CN-122011279-A - High-temperature-resistant suspending agent for water-based drilling fluid, and preparation method and application thereof

CN122011279ACN 122011279 ACN122011279 ACN 122011279ACN-122011279-A

Abstract

The invention relates to the technical field of additive treatment of drilling fluid, and discloses a high-temperature-resistant suspending agent for water-based drilling fluid, a preparation method and application thereof. The high-temperature-resistant suspending agent for the water-based drilling fluid is a polymer, and comprises a repeating unit A derived from unsaturated sulfonate and a repeating unit B derived from unsaturated lactam, wherein the unsaturated sulfonate comprises unsaturated sulfonate a and unsaturated sulfonate B, the unsaturated sulfonate a is benzene-free unsaturated sulfonate, and the unsaturated sulfonate B is benzene-containing unsaturated sulfonate. The invention adopts the high temperature resistant suspending agent polymer formed by the thermal initiation polymerization of the unsaturated sulfonate and the unsaturated lactam, improves the suspending ability of the drilling fluid to the weighting material by utilizing the dispersibility and good thixotropic property of the sulfonate, and improves the temperature resistant performance of the polymer by the unsaturated lactam, thereby effectively solving the problem that the weighting material may be seriously settled under the high temperature condition of the drilling fluid.

Inventors

LIN XIN
LI GONGRANG
LI YECHENG
ZHAO HUAIZHEN
WANG CHENGJUN
LIU ZHENDONG

Assignees

中石化石油工程技术服务股份有限公司
中石化胜利石油工程有限公司
中石化胜利石油工程有限公司钻井液技术服务中心
山东胜工石油科技有限公司

Dates

Publication Date: 20260512
Application Date: 20241112

Claims (10)

1. The high-temperature-resistant suspending agent for the water-based drilling fluid is characterized in that the suspending agent is a polymer and comprises a repeating unit A derived from unsaturated sulfonate and a repeating unit B derived from unsaturated lactam; The unsaturated sulfonate comprises unsaturated sulfonate a and unsaturated sulfonate b, wherein the unsaturated sulfonate a is unsaturated sulfonate without benzene, and the unsaturated sulfonate b is unsaturated sulfonate with benzene.
2. The high temperature resistant suspension agent for water-based drilling fluid according to claim 1, wherein the unsaturated sulfonate b is at least one selected from the group consisting of p-styrene sulfonate, vinyl phenyl sulfonate and allyl benzene sulfonate; and/or the unsaturated sulfonate a is selected from at least one of 2-acrylamido-2-methylpropanesulfonate, vinyl sulfonate, allyl sulfonate, 2-acryloyloxy-2-methylpropanesulfonate and 2, 3-epoxypropane sulfonate.
3. The high temperature resistant suspension agent for water-based drilling fluid according to claim 2, wherein the unsaturated sulfonate a is selected from at least two of sodium 2-acrylamido-2-methylpropanesulfonate, sodium vinylsulfonate, sodium 2-allylsulfonate, sodium 2-acryloyloxy-2-methylpropanesulfonate and sodium 2, 3-epoxypropane sulfonate; Preferably, the unsaturated sulfonate a comprises unsaturated sulfonate a1 and unsaturated sulfonate a2, wherein the unsaturated sulfonate a1 is 2-acrylamide-2-methylpropanesulfonate sodium, and the unsaturated sulfonate a2 comprises at least one of sodium vinyl sulfonate, sodium 2-allylsulfonate, sodium 2-acryloyloxy-2-methylpropanesulfonate and sodium 2, 3-epoxypropane sulfonate.
4. A high temperature resistant suspension agent for water based drilling fluids according to any one of claims 1-3, wherein the unsaturated lactam is selected from at least one of N-vinyl pyrrolidone and N-vinyl caprolactam.
5. The high temperature resistant suspension concentrate for water-based drilling fluids according to claim 4, wherein the suspension concentrate comprises a repeating unit derived from sodium 2-acrylamido-2-methylpropanesulfonate, a repeating unit derived from unsaturated sulfonate a2, a repeating unit derived from unsaturated sulfonate b and a repeating unit derived from unsaturated lactam, and preferably the mass ratio of the repeating unit derived from sodium 2-acrylamido-2-methylpropanesulfonate, the repeating unit derived from unsaturated sulfonate a2, the repeating unit derived from unsaturated sulfonate b and the repeating unit derived from unsaturated lactam is (3-4): (7-8): (4-6): (3-5).
6. The preparation method of the high-temperature-resistant suspending agent for the water-based drilling fluid is characterized by comprising the steps of obtaining a mixed solution comprising unsaturated sulfonate, unsaturated lactam and water, and heating for polymerization reaction to obtain the high-temperature-resistant suspending agent for the water-based drilling fluid; The unsaturated sulfonate comprises unsaturated sulfonate a and unsaturated sulfonate b, wherein the unsaturated sulfonate a is unsaturated sulfonate without benzene, and the unsaturated sulfonate b is unsaturated sulfonate with benzene.
7. The preparation method of the water-based paint according to claim 6, wherein the mass ratio of the unsaturated sulfonate to the unsaturated lactam to the water is (14-18): 3-5): 40-100; and/or the pH of the mixed solution is 5-7, preferably, the pH regulator comprises at least one of sodium carbonate, potassium carbonate, calcium carbonate, sodium hydroxide, potassium hydroxide and sodium ethoxide; and/or the polymerization temperature is 180-230 ℃, preferably 200-210 ℃, and the reaction time is 16-100h, preferably 36-50h.
8. The method according to claim 6 or 7, wherein the unsaturated sulfonate b is at least one selected from the group consisting of p-styrene sulfonate, vinyl phenyl sulfonate and allyl benzene sulfonate; And/or the unsaturated sulfonate a is selected from at least one of 2-acrylamido-2-methylpropanesulfonate, vinyl sulfonate, allyl sulfonate, 2-acryloyloxy-2-methylpropanesulfonate and 2, 3-epoxypropane sulfonate, preferably at least two of sodium 2-acrylamido-2-methylpropanesulfonate, sodium vinyl sulfonate, sodium 2-allylsulfonate, sodium 2-acryloyloxy-2-methylpropanesulfonate and sodium 2, 3-epoxypropane sulfonate, preferably the unsaturated sulfonate a comprises unsaturated sulfonate a1 and unsaturated sulfonate a2, the unsaturated sulfonate a1 is sodium 2-acrylamido-2-methylpropanesulfonate, and the unsaturated sulfonate a2 comprises at least one of sodium vinyl sulfonate, sodium 2-allylsulfonate, sodium 2-acryloyloxy-2-methylpropanesulfonate and sodium 2, 3-epoxypropane sulfonate; and/or the unsaturated lactam is selected from at least one of N-vinyl pyrrolidone and N-vinyl caprolactam.
9. A high temperature resistant suspension agent for water-based drilling fluid, prepared by the preparation method of any one of claims 6-8.
10. Use of a high temperature resistant suspension agent for water-based drilling fluids according to any one of claims 1 to 5 or for water-based drilling fluids according to claim 9 in water-based drilling fluids, in particular 240 ℃ water-based drilling fluids.

Description

High-temperature-resistant suspending agent for water-based drilling fluid, and preparation method and application thereof Technical Field The invention relates to the technical field of additive treatment of drilling fluid, in particular to a high-temperature-resistant suspending agent for water-based drilling fluid, a preparation method and application thereof. Background With the deep exploration and development, deep wells and ultra-deep well drilling have more strong demands for ultra-high temperature drilling fluid. In the ultra-deep well drilling process, heavy materials such as barite and the like are generally added to balance formation pressure, when a high-temperature stratum is drilled, various components in drilling fluid can undergo physical change and chemical reaction at ultra-high temperature, so that performances such as rheological property, sedimentation stability and the like of the drilling fluid are changed dramatically, particularly, the viscosity of the drilling fluid is reduced due to high-temperature degradation and the like of a polymer treatment agent in the drilling fluid, so that suspension and carrying performance of the drilling fluid are degraded, serious sedimentation and system performance degradation of the drilling fluid can occur after long-term standing, a lower pipe column is difficult to block or open a pump, and the risk of drilling and completion operation is increased. Therefore, how to ensure that the weighting materials are well dispersed and suspended in the drilling fluid in a high-temperature environment and maintain the suspension stability of the drilling fluid is one of the key technologies facing ultra-deep well ultra-high temperature drilling fluid. Disclosure of Invention The invention provides a high-temperature-resistant suspending agent for water-based drilling fluid, a preparation method and application thereof, and aims to solve the technical problem that heavy materials can be seriously settled under the high-temperature condition of the prior art drilling fluid. The invention adopts the high temperature resistant suspending agent polymer formed by the thermal initiation polymerization of the unsaturated sulfonate and the unsaturated lactam, improves the suspending ability of the drilling fluid to the weighting material by utilizing the dispersibility and good thixotropic property of the sulfonate, and improves the temperature resistant performance of the polymer by the unsaturated lactam, thereby effectively solving the problem that the weighting material may be seriously settled under the high temperature condition of the drilling fluid. The invention aims at providing a high-temperature resistant suspending agent for water-based drilling fluid, which is a polymer and comprises a repeating unit A derived from unsaturated sulfonate and a repeating unit B derived from unsaturated lactam; The unsaturated sulfonate comprises unsaturated sulfonate a and unsaturated sulfonate b, wherein the unsaturated sulfonate a is unsaturated sulfonate without benzene, and the unsaturated sulfonate b is unsaturated sulfonate with benzene. The unsaturated sulfonate and the unsaturated lactam of the invention are polymerized to form a polymer by thermal initiation, the unsaturated sulfonate forms a repeating unit A, and the unsaturated lactam forms a repeating unit B. The suspending agent provided by the invention can effectively strengthen the space reticular structure of drilling fluid, improve the bearing capacity of the drilling fluid to the barite, improve the dynamic stability of the drilling fluid after weighting, and improve the dispersibility and suspension stability of weighting materials such as the barite and the like in the drilling fluid under the high temperature condition. The invention selects the unsaturated lactam, the unsaturated lactam has great steric hindrance, and can further reduce the molecular weight of the polymer, thereby improving the temperature resistance of the polymer, and the cyclic structure of the lactam can reduce the damage of shearing force in a high-temperature environment to the polymer, and improve the structural stability of the polymer. The benzene ring in the unsaturated benzene sulfonate can improve the rigidity and the temperature resistance of the polymer molecule. The drilling fluid system is not a single treating agent, each treating agent has different functions, and the suspending agent is used for lifting and cutting, namely, lifting the dynamic cutting force YP, the initial cutting force G 'and the final cutting force G'. The suspending agent has different functions with the filtrate reducer and the tackifier. Fluid loss additives are used to increase the fluid loss resistance of the slurry, i.e., API fluid loss and HTHP fluid loss. The tackifier is used for improving apparent viscosity AV and plastic viscosity PV of the drilling fluid. Several treatment tests involve test methods that are very different. Accord