阅读说明：本技术 一种高含硫气井油套环空堵剂 (High-sulfur-content gas well oil sleeve annular plugging agent ) 是由 李智慧 张庆生 黄雪松 罗沿予 谭肖 赵国瑜 何文斌 董琴刚 于 2019-10-12 设计创作，主要内容包括：本发明属于油田化学技术领域,具体涉及一种高含硫气井油套环空堵剂。该高含硫气井油套环空堵剂,以质量份计,由以下原料组成：树脂基体20-40份、固化剂5-20份、稀释剂3-15份、增韧剂1-10份,密度调节剂1-10份,固化剂为脂环胺和/或芳香胺。本发明的高含硫气井油套环空堵剂在90-130℃固化时间都能保持在3h以上,远大于现有堵剂的固化时间,并且,本发明通过在堵剂体系中加入密度调节剂,使堵剂体系的密度大于环空保护液的密度,能够保证堵剂到达环空底部后在环空保护液中不散失。本发明的堵剂通过注入到油套环空底部在气井温度下固化形成环形封堵段塞实现环空堵漏,能够解决高含硫气井油套环空底部封隔器渗漏问题。(The invention belongs to the technical field of oilfield chemistry, and particularly relates to an oil casing annulus plugging agent for a high-sulfur-content gas well. The high-sulfur-content gas well oil sleeve annulus plugging agent comprises the following raw materials in parts by mass: 20-40 parts of resin matrix, 5-20 parts of curing agent, 3-15 parts of diluent, 1-10 parts of toughening agent and 1-10 parts of density regulator, wherein the curing agent is alicyclic amine and/or aromatic amine. The annular plugging agent of the high-sulfur-content gas well oil sleeve can be kept for more than 3 hours at the curing time of 90-130 ℃, which is much longer than the curing time of the existing plugging agent, and the density of the plugging agent system is made to be higher than that of the annular protection liquid by adding the density regulator into the plugging agent system, so that the plugging agent is ensured not to be lost in the annular protection liquid after reaching the bottom of the annulus. The plugging agent disclosed by the invention is injected into the annular bottom of the oil sleeve and is cured at the temperature of the gas well to form an annular plugging section plug so as to realize annular plugging, and the problem of leakage of a packer at the annular bottom of the oil sleeve of the high-sulfur-content gas well can be solved.)

1. The high-sulfur-content gas well oil casing annulus plugging agent is characterized by comprising the following raw materials in parts by mass: 20-40 parts of resin matrix, 5-20 parts of curing agent, 3-15 parts of diluent, 1-10 parts of toughening agent and 1-10 parts of density regulator, wherein the curing agent is alicyclic amine and/or aromatic amine.

2. The high sulfur content gas well oil casing annulus plugging agent as recited in claim 1 wherein said resin matrix is bisphenol a epoxy, ortho-cresol novolac epoxy, bisphenol a novolac epoxy, or phenol novolac epoxy.

3. The high sulfur content gas well oil casing annulus blocking agent as claimed in claim 1 wherein the curing agent is at least two selected independently from alicyclic amine or aromatic amine.

4. The high-sulfur-content gas well oil casing annulus blocking agent as claimed in claim 3, wherein the curing agent is two of 3-aminomethyl-3, 5, 5-trimethylcyclohexyldiamine, 4 '-diaminodiphenyl sulfone, 4' -diaminodiphenyl ether, 2,4, 6-tris (dimethylaminomethyl) phenol, and 3,3 '-diethyl-4, 4' -diaminodiphenylmethane.

5. The high sulfur containing gas well oil casing annulus plugging agent of claim 1 wherein the diluent is dibutyl phthalate, di-n-octyl phthalate or diallyl phthalate.

6. The high sulfur containing gas well oil casing annulus plugging agent of claim 1 wherein the toughening agent is liquid polybutadiene or liquid nitrile rubber.

7. The high-sulfur-content gas well oil casing annulus blocking agent as claimed in claim 1, wherein the density regulator is sodium montmorillonite, silica powder or ground calcium carbonate which is surface-modified by silane coupling agent.

8. The high-sulfur-content gas well oil casing annulus blocking agent as claimed in claim 7, wherein the silane coupling agent is gamma-methacryloxypropyltrimethoxysilane, gamma-methacryloxypropyltriisopropoxysilane or gamma- (2, 3-epoxypropoxy) propyltrimethoxysilane.

Technical Field

The invention belongs to the technical field of oilfield chemistry, and particularly relates to an oil casing annulus plugging agent for a high-sulfur-content gas well.

Background

High sulfur gas field gas well (H)₂10-15% of S, 90-130 ℃, 25-35 MPa of formation pressure and 5000-6000 m of well depth) adopts a production string containing a permanent packer, an oil pipe is made of G3-125 alloy, the oil sleeve annulus is provided with the permanent packer, the upper sleeve part of the permanent packer is made of TP110SS sulfur-resistant steel, and the annular space protective fluid filled in the oil sleeve annulus protects the pipe from being corroded. The high-sulfur-content gas well annulus protection fluid is water-based fluid and consists of organic acid salt, imidazoline quaternary ammonium salt, quaternary ammonium salt type cationic surfactant, isoascorbic acid alkali metal salt and water, wherein the pH value is 10-12, and the density range is 1.03-1.15 g/cm³. Along with the production process of a gas field, problems of annular protection liquid leakage, abnormal casing pressure, hydrogen sulfide monitoring of the oil casing annulus and the like occur due to leakage at the bottom of the oil casing annulus of a part of the well, and the hydrogen sulfide generates stress corrosion cracking and electrochemical corrosion on an oil casing annulus anti-sulfur steel casing pipe, a casing pipe head and the like above a permanent packer, so that potential safety hazards are brought to the production of the gas field.

The method for solving the annular leakage of the high-sulfur-content gas well mainly comprises the steps of lowering a packer again after the operation of moving a tubular column and sleeve milling and fishing, permanently sealing a well, periodically supplementing annular protection liquid, stopping leakage of a leakage part and the like. After the sleeve milling and fishing operation, the packer is put in again, and the pipe column needs to be moved for permanently sealing the well, and the operation cost is high; the annular space protection liquid is added regularly, so that only a short protection effect can be achieved; the chemical plugging agent with high temperature resistance, high density, high strength and moderate curing speed is adopted for plugging the leakage part, and the chemical plugging agent is matched with a proper filling process to perform chemical plugging on the leakage part, so that the cost is low and the effect is good.

The chemical plugging is to form bonding cross-linking by utilizing intermolecular force of a polymer on an interface to play a role in plugging, mainly comprises a polymer plugging agent, a silicate plugging agent, a resin plugging agent and the like, wherein the polymer plugging agent mainly comprises polyacrylamide, polyacrylic acid or a multipolymer and the like, and the polymer plugging agent has small bonding strength and poor acid gas corrosion resistance; the silicate plugging agent is a mixture of various cements, lime and the like, has poor alkali resistance, cannot be solidified in annular protection liquid, and cannot meet the requirement of annular plugging of a high-sulfur-content gas well. The resin plugging agent mainly comprises phenolic resin, furfuryl alcohol resin, epoxy resin and the like, wherein the phenolic resin is poor in alkali resistance, easy to be corroded by alkali liquor and not suitable for being used in an alkali annulus protection liquid environment, the furfuryl alcohol resin is good in heat resistance and water resistance, has excellent resistance to acid, alkali and organic solution, but is high in low-temperature curing speed and cannot meet the filling process requirement of the plugging agent; the epoxy resin plugging agent can improve the curing strength, acid and alkali resistance and acid and gas corrosion resistance of the epoxy resin plugging agent by optimizing synthetic raw materials, improving a synthetic method, optimizing different curing agents, adjusting the proportion of the curing agents and the like.

The Chinese patent application CN103113841A discloses a preparation method of a strong acid resistant epoxy resin rapid plugging agent, the plugging agent consists of A, B components, and the component A comprises the following raw materials in percentage by mass: 50-80% of epoxy resin, 5-20% of toughening agent and 5-20% of filler, wherein the component B comprises the following raw materials in percentage by mass: 10-50% of curing agent, 5-25% of coupling agent, 1-10% of accelerator and 1-15% of filler. According to the rapid adhesive type leak stopping method, the A, B two components are mixed at normal temperature, can be rapidly cured within 1-5 min, has excellent strong acid resistance after being cured, has high adhesion to metal, and is suitable for rapid adhesive type leak stopping when equipment such as pipelines, tank bodies and flanges of strong acid media leak. However, the plugging agent provided by the invention is added into the annular protection liquid for too fast curing time, can be cured at normal temperature, is not cured when being injected to the bottom of the oil sleeve annulus, and cannot be used for plugging the leakage at the bottom of the oil sleeve annulus of the high-sulfur-content gas field.

The Chinese patent application CN106367047A discloses a water environment time-delay consolidation leakage-stopping paste for well drilling, which consists of two components A and B in a weight ratio of A to B being 4: 1-9: 1; the component A comprises the following components in parts by weight: 60-80 parts of multi-component resin, 5-15 parts of flow pattern regulator and 5-35 parts of auxiliary material, wherein the multi-component resin comprises the following components in parts by weight: 20-25 parts of modified furfural resin, 20-25 parts of modified epoxy resin and 20-30 parts of modified vinyl resin; the component B comprises the following components in parts by weight: 5-15 parts of initiator, 5-25 parts of cross-linking agent, 10-20 parts of flow pattern regulator and 40-80 parts of inert material. The organic paste can not flow freely, but can be plastically deformed under pressure, can be solidified in a water environment, can be solidified for adjustable time for solidification at different temperatures, has the strength of more than or equal to 20MPa after 24 hours of solidification, and can solve the problem that the leakage layers, water layers, particularly the leakage layers of flowing water, and the like at different temperatures are difficult to judge and are difficult to successfully stop leakage. However, the plugging agent is paste, has too high viscosity and cannot be injected into the bottom of the annulus through a filling process.

The existing plugging agent has the defect of short curing time, and can not meet the requirement of long curing time of the plugging agent for annular bottom plugging of an oil sleeve of a high-sulfur-content gas well.

Disclosure of Invention

The invention aims to solve the problems that the existing resin plugging agent has short curing time in a high-temperature environment and cannot be used for plugging the bottom of the oil sleeve annulus of a high-sulfur-content gas well, and aims to provide the high-sulfur-content gas well oil sleeve annulus plugging agent which can prolong the curing time for plugging the leakage of a packer at the bottom of the oil sleeve annulus of the high-sulfur-content gas well, has high density and can be conveniently injected into the bottom of the annulus.

In order to achieve the aim, the technical scheme of the high-sulfur-content gas well oil casing annular plugging agent provided by the invention is as follows:

the high-sulfur-content gas well oil casing annulus plugging agent comprises the following raw materials in parts by mass: 20-40 parts of resin matrix, 5-20 parts of curing agent, 3-15 parts of diluent, 1-10 parts of toughening agent and 1-10 parts of density regulator, wherein the curing agent is alicyclic amine and/or aromatic amine.

The oil sleeve annulus plugging agent with the prolonged curing time is obtained by adding the curing agent into a high-performance resin system, the curing time of the oil sleeve annulus plugging agent for the high-sulfur-containing gas well can be kept above 3h at 90-130 ℃, which is much longer than that of the existing plugging agent, the heat resistance, the mechanical property and the corrosion resistance of a cured product can be improved by adding the alicyclic amine or the aromatic amine, the two curing agents can be cured under the heating condition and do not react with a resin matrix under the normal temperature condition, and the raw materials of the plugging agent can be uniformly mixed before being injected. The aromatic amine in the present invention is a primary amine, a secondary amine, a tertiary amine or a polyamine having one or more benzene rings in the molecule. In addition, the density regulator is added into the plugging agent system, so that the density of the plugging agent system is higher than that of the annular protection liquid, and the plugging agent can be ensured not to be dispersed in the annular protection liquid after reaching the bottom of the annulus. The plugging agent disclosed by the invention is injected into the annular bottom of the oil sleeve and is cured at the temperature of the gas well to form an annular plugging section plug so as to realize annular plugging, and the problem of leakage of a packer at the annular bottom of the oil sleeve of the high-sulfur-content gas well can be solved.

As an improvement on the scheme, the resin matrix is bisphenol A epoxy resin, o-cresol novolac epoxy resin, bisphenol A novolac epoxy resin or phenol novolac epoxy resin, and the resin can form a cured product with a compact structure and stable chemical properties with an alicyclic amine and/or aromatic amine curing agent.

In a modification of the above embodiment, the curing agents are at least two kinds and are independently selected from alicyclic amines or aromatic amines, for example, the curing agents may be two or more kinds of alicyclic amines, two or more kinds of aromatic amines, or at least one kind of alicyclic amines and at least one kind of aromatic amines. The addition of two or more curing agents can control the curing temperature of the plugging agent. Preferably, the curing agent is selected from two of 3-aminomethyl-3, 5, 5-trimethylcyclohexyldiamine (also known as isophoronediamine), 4 '-diaminodiphenyl sulfone, 4' -diaminodiphenyl ether, 2,4, 6-tris (dimethylaminomethyl) phenol, and 3,3 '-diethyl-4, 4' -diaminodiphenylmethane.

In order to adjust the viscosity of the annular blocking agent system so as to be injected into the bottom of the annulus through a filling process and serve as a solvent for a curing reaction, the diluent is dibutyl phthalate, di-n-octyl phthalate or diallyl phthalate. Meanwhile, the phthalate ester diluent also has a certain toughening effect.

In order to improve the mechanical property of the solidified annular plugging agent and improve the compression resistance of the solidified annular plugging agent, the toughening agent is selected from liquid polybutadiene or liquid nitrile rubber.

The density regulator can be selected from common filler substances such as sodium montmorillonite, silica micropowder and ground calcium carbonate, and is used for improving the binding performance of the density regulator with a resin matrix, a curing agent and the like and improving the dispersibility and compatibility of the density regulator in the annular blocking agent, wherein the density regulator is silane coupling agent surface modified sodium montmorillonite, silica micropowder or ground calcium carbonate.

Preferably, the silane coupling agent is a gamma-methacryloxypropyltrimethoxysilane coupling agent, a gamma-methacryloxypropyltriisopropoxysilane coupling agent or a gamma- (2, 3-glycidoxy) propyltrimethoxysilane coupling agent.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting.

In the following examples, bisphenol A epoxy resins were obtained from Henan Hui energy resins, Inc., models of CYD-128, DER332, etc., o-cresol novolac epoxy resins were obtained from Kai green Bignonian chemical Co., Ltd, models of CYDCN-200, CYDCN-205, CYDCN-208, etc., bisphenol A novolac epoxy resins were obtained from Wuxi Guangxi Chemicals Co., Ltd, models of E-55, E-51, E-44, E-42, etc., phenol novolac epoxy resins were obtained from Wuxi Guangxi Chemicals Co., Ltd, models of F-51, F-48, F-44, etc.

The preparation method of the surface modification density regulator in the following examples is as follows: weighing 15 parts by mass of density regulator particles before modification, adding 1000 parts by mass of water-ethanol (the volume ratio of water to ethanol is 1:20) mixed solution, stirring for 10min at normal temperature, then ultrasonically dispersing for 20min by using an ultrasonic cleaner to obtain uniform suspension, adding 10 parts by mass of silane coupling agent into the uniform suspension, stirring uniformly, continuing to perform ultrasonic treatment for 10min, transferring the mixture into a 250mL three-neck flask provided with a reflux condenser tube and a force-increasing electric stirrer, and stirring and reacting for 6h at the water bath temperature of 80 ℃. And (3) centrifugally separating the reacted slurry at normal temperature at 10000r/min by using a desk-top high-speed centrifuge, ultrasonically dispersing and centrifugally separating the separated particles for three times by using an absolute ethyl alcohol solution, placing the particles separated for the last time in a vacuum drying box, and performing vacuum drying at 80 ℃ for 24 hours to obtain the prepared surface-modified density regulator.

In examples 1 to 3, the density adjuster particles before modification were each a sodium montmorillonite particle, a fine silica powder particle, and a ground calcium carbonate particle, and the silane coupling agents used for modification were each γ -methacryloxypropyltrimethoxysilane, γ -methacryloxypropyltriisopropoxysilane, and γ - (2, 3-epoxypropoxy) propyltrimethoxysilane.

Example 1

Adding 5 parts of dibutyl phthalate diluent into 25 parts of bisphenol A epoxy resin (model: CYD-128), stirring for 10min to obtain a uniform solution, adding 2 parts of 4,4' -diaminodiphenyl sulfone, 8 parts of 3-aminomethyl-3, 5, 5-trimethylcyclohexylamine curing agent and 3 parts of liquid polybutadiene toughening agent, continuously stirring to obtain the uniform solution, finally adding 5 parts of silane coupling agent modified sodium-based montmorillonite particles, stirring to obtain a uniformly mixed solution to obtain the high-sulfur-content gas well oil sleeve annulus plugging agent, and injecting the plugging agent into the bottom of the annulus at the empty position of the oil sleeve by a pipe insertion method to realize plugging by curing.

Example 2

Adding 5 parts of di-n-octyl phthalate diluent into 30 parts of o-cresol formaldehyde epoxy resin (model: CYDCN-200), stirring for 10min to obtain a uniform solution, adding 4 parts of 4,4 '-diaminodiphenyl sulfone, 4 parts of 4,4' -diaminodiphenyl ether curing agent and 3 parts of liquid nitrile rubber toughening agent, continuously stirring to obtain the uniform solution, finally adding 6 parts of silane coupling agent modified silicon micropowder particles, stirring to obtain a uniformly mixed solution, thus obtaining the high-sulfur-content gas well oil sleeve annulus plugging agent, and injecting the plugging agent into the bottom of the annulus at the empty position of an oil sleeve by a pipe insertion method to realize plugging.

Example 3

Adding 5 parts of diallyl phthalate diluent into 30 parts of bisphenol A novolac epoxy resin (model: E-51), stirring to obtain a uniform solution, adding 2 parts of 2,4, 6-tris (dimethylaminomethyl) phenol, 8 parts of 3,3 '-diethyl-4, 4' -diaminodiphenylmethane curing agent and 5 parts of liquid polybutadiene toughening agent, continuously stirring to obtain the uniform solution, finally adding 8 parts of silane coupling agent modified heavy calcium carbonate particles, stirring to obtain a uniformly mixed solution to obtain the high-sulfur-content gas well oil casing annulus plugging agent, and injecting the plugging agent into the bottom of the annulus at the empty position of the oil casing by a pipe inserting method to cure so as to realize plugging.

Examples 4 to 8

Examples 4 to 8 were conducted in the same manner as in examples 1 to 3, and the raw material composition in each example was as shown in Table 1 below, wherein the type of the phenol novolac epoxy resin in example 4 was F-51, the type of the bisphenol A novolac epoxy resin in example 5 was E-51, the type of the o-cresol novolac epoxy resin in example 6 was CYDCN-200, the type of the bisphenol A epoxy resin in example 7 was CYD-128, and the type of the phenol novolac epoxy resin in example 8 was F-51.

TABLE 1 examples 4-8 formulation ingredients (unit: parts by mass)

Note: the "\\" in the table indicates that the material composition of this example does not contain the material corresponding to the row in which it is located.

Comparative example 1

Prepared according to the preparation method disclosed in CN103113841A, 20 g of epoxy resin HyPox DA323, 30 g of four-functional group epoxy resin (TGDDM), 5g of liquid nitrile rubber, 6 g of silicon dioxide powder, 1 g of carbon black and 0.3 g of asbestos powder are uniformly stirred and mixed to form a component A; 10 g of polythiol EH-316, 5g of 2, 2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane (BAHPFP), 1 g of DMP-30, 5g of KH-550 silane coupling agent (gamma-chloropropyltriethoxysilane), 5g of silicon dioxide powder and 1 g of titanium dioxide are uniformly stirred and mixed to form a component B, and A, B components are uniformly mixed according to the ratio of 1: 1 to prepare the plugging agent.

Comparative example 2

The preparation method is disclosed in CN106367047A, and comprises the steps of stirring 20 g of phenol furfural resin, 20 g of polyurethane modified epoxy resin and 20 g of Novolac vinyl ester resin at 80 ℃ for 1h, adding 5g of oxidized polyethylene wax, continuing stirring for 0.5h, cooling to 30 ℃, adding 35mL of acetone, continuing stirring for 0.5h, and obtaining a component A; kneading 15g of hydroxy diethyl triamine, 15g of methyl methacrylate, 20 g of oxidized polyethylene wax and 40 g of talcum powder at the temperature of 30 ℃ and stirring for 0.5h to obtain a component B; the component A and the component B are as follows: mixing and stirring the mixture with the ratio of ethyl to 4:1 to obtain the plugging paste.

Examples of the experiments

The properties of the plugging agents prepared in 8 examples were compared with those of 2 comparative examples, and the results are shown in Table 2. Wherein, the density test adopts the standard of GB/T4472 plus 2011 determination of density and relative density of chemical products, the curing time test adopts the standard of GB/T14074.7-1993 determination of curing time of wood adhesive and resin test method thereof, the compressive strength test adopts the standard of GB/T2567 plus 2008 resin casting body performance test method, and the gas channeling resistance test adopts the part 5 of the SY/T5504.5-2010 oil well cement admixture evaluation method: according to the Standard of the gas channeling prevention agent, the pH value test adopts the Standard of GB/T9724-2007 chemical reagent pH value determination general rules.

TABLE 2 comparison table of plugging agent performance

The results show that the annular plugging agent for the oil casing of the high-sulfur-content gas well can be maintained for more than 3 hours at the curing time of 90-130 ℃, and has the advantages of compressive strength, gas channeling resistance and H resistance₂The S concentration and the pH value performance of the alkali-resistant liquid are also obviously superior to those of the existing plugging agent, and the density is also improved compared with that of the existing plugging agent system, so that the plugging agent is excellent in comprehensive performance and suitable for the oil casing annulus plugging agent of the high-sulfur-content gas well.