Search

CN-121991282-A - Fluid loss additive, oil-based drilling fluid and preparation method and application thereof

CN121991282ACN 121991282 ACN121991282 ACN 121991282ACN-121991282-A

Abstract

The invention provides a filtrate reducer, oil-based drilling fluid and a preparation method and application thereof. The preparation method of the filtrate reducer comprises the steps of mixing acrylonitrile, isobutene and acetone, heating and stirring to perform a first reaction, dropwise adding fuming sulfuric acid in the heating and stirring process to obtain a first mixture, mixing N-alkylacrylamide and the first mixture, heating to perform a second reaction to obtain a second mixture, mixing dimethylaminoethyl methacrylate and the second mixture, heating to perform a third reaction to obtain a third mixture, mixing ethylbenzene, carbon tetrachloride and the third mixture, heating to perform a fourth reaction to obtain a fourth mixture, and extracting and washing the fourth mixture with absolute ethyl alcohol to obtain white floccules, namely the filtrate reducer. The oil-based drilling fluid comprises an oil phase, bentonite, the filtrate reducer, the flow pattern regulator, the weighting agent and sodium hydroxide. The oil-based drilling fluid provided by the invention has good high-temperature filtrate loss reduction performance and is suitable for deep well ultra-deep well drilling.

Inventors

  • FAN YU
  • CHEN YE
  • WU PENGCHENG
  • WANG XUDONG
  • WAN XIUMEI
  • WANG ZHIQIANG

Assignees

  • 中国石油天然气股份有限公司

Dates

Publication Date
20260508
Application Date
20241108

Claims (14)

  1. 1. A method for preparing a filtrate reducer, wherein the method comprises the following steps: Mixing acrylonitrile, isobutene and acetone, heating and stirring to perform a first reaction, and dropwise adding fuming sulfuric acid in the heating and stirring process to obtain a first mixture; mixing N-alkyl acrylamide with the first mixture, and heating to perform a second reaction to obtain a second mixture; Mixing dimethylaminoethyl methacrylate with the second mixture, and heating for a third reaction to obtain a third mixture; mixing ethylbenzene, carbon tetrachloride and the third mixture, heating to perform a fourth reaction to obtain a fourth mixture And (3) extracting and washing the fourth mixture by using absolute ethyl alcohol to obtain white floccules, namely the filtrate reducer.
  2. 2. The method for producing a fluid loss additive according to claim 1, wherein the mass ratio of acetone to acrylonitrile to isobutylene to N-alkylacrylamide to dimethylaminoethyl methacrylate to ethylbenzene to carbon tetrachloride=100 (14-16): (10-12): (20-22): (14-16): (6-8): (6-8).
  3. 3. The method for preparing a fluid loss additive according to claim 1, wherein, The temperature of the first reaction is 30-35℃, and/or The time of the first reaction is 10-15min.
  4. 4. The method for preparing a fluid loss additive according to claim 1, wherein, The temperature of the second reaction is 30-35℃, and/or The second reaction time is 10-15min.
  5. 5. The method for preparing a fluid loss additive according to claim 1, wherein, The temperature of the third reaction is 50-54℃, and/or The third reaction time is 20-26min.
  6. 6. The method for preparing a fluid loss additive according to claim 1, wherein, The temperature of the fourth reaction is 66-68℃, and/or The fourth reaction time is 34-36min.
  7. 7. A fluid loss additive obtainable by the process of any one of claims 1 to 6.
  8. 8. Use of the fluid loss additive of claim 7 in oil-based drilling fluids.
  9. 9. An oil-based drilling fluid, wherein the oil-based drilling fluid comprises an oil phase, bentonite, the fluid loss additive of claim 7, a flow pattern regulator, a weighting agent and sodium hydroxide; based on 100 parts by weight of oil phase, 3-6 parts by weight of bentonite, 4-8 parts by weight of filtrate reducer, 4-8 parts by weight of flow pattern regulator, 70-80 parts by weight of weighting agent and 1-3 parts by weight of sodium hydroxide.
  10. 10. The oil-based drilling fluid of claim 9, wherein the oil phase is selected from white oil.
  11. 11. The oil-based drilling fluid of claim 9, wherein the flow modifier is xanthan gum.
  12. 12. The oil-based drilling fluid of claim 9, wherein the weighting agent is selected from barite.
  13. 13. The method of preparing an oil-based drilling fluid of any one of claims 9-12, wherein the method comprises: And uniformly mixing the oil phase, bentonite, the filtrate reducer, the flow pattern regulator, the weighting agent and sodium hydroxide provided by the second aspect of the invention to obtain the oil-based drilling fluid.
  14. 14. Use of the oil-based drilling fluid of any one of claims 9-12 in wellbore unstable formations drilling construction.

Description

Fluid loss additive, oil-based drilling fluid and preparation method and application thereof Technical Field The invention belongs to the technical field of drilling fluid, and particularly relates to a filtrate reducer, an oil-based drilling fluid and a preparation method and application thereof. Background With the rapid development of economy, the demand for natural gas is rapidly increased, the contradiction between supply and demand is increasingly outstanding, the development of petroleum and natural gas is expanded to deep wells and ultra-deep wells, but compared with traditional shallow wells, the deep wells and ultra-deep wells have the advantages of increased concealment and complexity of geological environment, stronger uncertainty of mechanical properties and higher challenge on well wall stability, and are technical problems which plague drilling engineering for a long time. 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 drilling fluid has the defects of low high-temperature filtration performance, and the drilling fluid has the defects of large filtration loss and incapability of forming effective plugging when plugging the cracks of the deep well and ultra-deep well stratum, so that a large amount of drilling fluid enters the stratum, and the unstable well wall collapses. Therefore, the technical scheme of the drilling fluid with good high-temperature reduction filtration performance suitable for deep well and ultra-deep well drilling needs to be researched at present. Disclosure of Invention The invention aims to provide a drilling fluid technical scheme which has good high-temperature reduction filtration performance and is suitable for deep well and ultra-deep well drilling. In order to achieve the above purpose, the present invention provides the following technical solutions. In a first aspect, the invention provides a method for preparing a fluid loss additive, wherein the method comprises the following steps: Mixing acrylonitrile, isobutene and acetone, heating and stirring to perform a first reaction, and dropwise adding fuming sulfuric acid in the heating and stirring process to obtain a first mixture; mixing N-alkyl acrylamide with the first mixture, and heating to perform a second reaction to obtain a second mixture; Mixing dimethylaminoethyl methacrylate with the second mixture, and heating for a third reaction to obtain a third mixture; mixing ethylbenzene, carbon tetrachloride and the third mixture, heating to perform a fourth reaction to obtain a fourth mixture And (3) extracting and washing the fourth mixture by using absolute ethyl alcohol to obtain white floccules, namely the filtrate reducer. According to a preferred embodiment of the first aspect, preferably, the acetone/acrylonitrile/isobutylene/N-alkylacrylamide/dimethylaminoethyl methacrylate/ethylbenzene/carbon tetrachloride=100 (14-16): (10-12): (20-22): (14-16): (6-8): (6-8) in mass ratio. According to a preferred embodiment of the first aspect, the temperature of the first reaction is preferably between 30 and 35 ℃. According to a preferred embodiment of the first aspect, the time of the first reaction is preferably from 10 to 15 minutes. According to a preferred embodiment of the first aspect, the temperature of the second reaction is preferably between 30 and 35 ℃. According to a preferred embodiment of the first aspect, the time of the second reaction is preferably 10-15min. According to a preferred embodiment of the first aspect, the temperature of the third reaction is preferably 50-54 ℃. According to a preferred embodiment of the first aspect, the time for the third reaction is preferably 20-26min. According to a pref