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CN-121991652-A - Multi-scene self-adaptive gradient composite drilling fluid slurry and preparation method thereof

CN121991652ACN 121991652 ACN121991652 ACN 121991652ACN-121991652-A

Abstract

The invention discloses multi-scene self-adaptive gradient composite drilling fluid slurry and a preparation method thereof, wherein the multi-scene self-adaptive gradient composite drilling fluid slurry comprises, by weight, 20-30% of modified sepiolite, 12-25% of sodium red clay, 8-15% of nano filler-red clay compound, 4-8% of pH response type filtrate reducer, 3-6% of environment-friendly lubricant, 0.5-2% of bio-based antibacterial agent and the balance of deionized water, the modified sepiolite is modified by grafting acrylic acid with silane coupling agent, the nano filler-red clay compound is a compound loaded on the surface of red clay by nano calcium carbonate, the pH response type filtrate reducer is a compound of polyaspartic acid and chitosan quaternary ammonium salt or a compound of polyepoxysuccinic acid and chitosan quaternary ammonium salt, the environment-friendly lubricant is modified vegetable oil microemulsion, and the density of the multi-scene self-adaptive gradient composite drilling fluid slurry is 1.3-1.7 g/cm 3 . The invention solves the problems of insufficient salt resistance and environmental protection of the existing drilling fluid.

Inventors

  • LI ZHENDONG
  • WANG MINGYANG
  • YANG SHENQIANG
  • ZHANG BIN
  • LIU MING
  • LI ZHONGFENG
  • JIN SHUAI
  • XU JIANFENG
  • YU YINGJIE
  • SUN XIANFENG

Assignees

  • 中国建筑第八工程局有限公司

Dates

Publication Date
20260508
Application Date
20251229

Claims (8)

  1. 1. The multi-scene self-adaptive gradient composite drilling fluid slurry is characterized by comprising, by weight, 20-30% of modified sepiolite, 12-25% of sodium red clay, 8-15% of nano filler-red clay compound, 4-8% of pH response type filtrate reducer, 3-6% of environment-friendly lubricant, 0.5-2% of bio-based antibacterial agent and the balance of deionized water; The modified sepiolite adopts silane coupling agent grafted acrylic acid to modify the sepiolite; The nano filler-red clay compound is a compound with nano calcium carbonate loaded on the surface of red clay; the pH responsive filtrate reducer is a compound of polyaspartic acid and chitosan quaternary ammonium salt or a compound of polyepoxysuccinic acid and chitosan quaternary ammonium salt; The environment-friendly lubricant is modified vegetable oil microemulsion; The density of the multi-scene self-adaptive gradient composite drilling fluid slurry is 1.3-1.7 g/cm 3 .
  2. 2. The multi-scenario adaptive gradient composite drilling fluid mud of claim 1, wherein the modified vegetable oil microemulsion is a modified rapeseed oil microemulsion, a modified coconut oil microemulsion, or a modified soybean oil microemulsion.
  3. 3. The multi-scenario adaptive gradient composite drilling fluid mud of claim 2, wherein the bio-based antimicrobial agent is a tea tree oil extract, rosemary extract, or bacillus extracellular polysaccharide.
  4. 4. The multi-scenario adaptive gradient composite drilling fluid mud of claim 3, comprising 240 parts by mass of modified sepiolite, 140 parts by mass of sodium red clay, 90 parts by mass of nanofiller-red clay composite, 70 parts by mass of polyaspartic acid and chitosan quaternary ammonium salt composite, 50 parts by mass of modified rapeseed oil microemulsion, 10 parts by mass of tea tree oil extract, and 390 parts by mass of deionized water.
  5. 5. The multi-scenario adaptive gradient composite drilling fluid mud of claim 3, comprising 260 parts by mass of modified sepiolite, 130 parts by mass of sodium red clay, 110 parts by mass of nanofiller-red clay composite, 50 parts by mass of polyaspartic acid and chitosan quaternary ammonium salt composite, 60 parts by mass of modified rapeseed oil microemulsion, 5 parts by mass of tea tree oil extract, and 385 parts by mass of deionized water.
  6. 6. The multi-scenario adaptive gradient composite drilling fluid mud of claim 3, comprising 280 parts by mass of modified sepiolite, 180 parts by mass of sodium red clay, 150 parts by mass of nanofiller-red clay composite, 80 parts by mass of polyaspartic acid and chitosan quaternary ammonium salt composite, 40 parts by mass of modified rapeseed oil microemulsion, 8 parts by mass of tea tree oil extract, and 342 parts by mass of deionized water.
  7. 7. The multi-scenario adaptive gradient composite drilling fluid mud of claim 3, comprising 220 parts by mass of modified sepiolite, 200 parts by mass of sodium red clay, 130 parts by mass of nanofiller-red clay composite, 30 parts by mass of polyepoxysuccinic acid and chitosan quaternary ammonium salt composite, 50 parts by mass of modified coconut oil microemulsion, 5 parts by mass of rosemary extract, and 365 parts by mass of deionized water.
  8. 8. A method for preparing the multi-scene adaptive gradient composite drilling fluid slurry according to any one of claims 1 to 7, comprising the following steps: mixing and uniformly stirring the modified sepiolite and the sodium red clay to obtain a first dry material; Adding the nano filler-red clay compound into the first dry material, and uniformly mixing and stirring to obtain a second dry material; adding a pH response type filtrate reducer into the second dry material, and uniformly stirring to obtain a first wet material; adding an environment-friendly lubricant into the first wet material and uniformly stirring to obtain a second wet material; and adding the bio-based antibacterial agent and deionized water into the second wet material, and uniformly stirring to prepare the multi-scene self-adaptive gradient composite drilling fluid slurry.

Description

Multi-scene self-adaptive gradient composite drilling fluid slurry and preparation method thereof Technical Field The invention relates to the technical field of drilling fluid, in particular to multi-scene self-adaptive gradient composite drilling fluid slurry and a preparation method thereof. Background Drilling fluid is a generic term for various circulating fluids that meet the needs of drilling operations during the drilling process in its various functions. The drilling fluid can be divided into clear water, slurry, clay-free phase flushing fluid, emulsion, foam, compressed air and the like according to the components. Clear water is the earliest drilling fluid used, does not need to be treated, is convenient to use, and is suitable for the areas with complete rock stratum and sufficient water sources. The mud is a widely used drilling fluid, and is mainly suitable for rock formations with unstable hole wall, such as loose, crack development, easy collapse and block falling, water swelling and peeling, and the like. The existing drilling fluid has the problems of insufficient salt resistance, poor high-temperature stability, single wall protection, environmental protection defect and the like. Specifically, the traditional bentonite is easy to generate ion exchange failure in a high-salt stratum, so that the viscosity is suddenly reduced, the salt resistance is insufficient, the sepiolite-based drilling fluid is easy to dehydrate and harden at a temperature above 180 ℃, loses rheological property and has poor high-temperature stability, the shale hydration is inhibited by relying on a chemical inhibitor (such as KCl), the blocking effect on a complex fracture stratum is limited, the wall protection is single, the stratum is polluted by an oil-based or heavy metal additive (such as sulfonated lignite), and the environment-friendly exploration requirement is not met. Disclosure of Invention In order to overcome the defects existing in the prior art, the multi-scene self-adaptive gradient composite drilling fluid slurry and the preparation method thereof are provided, so that the problems of insufficient salt resistance and environmental protection of the existing drilling fluid are solved. In order to achieve the above purpose, the multi-scene self-adaptive gradient composite drilling fluid slurry is provided, and comprises, by weight, 20-30% of modified sepiolite, 12-25% of sodium red clay, 8-15% of nano filler-red clay compound, 4-8% of pH responsive filtrate reducer, 3-6% of environment-friendly lubricant, 0.5-2% of bio-based antibacterial agent and the balance deionized water; The modified sepiolite adopts silane coupling agent grafted acrylic acid to modify the sepiolite; The nano filler-red clay compound is a compound with nano calcium carbonate loaded on the surface of red clay; the pH responsive filtrate reducer is a compound of polyaspartic acid and chitosan quaternary ammonium salt or a compound of polyepoxysuccinic acid and chitosan quaternary ammonium salt; The environment-friendly lubricant is modified vegetable oil microemulsion; The density of the multi-scene self-adaptive gradient composite drilling fluid slurry is 1.3-1.7 g/cm 3. Further, the modified vegetable oil microemulsion is modified rapeseed oil microemulsion, modified coconut oil microemulsion or modified soybean oil microemulsion. Further, the bio-based antibacterial agent is a tea tree oil extract, a rosemary extract or bacillus extracellular polysaccharide. Further, the modified sepiolite/red clay composite comprises 240 parts by mass of modified sepiolite, 140 parts by mass of sodium red clay, 90 parts by mass of nano filler-red clay composite, 70 parts by mass of composite of polyaspartic acid and chitosan quaternary ammonium salt, 50 parts by mass of modified rapeseed oil microemulsion, 10 parts by mass of tea tree oil extract and 390 parts by mass of deionized water. Further, the modified sepiolite composite comprises 260 parts by mass of modified sepiolite, 130 parts by mass of sodium red clay, 110 parts by mass of nano filler-red clay composite, 50 parts by mass of composite of polyaspartic acid and chitosan quaternary ammonium salt, 60 parts by mass of modified rapeseed oil microemulsion, 5 parts by mass of tea tree oil extract and 385 parts by mass of deionized water. Further, the modified sepiolite/red clay composite comprises 280 parts by mass of modified sepiolite, 180 parts by mass of sodium red clay, 150 parts by mass of nano filler-red clay composite, 80 parts by mass of composite of polyaspartic acid and chitosan quaternary ammonium salt, 40 parts by mass of modified rapeseed oil microemulsion, 8 parts by mass of tea tree oil extract and 342 parts by mass of deionized water. Further, the modified sepiolite/red clay composite comprises 220 parts by mass of modified sepiolite, 200 parts by mass of sodium red clay, 130 parts by mass of nano filler-red clay composite, 30 parts by mass of composite of polyepoxysucc