CN110734754A - Loss-stopping agent composition and leakage-stopping agent and preparation method and application thereof - Google Patents

Abstract

The invention relates to the field of leakage prevention and plugging of drilling fluids, and discloses a plugging agent composition, a plugging agent and a preparation method and application thereof. The lost circulation agent composition of the present invention contains biomimetic mussel adhesive, nanoclay, vinyl monomer, crosslinking agent and water. The lost circulation agent prepared by the lost circulation agent composition of the present invention is a biomimetic mussel strong adhesion polymer gel lost circulation agent, which has excellent underwater adhesion ability, anti-pollution ability and anti-pressure ability. and high temperature resistance.

Description

Loss-stopping agent composition and leakage-stopping agent and preparation method and application thereof

technical field

The invention relates to the field of leakage prevention and plugging of drilling fluids, in particular to a plugging agent composition, a plugging agent and a preparation method and application thereof.

Background technique

Loss of circulation has always been a problem that plagues field engineers around the world. The occurrence of lost circulation generally should meet the conditions that the working fluid pressure in the wellbore is greater than the pore pressure of the liquid in the formation pores, fractures or caves, and there are leakage channels and a large space for liquid accommodation in the formation. Conventional plugging materials are generally divided into four categories: particles, flakes, fibers and a mixture of the above two or more materials. Commonly used plugging methods are divided into eight categories: (1) adjusting drilling fluid performance; (2) static plugging method; (3) bridging material plugging method; (4) high fluid loss slurry plugging method; (5) temporary plugging method. plugging method; (6) chemical plugging method; (7) inorganic gel plugging method; (8) composite plugging method. Chemical plugging refers to injecting the screened chemical plugging agent into the leakage layer to form a gel to block the leakage channel. Common chemical plugging consists of PNN chemical gel, urea-formaldehyde resin, ND-1 plugging slurry, hydrolyzed polyacrylonitrile thick slurry, silicate and synthetic latex. At present, because chemical plugging needs to form gel in the formation, most of them are suitable for the process of stopping drilling and plugging.

Stop drilling and plugging work refers to stopping drilling when encountering a leakage layer, raising the drill bit, injecting plugging slurry, and holding the pump to seal the formation. This process consumes a lot of non-production time, and the plugging agent injected requires that the plugging agent cannot form gel in the wellbore, and must have good pumpability before construction. It is mostly used to solve malignant leakage or partial leakage. The plugging-while-drilling process refers to adding plugging material to the drilling fluid when encountering a leakage layer or about to encounter a leakage layer. This process does not affect drilling, but is mostly used to solve micro-miniature leakage situations.

Permeability loss is a complex situation often encountered in the drilling process. The main reason is that the formation itself has high sand content, high porosity and high permeability, and drilling fluid easily penetrates into the formation. Secondly, there are natural or induced fractures in the formation. When encountering formations with fractures, it is easy to enter the fractures and lose drilling fluid. At present, for osmotic leakage, most of the plugging materials used are fruit shells, walnut shells, acid-soluble calcium, fibers, and organic synthetic resin particles. Because the polymer gel itself has a certain viscoelasticity and strength, it can squeeze into the leakage layer when it encounters the leakage layer, and the gradation with the leakage channel is greatly reduced. It is the research hotspot of current LWD plugging agent.

At present, polymer gel LWD agents mainly include cross-linked polyacrylamide gel, polyacrylic acid gel, urea-formaldehyde resin, acrylic resin, etc. Field application shows that these materials all play a certain role, but there are also some problems, such as insufficient pressure bearing capacity and low success rate of one-time plugging. The main reason is that the adhesion ability of the plugging agent is not enough, and the anti-scouring ability after entering the leakage layer is poor, and it cannot be firmly adhered to the rock wall of the leakage layer.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a loss-stopping agent composition prepared from the leakage-stopping agent composition in order to overcome the problems of insufficient adhesion capacity, low pressure bearing capacity and poor leakage-stopping effect of the prior art. The lost circulation agent and its application in drilling leakage prevention and leakage prevention, the lost circulation agent prepared by the lost circulation agent composition of the present invention is a biomimetic mussel strong adhesion supramolecular gel lost circulation agent, which has extremely Good underwater adhesion ability, and strong anti-pollution ability, anti-pressure ability and high temperature resistance ability.

The inventors of the present invention found that most of the polymer gel plugging while drilling agents used in the prior art are independent individuals, and the plugging agents themselves do not interact with each other, so the pressure bearing capacity after plugging is low and the plugging effect is low. Difference. In order to overcome these problems, the inventors of the present invention have conducted in-depth research and found that by selecting biomimetic mussel adhesives and nanoclays, and then synthesizing cross-linked polyacrylamide composite gels by free-radical polymerization, a compound gel with The invention is completed by the polymer gel plugging agent with excellent underwater adhesion ability and strong anti-pollution ability, pressure bearing ability and high temperature resistance ability.

The reason why the polymer gel lost circulation plugging agent of the present invention has the above-mentioned excellent effect is presumed that: the present invention can enhance while drilling by introducing a biomimetic mussel adhesive rich in catechol functional groups into the polymer gel lost circulation blocking agent. The adhesion ability of the lost circulation agent in the drilling fluid, when the lost circulation agent enters the leakage layer, it can be firmly adhered to the wall surface of the leakage layer, on the one hand, the anti-flushing ability is enhanced, and on the other hand, it is prepared by the lost circulation agent composition of the invention. The surface of the plugging agent contains a large number of hydrogen bonds, and a supramolecular structure can be formed between the plugging agents, which further enhances the plugging ability and improves the formation pressure bearing capacity.

Thus, in a first aspect of the present invention, a lost circulation agent composition is provided, which comprises a biomimetic mussel adhesive, nanoclay, vinyl monomers, a crosslinking agent and water.

Preferably, relative to 100 parts by weight of water, the bionic mussel adhesive is 0.3-3 parts by weight, the nanoclay is 1-8 parts by weight, and the vinyl monomer is 3-15 parts by weight , the crosslinking agent is 0.05-8 parts by weight.

Preferably, the biomimetic mussel adhesive is one or more of gallic acid, dopamine, catechol and tannin.

Preferably, the nanoclay is magnesium aluminum silicate.

Preferably, the nanoclay is one or more of nanoclay laponite RDS, nanoclay laponite SL25, nanoclay laponiteJS and nanoclay laponite RD.

Preferably, the vinyl-based monomer is one or more of acrylic monomers and acrylamide-based monomers.

Preferably, the vinyl-based monomer is one or more of acrylamide, acrylic acid, methacrylamide, methacrylic acid and N-vinylpyrrolidone.

Preferably, the crosslinking agent is one or more of N,N-dimethylbisacrylamide, ethylene glycol dimethacrylate, 1,4-butanediol diacrylate and tetraisocyanate .

According to the second aspect of the present invention, there is provided a method for preparing a loss-stopping agent, the method comprising the steps of mixing the components of the loss-stopping agent composition of the present invention and performing a polymerization and cross-linking reaction.

Preferably, after the first mixing of the biomimetic mussel adhesive, the nanoclay and the water, the second mixing with the vinyl monomer and the crosslinking agent is performed.

Preferably, the conditions for the first mixing include: a temperature of 10-40° C. and a time of 10-24 hours.

Preferably, the conditions for the second mixing include: a temperature of 10-40° C. and a time of 5-30 min.

Preferably, the conditions for the polymerization and cross-linking reaction include: the reaction temperature is 50-70° C., and the reaction time is 4-8 h.

Preferably, the polymeric crosslinking reaction is carried out in the presence of an initiator.

Preferably, the initiator is a redox initiator or an azo initiator.

Preferably, the initiator is azobisisobutyramidine hydrochloride, azodicarbonamide, azobisisobutylimidazoline hydrochloride, azoisobutylcyanoformamide, azodicyclohexyl One or more of formonitrile, azobiscyanovaleric acid, azobisisopropylimidazoline, azobisisobutyronitrile, azobisisovaleronitrile and azobisisoheptanenitrile.

Preferably, the initiator is used in an amount of 2-30 parts by weight relative to 100 parts by weight of the vinyl monomer.

Preferably, the method further includes the step of drying the polymerized cross-linking reaction product.

According to the third aspect of the present invention, there is provided a lost circulation agent prepared by the preparation method of the present invention.

According to the fourth aspect of the present invention, the application of the lost circulation agent composition of the present invention and the lost circulation agent prepared according to the preparation method of the present invention in drilling leakage prevention and leakage blocking is provided.

Through the above technical solutions, the present invention has the following advantages.

1) The polymer gel plugging agent of the present invention has excellent underwater adhesion ability, and can effectively block leaking pores.

2) The polymer gel plugging agent of the present invention has low toxicity, environmental protection, simple production process and low cost.

3) The polymer gel plugging agent of the present invention has good compatibility and strong anti-pollution ability.

4) The polymer gel plugging agent of the present invention has strong resistance to high temperature of 180°C.

5) The polymer gel leakage plugging agent of the present invention can effectively block the sand tray leakage layer with a maximum pore radius of 50-100 mD, and has a strong pressure bearing capacity of more than 4MPa.

Detailed ways

The endpoints of ranges and any values disclosed herein are not limited to the precise ranges or values, which are to be understood to encompass values proximate to those ranges or values. For ranges of values, the endpoints of each range, the endpoints of each range and the individual point values, and the individual point values can be combined with each other to yield one or more new ranges of values that Ranges should be considered as specifically disclosed herein.

A first aspect of the present invention provides a loss-stopping agent composition, which contains a biomimetic mussel adhesive, nanoclay, vinyl-based monomers, a cross-linking agent and water.

According to the present invention, from the viewpoint of further improving the underwater adhesion ability, anti-pollution ability, pressure resistance ability and high temperature resistance ability, preferably, relative to 100 parts by weight of water, the bionic mussel adhesive is 0.3- 3 parts by weight, the nanoclay is 1-8 parts by weight, the vinyl monomer is 3-15 parts by weight, and the crosslinking agent is 0.05-8 parts by weight; more preferably, relative to 100 parts by weight water, the bionic mussel adhesive is 0.5-2 parts by weight, the nanoclay is 2-5 parts by weight, the vinyl monomer is 5-10 parts by weight, and the cross-linking agent is 0.1 -5 parts by weight.

According to the present invention, the biomimetic mussel adhesive is a catechol functional group-rich biomimetic mussel adhesive commonly used in the art. Preferably, the biomimetic mussel adhesive is one or more of gallic acid, dopamine, catechol and tannin; more preferably, the biomimetic mussel adhesive is dopamine, catechol and one or more of tannins.

According to the present invention, preferably, the nanoclay is magnesium aluminum silicate; more preferably, the nanoclay is one or more of nanoclay laponite RDS, nanoclay laponite SL25, nanoclay laponiteJS and nanoclay laponiteRD ; More preferably, the nanoclay is nanoclay laponite RD. The nanoclay laponite RD (Veegum Ultra) can be purchased from Sigma-Aldrich, for example.

According to the present invention, the vinyl monomer is preferably one or more of acrylic monomer and acrylamide monomer; more preferably C _0-6 alkyl acrylic acid and C _0-6 alkyl propylene one or more of the amides.

Examples of the vinyl-based monomers include C _0-6 alkyl acrylic acids such as acrylic acid, methacrylic acid, ethyl propionic acid, propyl acrylic acid, butyl acrylic acid, pentyl acrylic acid, and hexyl acrylic acid; acrylamide , C _0-6 alkyl acrylamides such as methacrylamide, ethyl acrylamide, propyl acrylamide, butyl acrylamide, pentyl acrylamide or hexyl acrylamide; and N-vinyl pyrrolidone and the like. Among them, one or more of acrylamide, acrylic acid, methacrylamide, methacrylic acid, and N-vinylpyrrolidone are preferable.

According to the present invention, preferably, the crosslinking agent is one of N,N-dimethylbisacrylamide, ethylene glycol dimethacrylate, 1,4-butanediol diacrylate and tetraisocyanate. one or more.

According to the second aspect of the present invention, there is provided a method for preparing a loss-stopping agent, the method comprising the steps of mixing the components of the loss-stopping agent composition of the present invention and performing a polymerization and cross-linking reaction.

According to the method of the present invention, the method of mixing the components of the lost circulation agent composition of the present invention is not particularly limited. For example, the components can be mixed together and then subjected to a polymerization crosslinking reaction; After one or two ingredients are mixed, the other ingredients are mixed together or separately. Preferably, after the first mixing of the biomimetic mussel adhesive, the nanoclay and the water, the second mixing with the vinyl monomer and the crosslinking agent is performed.

The first mixing method is preferably: mixing water with the biomimetic mussel adhesive first, and then mixing with the nanoclay. Preferably, the conditions for the first mixing include: the temperature is 10-40°C, and the time is 10-24 hours; more preferably, the conditions for the first mixing include: the temperature is 15-40°C, and the time is 15- 22 hours.

In addition, the conditions of the above-mentioned second mixing are not particularly limited as long as the vinyl-based monomer and the crosslinking agent can be sufficiently dissolved. Preferably, the conditions for the second mixing include: the temperature is 10-40°C, and the time is 5-30min; more preferably, the conditions for the second mixing include: the temperature is 15-40°C, and the time is 15-20min .

According to the method of the present invention, preferably, the conditions for the polymerization and cross-linking reaction include: the reaction temperature is 45-85° C., and the reaction time is 2-20 h; more preferably, the conditions for the polymerization and cross-linking reaction include: the reaction temperature It is 50-70 ℃, and the reaction time is 4-8h.

According to the method of the present invention, the initiator may be a redox initiator. The redox initiator can be appropriately selected from a variety of redox initiator systems that can initiate free radical polymerization, for example, the oxidant of the redox initiator can be persulfate (sodium persulfate, sodium persulfate, One or more of potassium persulfate, ammonium persulfate, etc.), hydrogen peroxide, hydroperoxide (cumene hydroperoxide), etc., the reducing agent in the oxidation-reduction initiator can be ferrous iron One or more of salts (ferrous sulfate, ferrous chloride, etc.), sulfites (sodium sulfite, sodium bisulfite, potassium sulfite, etc.), thiosulfate (sodium thiosulfate, etc.), etc. Wherein, preferably, the molar ratio of the oxidizing agent and the reducing agent in the oxidation-reduction initiator is preferably 1:1-1.5.

In addition, the initiator may also be an azo initiator. The azo initiators can be dimethyl azobisisobutyrate (trade name AIBME, V601), azobisisobutyramidine hydrochloride (trade name AIBA, V50), azodicarboxamide (trade name AIBME, V50). ADC foaming agent), azobisisobutylimidazoline hydrochloride (trade name AIBI, VA044), azoisobutylcyanoformamide (trade name CABN, V30), azodicyclohexylcarbonitrile ( Trade names ACCN, V40), azobiscyanovaleric acid (trade names ACVA, V501), azobisisopropylimidazoline (trade names AIP, VA061), azobisisobutyronitrile (trade names AIBN, V60 ), one or more of azobisisovaleronitrile (trade name AMBN, V59) and azobisisoheptanenitrile (trade name ABVN, V65).

According to the present invention, the amount of the initiator can be selected according to the amount of the vinyl monomer. Generally, the amount of the initiator is 0.1-35 parts by weight relative to 100 parts by weight of the vinyl monomer. ; Preferably, with respect to 100 parts by weight of vinyl monomers, the amount of the initiator is 2-30 parts by weight.

According to the method of the present invention, the polymeric cross-linking reaction is generally carried out under an inert atmosphere, which may be provided, for example, by one or more of nitrogen, helium, neon, argon, and the like.

According to the present invention, preferably, the method further comprises the step of drying the polymerized cross-linking reaction product. The drying aspect is not particularly limited, and various methods commonly used in the art can be used, for example, drying can be performed at 60-80° C. for 16-48 hours.

According to the third aspect of the present invention, there is provided a lost circulation agent prepared by the method of the present invention.

According to the fourth aspect of the present invention, the application of the lost circulation agent composition of the present invention and the lost circulation agent prepared according to the preparation method of the present invention in drilling leakage prevention and leakage blocking is provided.

The loss-stopping agent of the invention has excellent underwater adhesion ability, and has strong anti-pollution ability, pressure-resisting ability and high-temperature resistance ability, and is especially suitable for use as a loss-stopping agent while drilling, and can be used for drilling leakage prevention of deep water development wells plugging.

The present invention will be described in detail through the following examples, but the present invention is not limited to the following examples.

In the following examples and comparative examples, "part" means "part by weight"; dopamine and catechol were purchased from Sigma-Aldrich; tannic acid was purchased from Suzhou Huahang Chemical Technology Co., Ltd.; gallic acid was purchased from Rizhao Chengming Biotechnology Co., Ltd. Company; nanoclay laponite RD (Veegum Ultra) was purchased from Sigma-Aldrich.

Example 1

Add 0.5 part of dopamine to 100 parts of distilled water at 25°C, stir with a magnetic stirrer for 10 min, add 2 parts of nanoclay laponite RD, use a magnetic stirrer, stir at 25°C for 16h, add 5 parts of vinyls to the above mixture A monomer (specifically, acrylamide) and 0.1 part of a cross-linking agent (specifically, N,N-dimethylbisacrylamide) were stirred at 25° C. for 10 min until the monomer and the cross-linking agent were fully dissolved. Then pour the mixture into a three-necked flask, pass nitrogen for 30 min, use a water bath to heat to 60°C, use an electric mixer to heat while stirring, and after the temperature of the mixture reaches 60°C, add 0.1 part of an initiator (specifically azobisisobutylene) amidine hydrochloride), a white gel product was obtained after 8 h of reaction. After cooling, take out the gel for washing, place it in an oven to dry at 70°C for 16 hours to obtain a white solid product, and pulverize the solid product into particles to obtain bionic mussel polymer gel plugging agent A1.

Example 2

Add 1 part of dopamine to 100 parts of distilled water at 25°C, stir with a magnetic stirrer for 12 minutes, add 2.5 parts of nanoclay laponite RD, use a magnetic stirrer, stir at 25°C for 18h, add 7.5 parts of vinyls to the above mixture A monomer (specifically, acrylamide) and 2.5 parts of a cross-linking agent (specifically, N,N-dimethylbisacrylamide) were stirred at 25° C. for 15 minutes until the monomer and the cross-linking agent were fully dissolved. Then pour the mixture into a three-necked flask, pass nitrogen for 30 min, use a water bath to heat to 60°C, use an electric mixer to heat while stirring, and when the temperature of the mixture reaches 60°C, add 1 part of an initiator (specifically azobisisobutylene) amidine hydrochloride), a white gel product was obtained after 8 h of reaction. After cooling, take out the gel for washing, place it in an oven to dry at 70° C. for 16 hours to obtain a white solid product, and pulverize the solid product into particles to obtain bionic mussel polymer gel plugging agent A2.

Example 3

Add 5 parts of dopamine to 100 parts of distilled water at 25°C, stir with a magnetic stirrer for 15 minutes, add 5 parts of nanoclay laponite RD, use a magnetic stirrer, stir at 25°C for 20h, add 10 parts of vinyls to the above mixture A monomer (specifically, acrylamide) and 5 parts of a cross-linking agent (specifically, N,N-dimethylbisacrylamide) were stirred at 25° C. for 20 min until the monomer and the cross-linking agent were fully dissolved. Then pour the mixture into a three-necked flask, pass nitrogen for 30 min, use a water bath to heat to 60°C, use an electric mixer to heat while stirring, and when the temperature of the mixture reaches 60°C, add 3 parts of an initiator (specifically azobisisobutylene) amidine hydrochloride), a white gel product was obtained after 8 h of reaction. After cooling, take out the gel for washing, place it in an oven to dry at 70° C. for 16 hours to obtain a white solid product, and pulverize the solid product into particles to obtain bionic mussel polymer gel plugging agent A3.

Example 4

Add 0.5 part of catechol to 100 parts of distilled water at 25°C, stir with a magnetic stirrer for 10 min, add 2 parts of nanoclay laponite RD, use a magnetic stirrer, stir at 25°C for 16h, add 5 parts of ethylene to the above mixture Base monomer (specifically, acrylamide) and 0.1 part of cross-linking agent (specifically, N,N-dimethylbisacrylamide), and stir at 25° C. for 10 min until the monomer and the cross-linking agent are fully dissolved. Then pour the mixture into a three-necked flask, pass nitrogen for 30 min, use a water bath to heat to 60°C, use an electric mixer to heat while stirring, and after the temperature of the mixture reaches 60°C, add 0.1 part of an initiator (specifically azobisisobutylene) amidine hydrochloride), a white gel product was obtained after 8 h of reaction. After cooling, take out the gel for washing, place it in an oven to dry at 70° C. for 16 hours to obtain a white solid product, and pulverize the solid product into particles, which is the biomimetic mussel polymer gel plugging agent A4.

Example 5

Add 1 part of catechol to 100 parts of distilled water at 25°C, stir with a magnetic stirrer for 12 minutes, add 2.5 parts of nanoclay laponite RD, use a magnetic stirrer, stir at 25°C for 18h, add 7.5 parts of ethylene to the above mixture Basic monomer (specifically, acrylamide), 2.5 parts of cross-linking agent (specifically, N,N-dimethylbisacrylamide), and stirred at 25° C. for 15 minutes until the monomer and the cross-linking agent were fully dissolved. Then pour the mixture into a three-necked flask, pass nitrogen for 30 min, use a water bath to heat to 60°C, use an electric mixer to heat while stirring, and when the temperature of the mixture reaches 60°C, add 1 part of an initiator (specifically azobisisobutylene) amidine hydrochloride), a white gel product was obtained after 8 h of reaction. After cooling, take out the gel for washing, place it in an oven to dry at 70°C for 16 hours to obtain a white solid product, and pulverize the solid product into particles to obtain bionic mussel polymer gel plugging agent A5.

Example 6

Add 5 parts of catechol to 100 parts of distilled water at 25°C, stir with a magnetic stirrer for 15 minutes, add 5 parts of nanoclay laponite RD, use a magnetic stirrer, stir at 25°C for 20h, add 10 parts of the above mixture to the above mixture A vinyl monomer (specifically, acrylamide) and 5 parts of a cross-linking agent (specifically, N,N-dimethylbisacrylamide) were stirred at 25° C. for 20 min until the monomer and the cross-linking agent were fully dissolved. Then pour the mixture into a three-necked flask, pass nitrogen for 30 min, use a water bath to heat to 60°C, use an electric mixer to heat while stirring, and when the temperature of the mixture reaches 60°C, add 3 parts of an initiator (specifically azobisisobutylene) amidine hydrochloride), a white gel product was obtained after 8 h of reaction. After cooling, take out the gel for washing, place it in an oven to dry at 70° C. for 16 hours to obtain a white solid product, and pulverize the solid product into particles to obtain bionic mussel polymer gel plugging agent A6.

Example 7

Add 0.5 part of tannic acid to 100 parts of distilled water at 25°C, stir with a magnetic stirrer for 10 minutes, add 2 parts of nanoclay laponite RD, use a magnetic stirrer, stir at 25°C for 16h, add 5 parts to the above mixture A vinyl monomer (specifically, acrylamide) and 0.1 part of a cross-linking agent (specifically, N,N-dimethylbisacrylamide) were stirred at 25° C. for 10 min until the monomer and the cross-linking agent were fully dissolved. Then pour the mixture into a three-necked flask, pass nitrogen for 30 min, use a water bath to heat to 60°C, use an electric mixer to heat while stirring, and after the temperature of the mixture reaches 60°C, add 0.1 part of an initiator (specifically azobisisobutylene) amidine hydrochloride), a white gel product was obtained after 8 h of reaction. After cooling, take out the gel for washing, place it in an oven to dry at 70° C. for 16 hours to obtain a white solid product, and pulverize the solid product into particles, which is the bionic mussel polymer gel plugging agent A7.

Example 8

Add 1 part of tannic acid to 100 parts of distilled water at 25°C, stir with a magnetic stirrer for 12 minutes, add 2.5 parts of nanoclay laponite RD, use a magnetic stirrer, stir at 25°C for 18h, add 7.5 parts of the above mixture to the above mixture A vinyl monomer (specifically, acrylamide) and 2.5 parts of a cross-linking agent (specifically, N,N-dimethylbisacrylamide) were stirred at 25° C. for 15 minutes until the monomer and the cross-linking agent were fully dissolved. Then pour the mixture into a three-necked flask, pass nitrogen for 30 min, use a water bath to heat to 60°C, use an electric mixer to heat while stirring, and when the temperature of the mixture reaches 60°C, add 1 part of an initiator (specifically azobisisobutylene) amidine hydrochloride), a white gel product was obtained after 8 h of reaction. After cooling, take out the gel for washing, place it in an oven to dry at 70°C for 16 hours to obtain a white solid product, and pulverize the solid product into particles to obtain bionic mussel polymer gel plugging agent A8.

Example 9

Add 5 parts of tannic acid to 100 parts of distilled water at 25°C, stir with a magnetic stirrer for 15 minutes, add 5 parts of nanoclay laponite RD, use a magnetic stirrer, stir at 25°C for 20h, add 10 parts to the above mixture A vinyl monomer (specifically, acrylamide) and 5 parts of a cross-linking agent (specifically, N,N-dimethylbisacrylamide) were stirred at 25° C. for 20 min until the monomer and the cross-linking agent were fully dissolved. Then pour the mixture into a three-necked flask, pass nitrogen for 30 min, use a water bath to heat to 60°C, use an electric mixer to heat while stirring, and when the temperature of the mixture reaches 60°C, add 3 parts of an initiator (specifically azobisisobutylene) amidine hydrochloride), a white gel product was obtained after 8 h of reaction. After cooling, take out the gel for washing, place it in an oven to dry at 70°C for 16 hours to obtain a white solid product, and pulverize the solid product into particles to obtain bionic mussel polymer gel plugging agent A9.

Example 10

Add 0.5 part of gallic acid to 100 parts of distilled water at 25°C, stir with a magnetic stirrer for 10 min, add 2 parts of nanoclay laponite RD, use a magnetic stirrer, stir at 25°C for 16h, add 5 parts of ethylene to the above mixture Base monomer (specifically, acrylamide) and 0.1 part of cross-linking agent (specifically, N,N-dimethylbisacrylamide), and stir at 25° C. for 10 min until the monomer and the cross-linking agent are fully dissolved. Then pour the mixture into a three-necked flask, pass nitrogen for 30 min, use a water bath to heat to 60°C, use an electric mixer to heat while stirring, and after the temperature of the mixture reaches 60°C, add 0.1 part of an initiator (specifically azobisisobutylene) amidine hydrochloride), a white gel product was obtained after 8 h of reaction. After cooling, take out the gel for washing, place it in an oven to dry at 70° C. for 16 hours to obtain a white solid product, and pulverize the solid product into particles to obtain bionic mussel polymer gel plugging agent A10.

Example 11

Add 1 part of gallic acid to 100 parts of distilled water at 25°C, stir with a magnetic stirrer for 12 minutes, add 2.5 parts of nanoclay laponite RD, use a magnetic stirrer, stir at 25°C for 18h, add 7.5 parts of ethylene to the above mixture Basic monomer (specifically, acrylamide), 2.5 parts of cross-linking agent (specifically, N,N-dimethylbisacrylamide), and stirred at 25° C. for 15 minutes until the monomer and the cross-linking agent were fully dissolved. Then pour the mixture into a three-necked flask, pass nitrogen for 30 min, use a water bath to heat to 60°C, use an electric mixer to heat while stirring, and when the temperature of the mixture reaches 60°C, add 1 part of an initiator (specifically azobisisobutylene) amidine hydrochloride), a white gel product was obtained after 8 h of reaction. After cooling, take out the gel for washing, place it in an oven to dry at 70°C for 16 hours to obtain a white solid product, and pulverize the solid product into particles to obtain bionic mussel polymer gel plugging agent A11.

Example 12

Add 5 parts of gallic acid to 100 parts of distilled water at 25°C, stir with a magnetic stirrer for 15 min, add 5 parts of nanoclay laponite RD, use a magnetic stirrer, stir at 25°C for 20h, add 10 parts of ethylene to the above mixture Base monomer (specifically, acrylamide) and 5 parts of cross-linking agent (specifically, N,N-dimethylbisacrylamide), and stir at 25° C. for 20 min until the monomer and the cross-linking agent are fully dissolved. Then pour the mixture into a three-necked flask, pass nitrogen for 30 min, use a water bath to heat to 60°C, use an electric mixer to heat while stirring, and when the temperature of the mixture reaches 60°C, add 3 parts of an initiator (specifically azobisisobutylene) amidine hydrochloride), a white gel product was obtained after 8 h of reaction. After cooling, the gel was taken out for washing, placed in an oven for drying at 70°C for 16 hours to obtain a white solid product, and the solid product was pulverized into particles to obtain bionic mussel polymer gel plugging agent A12.

Comparative Example 1

2.5 parts of nanoclay laponite RD at 25°C was stirred at 25°C for 18h using a magnetic stirrer, then 7.5 parts of vinyl monomers (specifically acrylamide) and 2.5 parts of cross-linking agent (specifically, acrylamide) were added to the above mixture. N,N-dimethylbisacrylamide), stirred at 25 °C for 15 min until the monomer and crosslinking agent were fully dissolved. Then pour the mixture into a three-necked flask, pass nitrogen for 30 min, use a water bath to heat to 60°C, use an electric mixer to heat while stirring, and when the temperature of the mixture reaches 60°C, add 1 part of an initiator (specifically azobisisobutylene) amidine hydrochloride), a white gel product was obtained after 8 h of reaction. After cooling, take out the gel for washing, place it in an oven to dry at 70° C. for 16 hours to obtain a white solid product, and pulverize the solid product into particles, which is the plugging agent D1.

Comparative Example 2

Add 0.5 part of dopamine to 100 parts of distilled water at 25°C, stir with a magnetic stirrer for 10 min, add 5 parts of vinyl monomer (specifically N,N-dimethylbisacrylamide), 0.1 part of crosslinking agent ( Specifically, acrylamide) was stirred at 25° C. for 10 min until the monomer and cross-linking agent were fully dissolved. Then pour the mixture into a three-necked flask, pass nitrogen for 30 min, use a water bath to heat to 60°C, use an electric mixer to heat while stirring, and after the temperature of the mixture reaches 60°C, add 0.1 part of an initiator (specifically azobisisobutylene) amidine hydrochloride), a white gel product was obtained after 8 h of reaction. After cooling, take out the gel for washing, place it in an oven to dry at 70° C. for 16 hours to obtain a white solid product, and pulverize the solid product into particles to obtain bionic mussel polymer gel plugging agent A2.

Test Example 1

The method for evaluating the plugging effect of permeable strata in deep water drilling is implemented by using a high temperature and high pressure water loss instrument combined with a sand tray. The upper part of the kettle body is provided with a rotary air inlet valve, the lower part is provided with a rotary liquid discharge valve, and the upper air inlet valve is connected to a nitrogen cylinder.

The formation process of the sand disk is as follows: take a core with known permeability (specifically, the permeability is 1000mD), and use a lathe to cut it into a cylindrical sand disk with a diameter of 61±0.5mm and a length of 5±0.5mm.

Using the above-mentioned permeable sand pan to evaluate the effect of permeable leakage and plugging of deepwater drilling, the following steps are included in sequence:

(1) Load the sand disc with known permeability into the kettle body, and tighten the lower cover and lower valve stem;

(2) Turn the kettle body upside down, pour the prepared drilling fluid and plugging agent from the upper part, tighten the upper cover and the upper valve stem and put it into the heating jacket of the high temperature and high pressure water loss instrument;

(3) Install the nitrogen gas inlet valve. Open the main valve of the nitrogen bottle, adjust the pressure reducing valve to 100psi, and open the upper valve stem intake valve;

(4) Open the lower rotary discharge valve, immediately press the stopwatch to record the time and instantaneous leakage, and then increase the pressure at a rate of 100 psi/2min (with 100 psi as the pressure step, and pressurize for 2 minutes after pressure), and record different pressures The accumulated leakage under the pressure is 700psi, then the pressure is stabilized for 2min, and the total leakage is recorded;

(5) After the plugging is completed, first close the rotary drain valve, then close the nitrogen bottle valve, loosen the pressure reducing valve, open the pressure relief valve on the top cover of the leak plugging instrument to release air, remove the kettle body, and unscrew the top cover. Take out the drilling fluid and plugging agent in the kettle body, take out the sand tray, and clean the plugging test device.

Among them, the instantaneous leakage refers to the amount of mud that is lost instantaneously when the lower rotary drain valve is opened under a pressure of 100 psi. The accumulated leakage refers to the accumulated leakage after the ball valve is opened, the pressure is increased to 700psi at 100psi/2min, and then the pressure is stabilized for 2min. The pressure bearing capacity of the plugging layer refers to the pressure rising process from 100 psi to 700 psi and the pressure stabilization period of 700 psi, if there is no sudden enlargement of the leakage, it is considered that the pressure bearing capacity is greater than or equal to 700 psi; If the pressure loss suddenly increases, the pressure is considered to be the pressure bearing pressure of the plugging layer.

Using the plugging agents obtained in Examples 1-12 and Comparative Examples 1-2, the plugging effect was evaluated according to the above method, wherein the drilling fluid formulation: 4 wt % base slurry + 0.5 wt % thickener + 1 wt % Cutting agent + 1 wt% fluid loss reducer + barite (density 1.4 g/cm ³ ). Among them, 4% by weight of bentonite and 0.5% by weight of sodium carbonate were added into deionized water, stirred and aged for 16 hours to obtain base pulp, the tackifier was polyacrylamide, the shearing agent was modified starch, and the fluid loss control agent was polyanionic cellulose. Barite is barium sulfate. In addition, the addition amount of the lost circulation agent in the test is 3% by weight of the drilling fluid, and the test results are shown in Table 1.

Table 1

Instantaneous loss/mL Cumulative lost volume/mL Pressure/MPa Example 1 2 5 6 Comparative Example 1 15 35 2 Comparative Example 2 10 twenty two 3 Example 2 2 4 6.4 Example 3 1 4 6.8 Example 4 5 15 5 Example 5 5 14 5 Example 6 4 12 5 Example 7 4.8 14 5 Example 8 4.6 13 5 Example 9 4.6 13 5 Example 10 6.4 16 4 Example 11 6 15 4 Example 12 6 14 4

As can be seen from Table 1, Examples 1-12 are the lost circulation agent prepared by adopting the lost circulation agent composition of the present invention, and its blocking effect and anti-pressure ability are significantly better than those of the comparative example without biomimetic mussel adhesive. 1 and Comparative Example 2 without nanoclay laponiteRD. In addition, in all tests, the sealing effect of Comparative Example 1 was the worst, mainly because the biomimetic mussel adhesive was not added during the synthesis process, and the synthesized product did not have strong adhesion and could not form strong adhesion in the leakage channel. Adhesive blocking layer.

Test case 2

The lost circulation agents obtained in Example 1, Example 4, Example 7 and Comparative Examples 1-2 were added to the drilling fluid respectively (the amount of the lost circulation blocking agent added was 3% by weight of the drilling fluid), and then added in different After aging at temperature for 16 hours, the evaluation of the sealing effect of the sand disc was carried out in the same manner as in Test Example 1. The results are shown in Table 2. In addition, the drilling fluid formulation was the same as that of Test Example 1.

Table 2

It can be seen from Table 2 that the loss-stopping agent prepared by using the loss-stopping agent composition of the present invention can resist a temperature of 180° C. and has a good plugging effect. In addition, the addition of nanoclay to the lost circulation agent can effectively improve the temperature resistance of the lost circulation agent. Leakage agent temperature resistance.

The preferred embodiments of the present invention have been described above in detail, however, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, a variety of simple modifications can be made to the technical solutions of the present invention, including the combination of various technical features in any other suitable manner. These simple modifications and combinations should also be regarded as the content disclosed in the present invention. All belong to the protection scope of the present invention.

Claims (13)

1, kinds of plugging agent composition, characterized in that, the composition contains bionic mussel adhesive, nano clay, vinyl monomer, cross-linking agent and water.

2. The composition as in claim 1, wherein the biomimetic mussel adhesive is 0.3-3 parts by weight, the nanoclay is 1-8 parts by weight, the vinyl monomer is 3-15 parts by weight, and the cross-linking agent is 0.05-8 parts by weight, relative to 100 parts by weight of water.

3. The composition of claim 1, wherein the biomimetic mussel adhesive is or more of gallic acid, dopamine, catechol, and tannic acid.

4. The composition of any of claims 1-3, wherein the nanoclay is magnesium aluminum silicate;

preferably, the nanoclay is or more of nanoclay laponite RDS, nanoclay laponite SL25, nanoclay laponite js, and nanoclay laponite RD.

5. The composition of any of claims 1-3, wherein the vinylic monomer is or more of an acrylic monomer and an acrylamide monomer;

preferably, the vinyl monomer is or more of acrylamide, acrylic acid, methacrylamide, methacrylic acid and N-vinyl pyrrolidone.

6. The composition of any of claims 1-3, wherein the crosslinker is one or more of N, N-dimethylbisacrylamide, ethylene glycol dimethacrylate, 1, 4-butanediol diacrylate, and tetraisocyanate .

A process for preparing kinds of leak stopping agent, which comprises mixing the components of the leak stopping agent composition as claimed in any of claims 1-6 and carrying out polymerization crosslinking reaction.

8. The method of claim 7, wherein the biomimetic mussel adhesive, the nanoclay and water are mixed before being mixed with the vinyl-based monomer and cross-linking agent for a second time;

preferably, the mixing conditions include a temperature of 10-40 deg.C and a time of 10-24 hours;

preferably, the conditions of the second mixing include: the temperature is 10-40 deg.C, and the time is 5-30 min.

9. The method of claim 7, wherein the conditions of the polymeric crosslinking reaction comprise: the reaction temperature is 50-70 ℃, and the reaction time is 4-8 h.

10. The method of claim 7, wherein the polymeric crosslinking reaction is carried out in the presence of an initiator;

preferably, the initiator is an oxidation-reduction initiator or an azo-type initiator;

preferably, the initiator is or more of azobisisobutyramidine hydrochloride, azobisformamide, azobisisobutylimidazoline hydrochloride, azobisisobutyronitrile formamide, azobiscyclohexylcarbonitrile, azobiscyanovaleric acid, azobisdiisopropylimidazoline, azobisisobutyronitrile, azobisisovaleronitrile, and azobisisoheptonitrile;

preferably, the initiator is used in an amount of 2 to 30 parts by weight, relative to 100 parts by weight of the vinyl-based monomer.

11. The method of claim 7, further comprising the step of drying the polymerized cross-linked reaction product.

12, kinds of plugging agents, which is characterized by being prepared by the preparation method of any of claims 7-11.

13. A plugging agent composition as defined in any of claims 1-6 and a plugging agent prepared by the preparation method as defined in any of claims 7-11, which are applied to leak-proof and plugging of a drilling well.