaches 21.9MPa. Then 2t of imbibition agent is injected into the casing, and the squeeze liquid water absorption index reaches 2m 3 / (d·MPa), stop injecting water-soluble temporary plugging agent and imbibition agent.

[0099] Example 4

[0100] An embodiment of the method for adjusting the plugging and driving of the fixed pipe column of a horizontal well of the present invention is used as the target well. The method uses a horizontal well with an initial water content of 70% and a production capacity of 1 month as the target well. The water absorption index is 8m 3 / (d·MPa). The difference between the plugging and flooding method and Example 1 is that the mass fraction of sodium dodecylbenzene sulfonate in the imbibition agent is 7%, and the nano-Fe 3 O 4 The mass fraction is 21%; in S2, 2 tons of water-soluble temporary plugging agent is injected into the oil pipe, and the squeezing pressure reaches 20.6MPa, and then 3 tons of imbibition agent is injected into the casing. At this time, the squeezing liquid water absorption index reaches 2.8m 3 / (d·MPa); then 2t of water-soluble temporary plugging agent is injected into the tubing, and the squeezing pressure reaches 23.5MPa. Then 2t of imbibition agent is injected into the casing, and the squeezing liquid water absorption index reaches 2.2m 3 / (d·MPa), stop injecting water-soluble temporary plugging agent and imbibition agent.

[0101] Example 5

[0102] An embodiment of the method for adjusting the plugging and driving of the fixed pipe column of a horizontal well of the present invention is used as the target well. The method uses a horizontal well with an initial water content of 70% and a production capacity of 1 month as the target well. The water absorption index is 8m 3 / (d·MPa). The difference between the plugging and flooding method and Example 1 is that the mass fraction of sodium dodecylbenzene sulfonate in the imbibition agent is 14%, and the nano-Fe 3 O 4 The mass fraction is 14%; in S2, 2 tons of water-soluble temporary plugging agent is injected into the oil pipe, the squeezing pressure reaches 20.5MPa, and then 3 tons of imbibition agent is injected into the casing. At this time, the squeezing liquid water absorption index reaches 2.7m 3 / (d·MPa); then 2t of water-soluble temporary plugging agent is injected into the tubing, and the squeezing pressure reaches 21.1MPa. Then 2t of imbibition agent is injected into the casing, and the squeezing liquid water absorption index reaches 2.3m 3 / (d·MPa), stop injecting water-soluble temporary plugging agent and imbibition agent.

[0103] Example 6

[0104] An embodiment of the method for adjusting the plugging and driving of the fixed pipe column of a horizontal well of the present invention is used as the target well. The method uses a horizontal well with an initial water content of 70% and a production capacity of 1 month as the target well. The water absorption index is 8m 3 / (d·MPa). The difference between the plugging and flooding method and that of Example 1 is that the nano-Fe in the imbibition agent 3 O 4 The mass fraction is 28%; in S2, 2 tons of water-soluble temporary plugging agent is injected into the oil pipe, and the squeezing pressure reaches 20.5MPa, and then 3 tons of imbibition agent is injected into the casing. At this time, the squeezing liquid water absorption index reaches 2.9m 3 / (d·MPa); then 2t of water-soluble temporary plugging agent is injected into the tubing, and the squeezing pressure reaches 24.7MPa. Then 2t of imbibition agent is injected into the casing, and the squeezing liquid water absorption index reaches 2.5m 3 / (d·MPa), stop injecting water-soluble temporary plugging agent and imbibition agent.

[0105] Comparative Example 1

[0106] A horizontal well fixed pipe plugging and driving method, which takes a horizontal well with an initial water content of 70% and a production well that has been put into production for one month as the target well, and the simulated water absorption index is 8m 3 / (d·MPa). This method does not grade water-soluble temporary plugging agent, oil-soluble temporary plugging agent and imbibition agent into the casing and tubing, but only injects oil-soluble temporary plugging agent and imbibition agent into the casing to reduce the water absorption index. The difference from Example 2 is that 4 tons of oil-soluble temporary plugging agent are injected into the casing, the squeezing pressure reaches 24.2MPa, and then 5 tons of imbibition agent are injected into the casing. At this time, the squeezed liquid water absorption index reaches 2.6m 3 / (d·MPa).

[0107] From the above test results, it can be seen that when the dosage of temporary plugging agent and imbibition agent in comparative example 1 is the same as that in embodiment 2, the reduction rate of the squeezed liquid water absorption index is significantly lower than that of the present invention, and the cost of plugging and flooding is relatively high. 3 O 4 When the two components are used, the plugging and flooding effects are significantly better than when there is only one surfactant, and the squeeze water absorption index decreases relatively faster. In addition, when sodium dodecylbenzene sulfonate and nano-Fe 3 O 4 When the mass ratio of is (8-10): (15-18), after S2 is finished, the squeezed liquid water absorption index falls within 2m 3 / (d·MPa) or less, with excellent plugging and flooding effects.

[0108] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for adjusting plugging and driving of a horizontal well fixed pipe string, characterized in that: The horizontal well comprises a casing and an oil pipe, wherein the oil pipe is located inside the casing; The plugging and driving method comprises: Calculate the pseudo water absorption index. Under the first condition, inject water into the casing, and then inject the oil-soluble temporary plugging agent. After the reaction is completed, calculate the squeeze liquid water absorption index. When the squeeze liquid water absorption index still meets the first condition, repeat the above steps. Under the second condition, a water-soluble temporary plugging agent is injected into the oil pipe, the squeezing pressure is controlled to be 15MPa-23MPa, and then an imbibition agent is injected into the casing; when the squeezing liquid water absorption index still meets the second condition, the above steps are repeated; Under the third condition, a clay stabilizer solution is injected into the casing to react and complete plugging and flooding; The pseudo-water absorption index is the average value of the ratio of the difference between the daily water injection volume and the daily liquid production volume of the horizontal well in the first three months to the daily oil-water well pressure difference; The squeeze water absorption index is the ratio of the instantaneous liquid volume of squeezed water to the squeeze pressure during horizontal well construction; The first condition is that the pseudo water absorption index is greater than 3m 3 / (d·MPa); The second condition is that the squeeze water absorption index is less than or equal to 3m 3 / (d·MPa), greater than 2m 3 / (d·MPa); The third condition is that the squeeze water absorption index is less than or equal to 2m 3 / (d·MPa).

2. The plugging and displacement adjustment method according to claim 1, characterized in that: The water-soluble temporary plugging agent is a water-soluble microemulsion temporary plugging agent. According to the mass fraction, the water-soluble temporary plugging agent includes: 10%-20% of the first surfactant, 10%-15% of the first oil-soluble plugging material, and 5%-8% of the first corrosion inhibitor; and / or According to mass fraction, the oil-soluble temporary plugging agent includes: 4%-7% of the second oil-soluble plugging material, 15%-20% of the nanofiber, 3%-5% of the first pH regulator, and 15%-20% of the second corrosion inhibitor; and / or Calculated by mass fraction, the imbibition agent includes: 23%-28% of a second surfactant, 3%-5% of a second pH regulator, and 8%-10% of a polymer.

3. The plugging and displacement adjustment method according to claim 2, characterized in that: The first surfactant comprises at least one of alkylphenol polyoxyethylene ether, C12-18 fatty alcohol polyoxyethylene ether, and sorbitan ester; and / or The first oil-soluble plugging material includes at least one of bone glue, peach gum and natural rubber; and / or The first corrosion inhibitor comprises at least one of benzoic acid and sorbic acid; and / or The second oil-soluble plugging material includes at least one of asphaltene and resin; and / or The first pH regulator comprises at least one of sodium hydroxide, potassium carbonate and sodium carbonate; and / or The second corrosion inhibitor comprises at least one of hexadecylpyridinium bromide, tallow amine, and octadecylamine; and / or The second surfactant comprises at least one of sodium dodecylbenzene sulfonate, nano-ferroferric oxide, and nano-silicon dioxide; and / or The second pH regulator comprises at least one of sodium hydroxide, potassium carbonate and sodium carbonate; and / or The polymer includes at least one of polyacrylamide and polyethylene glycol; and / or The clay stabilizer solution is an aqueous solution with a clay stabilizer mass fraction of 5%-8%, and the clay stabilizer contains at least one of potassium chloride and ammonium chloride.

4. The plugging and driving method according to claim 3, characterized in that: The first surfactant is alkylphenol polyoxyethylene ether, the first oil-soluble plugging material is bone glue, and the first corrosion inhibitor is benzoic acid; and / or The second oil-soluble plugging material is asphaltene, the asphaltene is rock asphalt, and the second corrosion inhibitor is hexadecylpyridinium bromide; and / or The second surfactant is a compound of sodium dodecylbenzene sulfonate and nano-ferroferric oxide; and / or The polymer is polyacrylamide.

5. The plugging and driving method according to claim 4, characterized in that: In the second surfactant, the mass ratio of the sodium dodecylbenzene sulfonate to the nano-ferroferric oxide is (8-10):(15-18).

6. The plugging and driving method according to any one of claims 2 to 5, characterized in that: The preparation method of the water-soluble temporary plugging agent is: melting the first oil-soluble plugging material, then adding the first surfactant and the first corrosion inhibitor thereto, and then adding water or a mixture of water and measure return fluid to obtain the water-soluble temporary plugging agent.

7. The plugging and driving method according to any one of claims 2 to 5, characterized in that: The preparation method of the oil-soluble temporary plugging agent is: melting the second oil-soluble plugging material, then adding the nanofibers, the second corrosion inhibitor and the first pH regulator thereto, stirring, then cooling to obtain solid particles, and finally mixing with a solvent to obtain the oil-soluble temporary plugging agent.

8. The plugging and displacement adjustment method according to claim 7, characterized in that: The stirring condition is 3000r / min-4000r / min; the solvent includes at least one of white oil and kerosene.

9. The plugging and driving method according to any one of claims 1 to 5, characterized in that: For an oil layer with a formation porosity of 5%-8% and a reservoir thickness of 4m-12m, under the first condition, the mass of water injected into the casing each time is 15m 3 -20m 3 , the mass of the oil-soluble temporary plugging agent injected into the casing each time is 1t-2t, and the reaction time is 12h-24h; under the second condition, the mass of the water-soluble temporary plugging agent injected into the oil pipe each time is 1t-2t, and the mass of the imbibition agent injected into the casing each time is 2t-3t; under the third condition, the reaction time is 12h-24h.

10. The plugging and displacement adjustment method according to any one of claims 1 to 5, characterized in that: The initial water content of the horizontal well is above 60%; the initial water content is the average water content of the produced product one month before.