CN-121991662-A - Oil-soluble temporary plugging agent for protecting broad-spectrum drilling oil-gas reservoir and preparation method thereof

Abstract

The invention discloses an oil-soluble temporary plugging agent for protecting a broad-spectrum drilling oil and gas reservoir and a preparation method thereof, which belong to the technical field of temporary plugging agents and comprise, by weight, 1.2-6.8 parts of a flexible resin material, 1.9-7.5 parts of a rigid resin material, 0.3-0.7 part of a particle size regulator, 0.2-0.6 part of a particle nucleating agent and 0.1-0.3 part of an interface modifier. The melting point is adjustable within the range of 60-120 ℃, the particle size is controllable within the range of 0.01-2.0 mm, and the self flexible structural characteristics of the oil-gas temporary plugging agent are adopted, so that the oil-gas temporary plugging agent has broad universality, can be perfectly matched with pore structures of different oil-gas reservoirs, and effectively solves the problems of concentrated distribution of softening points, mismatching of the particle size and the pore structures of the reservoirs and the like of the traditional oil-soluble temporary plugging agent.

Inventors

• ZHANG XIAOPING
• DING LEI
• WANG JINGGUANG
• QU BO
• XU CHAOYANG
• GUO KANG
• CHEN LEI
• CAO HUI
• JIA JUN
• Lu Lvsheng

Assignees

• 中国石油天然气集团有限公司
• 中国石油集团川庆钻探工程有限公司

Dates

Publication Date

20260508

Application Date

20241104

Claims (10)

1. 1. The broad-spectrum oil-gas reservoir protection oil-soluble temporary plugging agent is characterized by comprising the following components in parts by weight: 1.2-6.8 parts of flexible resin material; 1.9 to 7.5 parts of rigid resin material; 0.3-0.7 parts of particle size regulator; 0.2-0.6 parts of particle nucleating agent; 0.1 to 0.3 parts of interface modifier.
2. 2. The broad-spectrum oil and gas reservoir protection oil-soluble temporary plugging agent according to claim 1, wherein the flexible resin material is one or two selected from normal paraffin, polyethylene wax and full-refined paraffin.
3. 3. The oil-soluble temporary plugging agent for protecting a broad-spectrum well drilling oil and gas reservoir according to claim 1, wherein the rigid resin material is one or two selected from carbon five petroleum resin, carbon nine petroleum resin and coumarone resin.
4. 4. The oil-soluble temporary plugging agent for protecting a broad-spectrum well drilling oil and gas reservoir according to claim 1, wherein the particle size regulator is one or two selected from sodium dodecyl benzene sulfonate, tween 61 and copolymer SCRIPSET SMA of styrene maleic anhydride.
5. 5. The broad-spectrum oil and gas reservoir protection oil-soluble temporary plugging agent according to claim 1, wherein the particle nucleating agent is one or two selected from ultrafine calcium carbonate particles, silicon nitride nanoparticles and Fe3O4 coupled polyaniline nanoparticles.
6. 6. The broad-spectrum oil and gas reservoir protection oil-soluble temporary plugging agent according to claim 1, wherein the interface modifier is one or two selected from nano graphene oxide, nano silicon dioxide and molybdenum oxide nano particles.
7. 7. The preparation method of the oil-soluble temporary plugging agent for protecting the broad-spectrum drilling oil and gas reservoir is characterized by comprising the following steps of: Firstly, weighing 1.2 to 6.8 parts of flexible resin material, 1.0 to 7.5 parts of rigid resin material, 0.3 to 0.7 part of particle size regulator, 0.2 to 0.6 part of particle nucleating agent and 0.1 to 0.3 part of interface modifier according to mass composition; heating the flexible resin material and the rigid resin material to enable the flexible resin material and the rigid resin material to be completely melted, and obtaining mixed resin through mechanical stirring for later use; step three, adding the particle size regulator into 15.6-17.4 parts of n-heptane, and uniformly dispersing the mixture under constant-speed stirring to obtain a particle size regulator dispersion liquid for later use; step four, adding the mixed resin into an n-heptane system containing a particle size regulator, heating under constant-speed stirring, and preparing a resin dispersion liquid for later use after the mixed resin is completely dissolved; Step five, adding the particle nucleating agent and the interface modifier into 135-145 parts of laboratory water, and heating under constant-speed stirring to obtain a particle nucleating agent and interface modifier mixed dispersion liquid for later use; And step six, slowly adding the resin dispersion liquid into the mixed dispersion liquid of the particle nucleating agent and the interface modifier under constant-speed shearing, then shearing the reaction system to room temperature at constant speed, collecting particles suspended in a water body, and washing with water to obtain the oil-soluble temporary plugging agent for protecting the broad-spectrum drilling oil and gas reservoir.
8. 8. The preparation method of the broad-spectrum oil and gas reservoir protection oil-soluble temporary plugging agent is characterized by comprising the steps of heating to 120-140 ℃ in the second step and the fourth step, and heating to 80-90 ℃ in the fifth step.
9. 9. The preparation method of the broad-spectrum oil and gas reservoir protection oil-soluble temporary plugging agent for drilling is characterized in that the constant-speed stirring rotation speed in the third step, the fourth step and the fifth step is 200 r/min-300 r/min, and the constant-speed shearing rotation speed in the sixth step is 7000 r/min-9000 r/min.
10. 10. The preparation method of the broad-spectrum oil and gas reservoir protection oil-soluble temporary plugging agent is characterized in that the resin dispersion liquid is slowly added into the mixed dispersion liquid of the particle nucleating agent and the interface modifier under constant-speed shearing, and the addition time is controlled to be 3 min-5 min.

Description

Oil-soluble temporary plugging agent for protecting broad-spectrum drilling oil-gas reservoir and preparation method thereof Technical Field The invention relates to the technical field of temporary plugging agents, in particular to an oil-soluble temporary plugging agent for protecting a broad-spectrum drilling oil-gas reservoir and a preparation method thereof. Background In the oil and gas exploration and development process, various links from drilling and opening the oil and gas layer to well completion, well cementation, perforation, acidification, fracturing, well repair, well flushing and the like inevitably cause damage or pollution to the oil and gas reservoir to a certain extent. The damage of well-entering fluid to the oil and gas reservoir is mainly reflected by invasion of external solid particles and liquid invasion, which causes hydration and expansion of stratum clay, migration of particles, chemical precipitation and the like, so that an oil and gas channel is blocked, the peripheral permeability of a well hole of a production well is reduced, and the productivity of an oil layer is reduced. Reservoir damage in the drilling process directly causes deviation of well test and well logging data interpretation of a development layer, causes huge economic loss to an oil field, and also increases the cost of later-stage oil testing, acidification, fracturing, blocking removal, well repair and other operations. Therefore, reducing damage to the reservoir by drilling fluids is one of the issues that have been seriously addressed in recent years during drilling and completion operations, the quality of which is directly related to the overall economic benefits of oil and gas exploration and development. At present, ultrafine calcium carbonate is mostly used as temporary plugging agents for protecting oil well reservoirs, and the problems that the invasion depth is large, the plugging is irreversible, the later acidification plugging removal is needed, the plugging removal working procedure is increased, the drilling working period is prolonged, and the acid-sensitive stratum is not suitable exist. In addition, the granularity of various plugging agents is poor in matching with the gap width of a reservoir stratum, and is presumed by adopting adjacent well data, so that the granularity of the plugging agents is not adjustable, and the reservoir stratum protection effect is limited. The oil-soluble temporary plugging technology is mainly used for reservoir protection measures in the drilling process in recent years, and chemical agents with temporary plugging effects are utilized to protect an oil-gas reservoir and reduce drilling fluid damage. The oil-soluble temporary plugging agent utilizes a chemical agent with a temporary plugging effect, and has the advantages of being capable of realizing selective temporary plugging, effectively reducing the damage depth of an oil-gas reservoir, timely responding to automatic dissolution and plugging removal of oil-gas, reducing damage of drilling fluid, enhancing the protection effect of an oil layer and the like. However, the conventional oil-soluble temporary plugging agent has a relatively concentrated softening point, the softening point is a single temperature point, such as 60, 80, 100 ℃ and the like, a series of temperatures are not formed, meanwhile, the oil-soluble temporary plugging agent has a relatively low oil solubility, the oil solubility is mainly concentrated at 75-85%, in addition, the relatively low oil solubility also causes the recovery rate of the core permeability to be relatively low, the recovery rate is about 50%, the granularity of the oil-soluble temporary plugging agent is relatively poor in matching with the gap width of an oil-gas reservoir, and the reservoir protection effect is severely limited. In view of the above, aiming at the problems of concentrated softening point, low oil solubility, unmatched particle size and reservoir, low core permeability recovery rate and the like of the conventional oil-soluble temporary plugging agent, there is a need to develop an oil-soluble temporary plugging agent for protecting a broad-spectrum drilling oil-gas reservoir, which has adjustable particle size and softening point according to different reservoir conditions and excellent plugging strength and plugging removal performance, so as to reduce damage of drilling fluid to the oil-gas reservoir. Disclosure of Invention The invention aims to solve the problems of concentrated softening point, low oil solubility, unmatched particle size and reservoir, low core permeability recovery rate and the like of the oil-soluble temporary plugging agent in the prior art, and provides the oil-soluble temporary plugging agent for protecting the oil-gas reservoir in a broad-spectrum drilling and a preparation method thereof, wherein the melting point is adjustable within the range of 60-120 ℃, and the particle size is controllable within the range of