CN-121992654-A - Modified silica fiber and oil-based drilling fluid and preparation method thereof

CN121992654ACN 121992654 ACN121992654 ACN 121992654ACN-121992654-A

Abstract

The invention provides a modified silica fiber, an oil-based drilling fluid and a preparation method thereof. The preparation method of the modified silica fiber comprises the steps of carrying out surface modification on the silica fiber by using a silane coupling agent to obtain a first modified product, and carrying out surface modification on the first modified product by using lauroyl glutamic acid and tert-butyl peroxypivalate to obtain the modified silica fiber. The oil-based drilling fluid comprises, by weight, 3-8 parts of bentonite, 7-10 parts of a flow-type regulator, 3-5 parts of a fluid loss additive, 18-22 parts of modified silica fibers, 8-12 parts of a lubricant and 20-26 parts of a weighting agent, wherein 100 parts of the oil phase is taken as a reference, and the fluid loss additive is used for reducing the weight of the oil phase. The oil-based drilling fluid provided by the invention has good solid-phase dispersion performance and plugging performance.

Inventors

WU PENGCHENG
FAN YU
CHEN YE
WANG XUDONG
HUANG MEI
WAN XIUMEI

Assignees

中国石油天然气股份有限公司

Dates

Publication Date: 20260508
Application Date: 20241108

Claims (13)

1. A method of making a modified silica fiber, wherein the method comprises: carrying out surface modification on the silicon dioxide fiber by using a silane coupling agent to obtain a first modified product; and (3) carrying out surface modification on the first modified product by using lauroyl glutamic acid and tert-butyl peroxypivalate to obtain the modified silica fiber.
2. The method for producing a modified silica fiber according to claim 1, wherein the surface modification of the silica fiber with a silane coupling agent to obtain a first modified product comprises: Dispersing silicon dioxide fibers in absolute ethyl alcohol to obtain a dispersion liquid; Mixing a silane coupling agent with water, adjusting the pH value to 3-4 by hydrochloric acid, and heating to 45-50 ℃ to obtain a silane coupling agent aqueous solution; Mixing the dispersion liquid with the aqueous solution of the silane coupling agent, and performing a first reaction at 45-50 ℃; And (3) carrying out solid-liquid separation on the product obtained by the first reaction, washing and drying the solid-phase product obtained by the solid-liquid separation to obtain a first modified product.
3. The method for producing a modified silica fiber according to claim 2, wherein the time of the first reaction is 18 to 22 minutes.
4. The method for producing a modified silica fiber according to claim 2, wherein, The mass ratio of the silicon dioxide fiber to the absolute ethyl alcohol in the dispersion liquid is 1:50-70; more preferably, the mass ratio of the silane coupling agent to water in the aqueous solution of the silane coupling agent is 1:20-30; More preferably, the mass ratio of the silica fiber to the aqueous solution of the silane coupling agent is 1:10-14.
5. The method for producing a modified silica fiber according to any one of claim 1 to 3, wherein, KH560 is selected as the silane coupling agent.
6. The method for producing a modified silica fiber according to claim 1, wherein the obtaining of the first modified product by surface modification with lauroyl glutamic acid and t-butyl peroxypivalate comprises: adding lauroyl glutamic acid and tert-butyl peroxypivalate into acetone, and heating to 55-65 ℃ to obtain a first mixture; Adding the first modified product into the first mixture, and performing a second reaction at 55-65 ℃; And (3) carrying out solid-liquid separation on a product obtained by the second reaction, and washing and drying a solid-phase product obtained by the solid-liquid separation to obtain the modified silica fiber.
7. The method for producing a modified silica fiber according to claim 6, wherein the second reaction time is 25 to 35 minutes.
8. The method for producing a modified silica fiber according to claim 6, wherein, Lauroyl glutamic acid and tert-butyl peroxypivalate with a mass ratio of 1:0.1-0.3; more preferably, the mass ratio of lauroyl glutamic acid to the first modified product is 1:4-6; More preferably, the mass ratio of lauroyl glutamic acid to acetone is 1:25-30.
9. A modified silica fiber, wherein the modified silica fiber can be produced by the production method of the modified silica fiber according to any one of claims 1 to 8.
10. Use of the modified silica fiber of claim 9 in an oil-based drilling fluid.
11. An oil-based drilling fluid, wherein the oil-based drilling fluid comprises an oil phase, bentonite, a flow pattern regulator, a fluid loss additive, the modified silica fiber of claim 9, a weighting agent, and a lubricant; based on 100 parts by weight of oil phase, 3-8 parts by weight of bentonite, 7-10 parts by weight of flow pattern regulator, 3-5 parts by weight of filtrate reducer, 18-22 parts by weight of modified silica fiber, 8-12 parts by weight of lubricant and 20-26 parts by weight of weighting agent.
12. The oil-based drilling fluid of claim 11, wherein, The oil phase is white oil; The flow-pattern regulator is xanthan gum; the weighting agent is barite; The filtrate reducer is sulfomethyl phenolic resin; The lubricant is graphite powder.
13. The method of preparing an oil-based drilling fluid of claim 11 or 12, wherein the method comprises: And uniformly mixing the oil phase, bentonite, a flow pattern regulator, a fluid loss additive, the modified silica fiber provided in the second aspect of the invention, a weighting agent and a lubricant to obtain the oil-based drilling fluid.

Description

Modified silica fiber and oil-based drilling fluid and preparation method thereof Technical Field The invention belongs to the technical field of drilling fluid, and particularly relates to modified silica fiber and oil-based drilling fluid and a preparation method thereof. Background In recent years, the exploration and development of complex oil and gas are accelerated, the drilling depth is continuously increased, the complexity of drilling into the stratum is gradually increased, and the problem of instability of the well wall of the shale stratum is gradually highlighted, so that the stability of the well wall of the drilling fluid is also endowed with higher standards and requirements. Meanwhile, with the development of high quality, improvement of environmental protection concepts and increasingly stringent environmental protection requirements of the petroleum industry, the drilling fluid technology is endowed with higher environmental protection requirements. The development of environmental-friendly drilling fluid treatment agents to form a drilling fluid system meeting the technical requirements and environmental protection indexes of drilling engineering has become one of the important directions of the current drilling fluid technical research. The instability of the well wall is one of underground complex conditions commonly encountered in drilling engineering, and the logging of geological data, the drilling speed, the drilling quality and the cost are seriously affected. And part of the new detection area can not drill a target layer due to instability of the well wall, so that exploration and development speeds are delayed, and economic benefits are affected. The essence of the instability of the well wall is mechanical instability. Instability of the borehole wall occurs when the borehole wall rock is subjected to stresses exceeding its own strength. The reason of the well instability is complex and can be mainly summarized into three aspects of mechanical factors, physical and chemical factors, engineering technical measures and the like, and the well instability of stratum such as shale, sandy or silty mud rock, fluid rock, sandstone, argillite sandstone or silty sandstone, rock magma rock and the like which are drilled in the drilling process can occur. According to the phenomenon of well wall instability encountered in practice, various technical measures for stabilizing the well wall are summarized, wherein the optimization of the type of drilling fluid and the proper treating agent is one of important measures for improving the well wall instability. However, the existing oil-based drilling fluid is generally poor in solid-phase dispersion performance, so that the plugging capability of the drilling fluid when encountering micro-cracks of a stratum is affected, the plugging capability is poor, a large amount of liquid phase enters the stratum, and the well wall collapse is caused. Therefore, the technical scheme capable of effectively solving the problem that the oil-based drilling fluid is poor in solid-phase dispersion performance and enabling the drilling fluid to have good plugging performance still needs to be studied at present. Disclosure of Invention The invention aims to provide a technical scheme capable of effectively solving the problem that oil-based drilling fluid is poor in solid-phase dispersion performance and enabling the drilling fluid to have good plugging performance. In order to achieve the above purpose, the present invention provides the following technical solutions. In a first aspect, the present invention provides a method for preparing a modified silica fiber, wherein the method comprises: carrying out surface modification on the silicon dioxide fiber by using a silane coupling agent to obtain a first modified product; and (3) carrying out surface modification on the first modified product by using lauroyl glutamic acid and tert-butyl peroxypivalate to obtain the modified silica fiber. According to a preferred embodiment of the first aspect, preferably, the surface modification of the silica fiber with a silane coupling agent to obtain a first modified product comprises: Dispersing silicon dioxide fibers in absolute ethyl alcohol to obtain a dispersion liquid; Mixing a silane coupling agent with water, adjusting the pH value to 3-4 by hydrochloric acid, and heating to 45-55 ℃ to obtain a silane coupling agent aqueous solution; mixing the dispersion liquid with the aqueous solution of the silane coupling agent, and performing a first reaction at 45-55 ℃; Carrying out solid-liquid separation on a product obtained by the first reaction, washing and drying a solid-phase product obtained by the solid-liquid separation to obtain a first modified product; more preferably, dispersing silica fibers in absolute ethanol is accomplished by: placing the silicon dioxide fibers in absolute ethyl alcohol for ultrasonic dispersion to realize that the silicon dioxide fibers