Annular pressure well cementation sealing liquid system and preparation and use methods thereof

Abstract

The invention discloses an annulus pressure well cementation sealing liquid system and preparation and use methods thereof, the annulus pressure well cementation sealing liquid system comprises the following components by weight: 50-70 parts of a polymer viscous plugging material, 15-30 parts of a hydratable framework material, 5-15 parts of a special dispersion material, and 20-30 parts of clear water. The high-molecular viscous plugging material is used as a main material and compounded with the hydratable framework material and the special dispersing material for the system to form an annulus pressure well cementation sealing liquid system, and the high-molecular viscous plugging material of the system effectively plugs an annulus fluid channeling medium before the sealing liquid forms strength; the hydratable framework material is hydrated to form strength which can effectively provide fluid channeling section well section supporting strength, the treatment measure effect of an annulus pressure well in the Changqing oil field is improved, and the problem that due to the fact that an existing superfine silicate system is poor in plugging effect, a well mouth is continuously pressurized is effectively solved.

Description

Technical Field

[0001] The invention belongs to the technical field of oil and gas field well repair, and in particular relates to an annular zone well-killing cementing sealing liquid system and a preparation and use method thereof. Background Art

[0002] In recent years, with the increasing demand for natural gas and the deepening of exploration and development work, the underground geological conditions and wellbore structure have become more and more complex, and the problems of annular space pressure or wellhead gas blowby after cementing have become more and more prominent. Most of the treatments are regular detection, periodic pressure release, well repair and cement squeezing.

[0003] However, it is very difficult to control annular pressure (including gas leakage at the wellhead). Although it is easy to find abnormal annular pressure in oil and gas wells on the ground, it is difficult to determine the fluid leakage point, which makes it impossible to take targeted remedial measures. At present, the main means of controlling annular pressure is to overhaul oil and gas wells and squeeze cement into the annulus to re-seal fluid channels such as micro-cracks in the cement annulus. However, the cracks in the cement annulus are very small, and the materials containing the solid phase cannot fully enter and fill them. The construction of squeezing cement into the annulus is difficult and dangerous, and the success rate is very low.

[0004] Therefore, although the workover operation can directly act on the well section where the annulus seal fails, it is costly and is not economically viable if it is at the end of the well production. If the annulus pressure is caused by the crossflow of gas outside the pipe, the treatment technology is difficult and the cost is high. It is usually necessary to perforate or mill off the production casing, and then seal the crossflow channel by squeezing cement. However, squeezing cement or perforating usually destroys the overall sealing of the production casing and causes other crossflow channels. Due to the low success rate and high operating cost, perforating or milling casing and squeezing cement are usually considered the last technical measures. It can be seen that the conventional workover method for remedying annular pressure is costly and dangerous, which will cause great danger to construction personnel, damage equipment, and cause blowouts or ejected materials to harm the environment. Sometimes the cost and danger of workover exceed the danger of annular pressure in gas wells. The existing ultra-fine silicate cement squeeze-sealing system has weak interface viscosity and poor interlayer sealing ability. After the measures, there is still a phenomenon of continuous pressure gas emission at the wellhead, which cannot meet the needs of long-term development of wells with annular pressure.

[0005] It can be seen that the existence of the annular pressure problem has become a huge engineering and technical problem faced by oil and gas fields at home and abroad. Severe annular pressure or annular air breakthrough not only makes it impossible to smoothly implement subsequent drilling, perforating, workover, testing and production increase measures, but also poses a threat to the well construction cycle and the safe development of oil and gas. The research and development of a new sealant system with excellent performance has become the key to efficiently solving the annular pressure problem.

[0006] At present, there are few sealant systems for managing annular pressure. Publication (announcement) No. CN106761568B discloses a method for managing annular pressure in gas wells, which is to supplement the annular pressure of gas wells by injecting an annular protection fluid with a density greater than the gas production into the annular pressure of the gas well from the ground, thereby preventing the gas production in the gas well production string from leaking into the annular pressure of the gas well, and reducing the annular pressure of the gas well in the annular pressure gas well. The method involves an annular protection fluid that can remove the pressure in the annular pressure of the gas well without stopping the production of the gas well, and keep it in a stable state for a long time, thereby improving the safety of the production operation of the natural gas well. However, the method requires long-term detection of the state of the annular protection fluid, adjustment of its performance and irregular replenishment, which consumes manpower and material resources.

[0007] Publication (Announcement) No.: CN112341999A, on October 23, 2020, disclosed an epoxy resin cementing plugging system and its preparation method and application, wherein the plugging system contains the following components in parts by mass: 100 parts of epoxy resin, 5-25 parts of curing agent A, 5-30 parts of curing agent B, 2-40 parts of curing agent C, and 0-200 parts of density regulator. The plugging system of this invention is epoxy resin, which is used for new well construction, and the system cannot be cured at low temperatures, and the resin has a high consistency before curing. No special resin dispersion material is designed, and the technical requirements of high-pressure extrusion sealing cannot be met. In addition, the resin rheology dispersion adjustment material used in this invention is combined with a hydratable skeleton material. Its (ultrafine cement) itself has a large hydration heat release that can promote the curing of the resin. The resin cures and fills the pores of the ultrafine material to form a three-dimensional structure with high viscosity and high strength of the cured body, which promotes the sealing of the annulus of the annulus pressure well.

[0008] Publication (Announcement) No. CN113930200A discloses a sealant and its preparation method and application. The sealant includes a composite resin, a curing agent, a toughening agent and a viscosity reducer. The sealant is squeezed from the ground annulus into the annulus of the oil and gas well and cured to seal the micro-cracks in the cement ring, which can achieve effective sealing of the annulus of the oil and gas well to solve the problem of casing annulus pressure. However, the patent does not use a hydratable skeleton material, and it is also unable to form strength in a short time under low temperature conditions. It does not reflect the promoting effect of the resin and the curable skeleton material, nor does it mention the specific on-site use method of the system, and the scope of use is limited. Summary of the invention

[0009] Aiming at the technical problems of well killing in the annular zone of Changqing Oilfield, the present invention aims to provide an annular zone well killing cementing sealing liquid system and its preparation and use method. By compounding polymer viscous plugging materials, hydratable skeleton materials and system-specific dispersed materials, the annular channeling medium of the annular zone well killing is effectively plugged, and the plugged well section is given a high-strength support effect, solving the problem of long-term effective development of oil and gas wells with annular zone pressure.

[0010] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0011] The invention provides an annular zone well-killing cementing sealing liquid system, which comprises the following components in parts by weight: 50-70 parts of polymer viscous plugging material, 15-30 parts of hydratable skeleton material, 5-15 parts of special dispersing material and 20-30 parts of clean water.

[0012] As a further preferred embodiment, the polymer viscous plugging material comprises modified bisphenol F epoxy resin and amide amine curing agent, and the mass ratio of the modified bisphenol F epoxy resin to the amide amine curing agent is 100:(5-10).

[0013] Preferably, the density of the modified bisphenol F epoxy resin is 1.15-1.25 g / cm 3 , solid content 60%, particle size 200-220nm.

[0014] As a further preferred embodiment, the amide amine curing agent is prepared from dimethylformamide and diethylformamide in a mass ratio of 2:1.

[0015] As a further preferred embodiment, the hydratable skeleton material comprises the following components in parts by weight: 87-93 parts of ultrafine cement, 5-8 parts of ultrafine calcium carbonate, and 2-5 parts of anhydrous sodium silicate.

[0016] Preferably, the mesh size of the ultrafine cement is 1550-1850 mesh, and the mesh size of the ultrafine calcium carbonate is 1025-1250 mesh.

[0017] As a further preferred embodiment, the dedicated dispersing material is one or a mixture of butyl glycidyl ether, phenyl glycidyl ether, ethylene glycol diglycidyl ether, and 1,4-butanediol diglycidyl ether.

[0018] The present invention also provides a method for preparing an annular zone well-killing cementing sealing liquid system, comprising the following steps:

[0019] (1) 50-70 parts by weight of a high molecular weight viscous plugging material, 5-15 parts by weight of a special dispersing material and 20-30 parts by weight of clean water are uniformly mixed to form a mixed solution for standby use;

[0020] (2) Weigh 15-30 parts by weight of a hydratable skeleton material for later use;

[0021] (3) Under low-speed stirring conditions of 3800 r / min-4200 r / min, the hydratable skeleton material prepared in step (2) is added to the mixed solution obtained in step (1) within 15 seconds, and then stirred for 35-45 seconds under high-speed stirring conditions of 7800 r / min-8200 r / min to obtain an annular zone well-pressing cementing sealing liquid system.

[0022] The present invention also provides a method for using an annular zone well-killing cementing sealing liquid system, which comprises the following steps:

[0023] S1. Use a large amount of clean water to wash the well until the wellbore is filled with clean water;

[0024] S2. Carry out water squeeze test from annulus B

[0025] 0.1-0.2m 3 / min displacement, pressurize the B annulus through the operating machine at the wellhead, and when the pressure rises to the maximum test extrusion pressure P1, stop the pump to observe the B annulus pressure and pump pressure, record the pumping volume and pressure drop, and record the maximum pumping volume as V1;

[0026] S3. Lower the cement retainer to the plugging section, circulate the wellbore to complete the cement retainer seat sealing, lift the insert pipe to leave the cement retainer position, pump in an annulus pressure well cementing sealing liquid system with a volume of 2V1, control the wellhead pressure to be less than the maximum test extrusion pressure P1, lift the insert pipe and circulate until the inlet and outlet water colors are consistent, pull out the drill to a safe position at the wellhead, shut down the well and wait for solidification.

[0027] According to a specific implementation of the present invention, the maximum test extrusion pressure P1 is the minimum value between the rated working pressure of the wellhead equipment and 80% of the internal pressure resistance of the surface casing.

[0028] The present invention also provides the use of any one of the above annular zone well-killing cementing sealing liquid systems or the annular zone well-killing cementing sealing liquid system prepared by the above method in oil and gas well repair.

[0029] The present invention has the following beneficial effects:

[0030] 1. The annular zone well-killing cementing sealing liquid system involved in the present invention is mainly composed of polymer viscous plugging materials, which are compounded with hydratable skeleton materials and system-specific dispersed materials to form an annular zone well-killing cementing sealing liquid system. The polymer viscous plugging materials in this system can effectively seal the annular crossflow medium before the sealing liquid forms strength. The hydration strength of the hydratable skeleton material can effectively provide support strength for the crossflow section, thereby improving the effect of the annular zone well-killing management measures in Changqing Oilfield.

[0031] 2. The method for using the annular zone well-killing cementing sealing liquid system of the present invention increases the amount of sealing liquid entering the plugged well section under the premise of ensuring safe construction, thereby ensuring the annular zone well-killing treatment effect.

[0032] 3. The annular zone well-killing cementing sealing liquid system of the present invention is resistant to strong acid and alkali corrosion, with a density of 1.25-1.50g / cm 3 The curing time is adjustable and controllable in the temperature range of 30℃-120℃, and the sedimentation stability is less than 0.02g / cm 3 .

[0033] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the preferred embodiments of the present invention are described in detail as follows. DETAILED DESCRIPTION

[0034] The content of the present invention can be further understood by combining the following detailed description of the preferred implementation method of the present invention and the embodiments included. Unless otherwise stated, all technical and scientific terms used in this article have the same meaning as those of ordinary skill in the art to which the present invention belongs. If the definition of a specific term disclosed in the prior art is inconsistent with any definition provided in the present invention, the definition of the term provided in the present invention shall prevail.

[0035] In order to solve the annulus pressure problem of oil and gas wells and improve the effect of annulus pressure well control measures, in a typical embodiment of the present invention, an annulus pressure well cementing sealing liquid system is provided, comprising the following components in parts by weight: 50-70 parts of polymer viscous plugging material, 15-30 parts of hydratable skeleton material, 5-15 parts of special dispersing material, and 20-30 parts of clean water.

[0036] In order to make the curing speed adjustable and the curing process non-exothermic, in a specific embodiment of the present invention, the polymer viscous plugging material includes modified bisphenol F epoxy resin and amide amine curing agent, and preferably, the mass ratio of the modified bisphenol F epoxy resin and the amide amine curing agent is 100: (5-10).

[0037] Preferably, the density of the modified bisphenol F epoxy resin is 1.15-1.25 g / cm 3 , solid content 60%, particle size 200-220nm. Within this particle size range, the modified bisphenol F epoxy resin can be combined with the amidoamine curing agent, and the two can be cured under construction conditions to achieve the required curing strength.

[0038] In a preferred embodiment, the amide-amine curing agent is prepared from dimethylformamide and diethylformamide in a mass ratio of 2:1.

[0039] In a preferred embodiment, the hydratable skeleton material comprises the following components by weight: 87-93 parts of ultrafine cement, 5-8 parts of ultrafine calcium carbonate, and 2-5 parts of anhydrous sodium silicate. The hydration strength of the hydratable skeleton material of the present invention can effectively provide support strength for the crossflow section.

[0040] In a preferred embodiment, the mesh size of the ultrafine cement is 1550-1850 mesh, and the mesh size of the ultrafine calcium carbonate is 1025-1250 mesh. Within this particle size range, the combination of the hydratable skeleton material and the modified bisphenol F epoxy resin can achieve the required construction fluidity and exothermic temperature.

[0041] In order to provide effective dilution for the modified bisphenol F epoxy resin and achieve construction fluidity, the special dispersing material of the present invention is preferably a mixture of one or more of butyl glycidyl ether, phenyl glycidyl ether, ethylene glycol diglycidyl ether, and 1,4-butanediol diglycidyl ether.

[0042] In a second typical embodiment of the present invention, a method for preparing an annular zone well-killing cementing sealing fluid system is provided, comprising the following steps:

[0043] (1) 50-70 parts by weight of a high molecular weight viscous plugging material, 5-15 parts by weight of a special dispersing material and 20-30 parts by weight of clean water are mixed uniformly to form a mixed solution for standby use;

[0044] (2) Weigh 15-30 parts by weight of a hydratable skeleton material for later use;

[0045] (3) Under the low-speed stirring condition of 3800r / min-4200r / min, the hydratable skeleton material prepared in step (2) is added to the mixed solution obtained in step (1) within 15s, and then the mixture is continuously stirred for 30-40s under the high-speed stirring condition of 7800r / min-8200r / min to obtain the annular zone well-killing cementing sealing liquid system. The present invention mainly uses polymer viscous plugging materials, compound hydratable skeleton materials and system-specific dispersing materials to form an annular zone well-killing cementing sealing liquid system. The polymer viscous plugging materials in this system effectively plug the annular crossflow medium before the sealing liquid forms strength. The hydration strength of the hydratable skeleton material can effectively provide the support strength of the crossflow section, improve the effect of the annular zone well-killing treatment measures in Changqing Oilfield, and effectively reduce the problem of continuous wellhead pressure caused by the poor plugging effect of the existing ultrafine silicate system.

[0046] In a third typical embodiment of the present invention, a method for using an annular zone well-killing cementing sealing fluid system is provided, comprising the following steps:

[0047] S1. Backwash the well until the wellbore is filled with clean water;

[0048] S2. Carry out water squeeze test from the B annulus (i.e. the annular space between the production casing and the inner technical casing)

[0049] 0.1-0.2m 3 / min displacement, pressurize the B annulus through the operating machine at the wellhead, and when the pressure rises to the maximum test extrusion pressure P1, stop the pump to observe the B annulus pressure and pump pressure, record the pumping volume and pressure drop, and record the maximum pumping volume as V1;

[0050] S3. Lower the cement retainer to the plugging section, circulate the wellbore to complete the cement retainer seat sealing, lift the insert pipe to leave the cement retainer position, pump in an annulus pressure well cementing sealing liquid system with a volume of 2V1, and the extrusion volume is V1. Control the wellhead pressure to be less than the maximum test extrusion pressure P1, lift the insert pipe and circulate until the inlet and outlet water colors are consistent, pull out the drill to a safe position at the wellhead, shut down the well and wait for solidification.

[0051] Preferably, the maximum test extrusion pressure P1 is the minimum value between the rated working pressure of the wellhead equipment and 80% of the internal pressure resistance of the surface casing.

[0052] The method for using the annular zone well-killing cementing sealing liquid system increases the amount of sealing liquid (i.e. the annular zone well-killing cementing sealing liquid system) entering the plugged well section under the premise of ensuring safe construction, thereby ensuring the annular zone well-killing treatment effect.

[0053] The present invention also provides the use of any of the above annular zone well-killing cementing sealing liquid systems in oil and gas well repair.

[0054] The annular zone well killing cementing sealing fluid system is resistant to strong acid and alkali corrosion, with a density of 1.25-1.46g / cm 3 The curing time is adjustable and controllable in the temperature range of 30℃-120℃, and the sedimentation stability is less than 0.02g / cm 3 , 24h strength 45-55MPa, bonding strength 2.9-3.5MPa, permeability 0; shrinkage rate 0; elastic modulus 2.5-3.8GPa.

[0055] The present invention will be further described below in conjunction with embodiments:

[0056] Example 1

[0057] This embodiment relates to an annular zone well-killing cementing sealing fluid system, comprising the following components in parts by weight:

[0058] 70 parts of polymer viscous plugging material, 20 parts of clean water, 10 parts of hydratable skeleton material, and 5 parts of special dispersing material.

[0059] The preparation method of the annular zone well killing cementing sealing fluid system is as follows:

[0060] (1) Weigh 70 parts of polymer viscous plugging material, 20 parts of clean water, and 5 parts of special dispersing material to form a mixed solution and place it in a corrugated can;

[0061] (2) Weighing 10 parts of hydratable framework material as a solid phase mixture;

[0062] (3) adding the solid phase mixture obtained in step (2) to the mixed solution obtained in step (1) within 15 seconds at a low speed of 4000 r / min, and then continuously stirring at a high speed of 8000 r / min for 35 seconds to obtain an annular zone well-pressing cementing sealing liquid system.

[0063] The main properties of the annular zone well-killing cementing sealing liquid system of this embodiment are: strong acid and alkali corrosion resistance, density 1.25g / cm 3 The curing time is adjustable and controllable in the temperature range of 30℃-120℃, and the sedimentation stability is less than 0.02g / cm 3 , 24h compressive strength 55MPa, bonding strength 3.5MPa, permeability 0; shrinkage rate 0; elastic modulus 2.5GPa.

[0064] The on-site use method of the annular zone well killing cementing sealing fluid system of this embodiment is as follows:

[0065] (1) Wash the well with a large flow rate for at least two weeks to ensure that the wellbore is filled with clean water;

[0066] (2) Calculate the ground suction volume using clean water

[0067] Squeeze injection from annulus B and conduct clean water squeeze injection test: displacement 0.1m / min, wellhead pressure to 5MPa-10MPa-P1MPa, stop pump to observe annulus B pressure and pump pressure, record pumping volume and pressure drop, record maximum pumping volume as V1m 3 ; P1 is the maximum test extrusion pressure, which is the minimum value of the rated working pressure of the wellhead equipment and 80% of the internal pressure resistance of the surface casing;

[0068] (3) A sealing fluid with a volume of 2.5V1 (i.e., annular zone well-killing cementing sealing fluid system) is prepared on the ground for standby use;

[0069] Lower the cement retainer to the plugging section, circulate the wellbore to complete the cement retainer seat sealing, lift the insert pipe to leave the cement retainer position, pump in a plugging agent with a volume of 2V1 (i.e., annular zone wellbore cementing sealing liquid system) with an extrusion volume of V1, control the maximum squeezing pressure at the wellhead to be less than P1, lift the insert pipe and circulate until the water color at the inlet and outlet is consistent, pull out the drill to a safe position at the wellhead, shut down the well and wait for solidification.

[0070] Embodiment 2:

[0071] This embodiment relates to an annular zone well-killing cementing sealing fluid system, comprising the following components in parts by weight:

[0072] 60 parts of polymer viscous plugging material, 25 parts of clean water, 15 parts of hydratable skeleton material, and 10 parts of special dispersing material.

[0073] The preparation method of the annular zone well killing cementing sealing fluid system is as follows:

[0074] (1) Weigh 60 parts of polymer viscous plugging material, 25 parts of clean water, and 10 parts of special dispersing material to form a mixed solution and place it in a corrugated can;

[0075] (2) Weighing 15 parts of hydratable framework material as a solid phase mixture;

[0076] (3) adding the solid phase mixture obtained in step (2) to the mixed solution obtained in step (1) within 15 seconds at a low rotation speed of 3800 r / min, and then continuously stirring at a high rotation speed of 7800 r / min for 40 seconds to obtain an annular zone well-pressing cementing sealing liquid system.

[0077] The main properties of the annular zone well-killing cementing sealing liquid system of this embodiment are: strong acid and alkali corrosion resistance, density 1.35g / cm 3 The curing time is adjustable and controllable in the temperature range of 30℃-120℃, and the sedimentation stability is less than 0.02g / cm 3 , 24h strength 50MPa, bonding strength 3MPa, permeability 0; shrinkage rate 0; elastic modulus 3.2GPa.

[0078] The on-site use method of the annular zone well killing cementing sealing fluid system of this embodiment is as follows:

[0079] (1) Wash the well with a large flow rate for at least two weeks to ensure that the wellbore is filled with clean water;

[0080] (2) Carry out water injection test from annulus B:

[0081] The displacement is 0.2m3 / min, the wellhead pressure is increased to 5MPa-10MPa-P1MPa, the pump is stopped to observe the B annulus pressure and pump pressure, and the pumping volume and pressure drop are recorded. The maximum pumping volume is recorded as V1 (unit: m 3 ) ; P1 is the maximum test extrusion pressure, which is the minimum value of the rated working pressure of the wellhead equipment and 80% of the internal pressure resistance of the surface casing;

[0082] (3) A sealing fluid with a volume of 2.5V1 (i.e., annular zone well-killing cementing sealing fluid system) is prepared on the ground for standby use;

[0083] Lower the cement retainer to the plugging section, circulate the wellbore to complete the cement retainer seat sealing, lift the insert pipe to leave the cement retainer position, pump in a plugging agent with a volume of 2V1 (i.e., annular zone wellbore cementing sealing liquid system) with an extrusion volume of V1, control the maximum squeezing pressure at the wellhead to be less than P1, lift the insert pipe and circulate until the water color at the inlet and outlet is consistent, pull out the drill to a safe position at the wellhead, shut down the well and wait for solidification.

[0084] Embodiment 3:

[0085] This embodiment relates to an annular zone well-killing cementing sealing fluid system, comprising the following components in parts by weight:

[0086] 55 parts of polymer viscous plugging material, 30 parts of clean water, 20 parts of hydratable skeleton material, and 15 parts of special dispersing material.

[0087] The preparation method of the annular zone well killing cementing sealing fluid system is as follows:

[0088] (1) Weigh 55 parts of polymer viscous plugging material, 30 parts of clean water, and 15 parts of special dispersing material to form a mixed solution and place it in a corrugated can;

[0089] (2) Weighing 20 parts of hydratable framework material as a solid phase mixture;

[0090] (3) adding the solid phase mixture obtained in step (2) to the mixed solution obtained in step (1) within 15 seconds at a low rotation speed of 4200 r / min, and then continuously stirring at a high rotation speed of 8200 r / min for 30 seconds to obtain an annular zone well-pressing cementing sealing liquid system.

[0091] The main properties of the annular zone well-killing cementing sealing fluid system of this embodiment are: strong acid and alkali corrosion resistance, density 1.46g / cm 3 The curing time is adjustable and controllable in the temperature range of 30℃-120℃, and the sedimentation stability is less than 0.02g / cm 3 , 24h compressive strength 45MPa, bonding strength 2.9MPa, permeability 0; shrinkage rate 0; elastic modulus 3.8GPa.

[0092] The on-site use method of the annular zone well killing cementing sealing fluid system of this embodiment is as follows:

[0093] (1) Wash the well with a large flow rate for at least two weeks to ensure that the wellbore is filled with clean water;

[0094] (2) Carry out water injection test from annulus B:

[0095] The displacement is 0.1m3 / min, the wellhead pressure is increased to 5MPa-10MPa-P1MPa, the pump is stopped to observe the B annulus pressure and pump pressure, and the pumping volume and pressure drop are recorded. The maximum pumping volume is recorded as V1 (unit: m3 ) ; P1 is the maximum test extrusion pressure, which is the minimum value of the rated working pressure of the wellhead equipment and 80% of the internal pressure resistance of the surface casing;

[0096] (3) A sealing fluid with a volume of 2.5V1 (i.e., annular zone well-killing cementing sealing fluid system) is prepared on the ground for standby use;

[0097] Lower the cement retainer to the plugging section, circulate the wellbore to complete the cement retainer seat sealing, lift the insert pipe to leave the cement retainer position, pump in a plugging agent with a volume of 2V1 (i.e., annular zone wellbore cementing sealing liquid system) with an extrusion volume of V1, control the maximum squeezing pressure at the wellhead to be less than P1, lift the insert pipe and circulate until the water color at the inlet and outlet is consistent, pull out the drill to a safe position at the wellhead, shut down the well and wait for solidification.

[0098] In the above examples 1-3, the density, compressive strength, bonding strength and other performance tests of the annular zone well-killing cementing sealing liquid system were carried out in accordance with the specification "Oil Well Cement Test Method" (GB / T 19139-2012). The agitator involved in the experiment was a constant speed agitator of CHANDLER 3260 model produced by CHANDLER Company of the United States, the digital liquid density meter was a digital density meter of YMS1-5 model produced by Qingdao Haitongda Special Instrument Factory, the high temperature curing box was a high temperature curing box of OWC-118 model produced by the Institute of Applied Technology of Shenyang Aerospace University, the pressure testing machine was a microcomputer fully automatic pressure testing machine of WHY-300 / 10 model produced by Shanghai Hualong Testing Instrument Co., Ltd., and the cement stone permeability analyzer was a cement stone permeability tester of CTE3020 model produced by Shi Defu International Co., Ltd. of the United States. The implementation conditions not specified are usually the conditions in conventional experiments.

[0099] The above description is only a preferred embodiment of the present invention, which is merely illustrative of the present invention and does not limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made by ordinary technicians in this field to the technical solution of the present invention should fall within the scope of protection determined by the claims of the present invention.

Claims

1. An annular zone well killing cementing sealing liquid system, characterized in that: The invention comprises the following components in parts by weight: 50-70 parts of high molecular viscosity plugging material, 15-30 parts of hydratable skeleton material, 5-15 parts of special dispersing material and 20-30 parts of clean water.

2. The annular zone well killing cementing sealing liquid system according to claim 1, characterized in that: The polymer viscous plugging material comprises modified bisphenol F epoxy resin and amide amine curing agent, and the mass ratio of the modified bisphenol F epoxy resin to the amide amine curing agent is 100:(5-10).

3. The annular zone well killing cementing sealing liquid system according to claim 2, characterized in that: The density of the modified bisphenol F epoxy resin is 1.15-1.25 g / cm 3 , solid content 60%, particle size 200-220nm.

4. The annular zone well killing cementing sealing liquid system according to claim 2, characterized in that: The amide-amine curing agent is prepared by mixing dimethylformamide and diethylformamide in a mass ratio of (2-5):

1.

5. The annular zone well killing cementing sealing liquid system according to claim 1, characterized in that: The hydratable skeleton material comprises the following components, calculated by weight: 87-93 parts of ultrafine cement, 5-8 parts of ultrafine calcium carbonate, and 2-5 parts of anhydrous sodium silicate.

6. The annular zone well killing cementing sealing liquid system according to claim 5, characterized in that: The mesh number of the ultrafine cement is 1550-1850 meshes, and the mesh number of the ultrafine calcium carbonate is 1025-1250 meshes.

7. The annular zone well killing cementing sealing liquid system according to claim 1, characterized in that: The special dispersing material is one or a mixture of butyl glycidyl ether, phenyl glycidyl ether, ethylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether.

8. A method for preparing an annular zone well-killing cementing sealing liquid system, characterized in that: The following steps are involved: (1) 50-70 parts by weight of a high molecular weight viscous plugging material, 5-15 parts by weight of a special dispersing material and 20-30 parts by weight of clean water are uniformly mixed to form a mixed solution for standby use; (2) Weigh 15-30 parts by weight of a hydratable skeleton material for later use; (3) Under low-speed stirring conditions of 3800 r / min-4200 r / min, the hydratable skeleton material prepared in step (2) is added to the mixed solution obtained in step (1) within 15 seconds, and then stirred for 35-45 seconds under high-speed stirring conditions of 7800 r / min-8200 r / min to obtain an annular zone well-pressing cementing sealing liquid system.

9. A method for using an annular zone well-killing cementing sealing liquid system, characterized in that: The following steps are involved: S1. Use a large amount of clean water to wash the well until the wellbore is filled with clean water; S2. Carry out water squeeze test from annulus B 0.1-0.2m 3 / min displacement, pressurize the B annulus through the operating machine at the wellhead, and when the pressure rises to the maximum test extrusion pressure P1, stop the pump to observe the B annulus pressure and pump pressure, record the pumping volume and pressure drop, and record the maximum pumping volume as V1; S3. Lower the cement retainer to the plugging section, circulate the wellbore to complete the cement retainer seat sealing, lift the insert pipe to leave the cement retainer position, pump in an annulus pressure well cementing sealing liquid system with a volume of 2V1, control the wellhead pressure to be less than the maximum test extrusion pressure P1, lift the insert pipe and circulate until the inlet and outlet water colors are consistent, pull out the drill to a safe position at the wellhead, shut down the well and wait for solidification.

10. The method for using the annular zone well killing cementing sealing liquid system as claimed in claim 9, characterized in that: The maximum test extrusion pressure P1 is the minimum value between the rated working pressure of the wellhead equipment and 80% of the internal pressure resistance of the surface casing.