合成锂皂石用作超高温水基钻井液增黏剂实验研究

针对现有聚合物增黏剂抗温能力不足的问题，无法满足超高温（耐240℃）水基钻井液使用要求，提出采用合成锂皂石作为水基钻井液超高温增黏剂。采用X射线粉晶衍射及热重分析对合成锂皂石进行了结构表征，对其増黏性能、抗温性及抗盐性能等进行了评价，并分析了合成锂皂石抗高温增黏机理。实验结果发现:合成锂皂石H-6具有优良的増黏性能和热稳定性，抗温能力可达240℃，而且抗高温増黏效果优于现有国内外高温增黏剂产品。在4%钠膨润土基浆中加入1% H-6，240℃高温老化16 h前后浆液的表观黏度均为16.5 mPa·s，而加有1%高温增黏剂HE300的钠土基浆经240℃老化16 h后其表观黏度降低率大于92%。研究结果表明，合成锂皂石与其它处理剂配伍性好，适合用作超高温增黏剂，在超高温水基钻井液中具有广阔的应用前景。 

Mechanisms of Synthetic Hectorite to Viscosify Ultra-high Temperature Water Base Muds

Polymers are generally used for viscosifying water base drilling fluids, but their tolerance to high temperature is not suffcient to meet the requirements of ultra-high temperature water base drilling fluids. It is thus proposed that artifcial hectorite can be used as an ultra-high temperature viscosifer for water base drilling fluids. Characterization of the structure of the synthesized hectorite with X-ray powder diffraction and TGA showed that the synthesized hectorite, H-6, has excellent viscosifying property and thermal stability; it is able to function normally at temperature of up to 240℃, and its viscosifying effect at high temperature is superior to other high temperature viscosifers presently used worldwide. Testing of a 4% sodium-bentonite water base mud treated with 1% H-6 showed that after aging at 240℃ for 16 hours, the water base mud had the same apparent viscosity of 16.5 mPa·s, before and after aging. As a comparison, another 4% sodium-bentonite water base mud treated with 1% HE300, a high temperature viscosifer, had its viscosity reduced by at least 92% after aging at 240℃ for 16 hours. Laboratory study showed that H-6 is compatible well with other commonly used additives, and is suitable for use in water base drilling fluids as an ultra-high temperature viscosifer. It will fnd wide application in formulating ultra-high temperature water base drilling fluids.