XZ-新型高性能水基钻井液的研究及应用

为了解决准噶尔盆地深井储层钻探难度大，钻井成本较高等问题，基于"封堵、抑制、固化、双疏、润滑"理论，采用仿生抑制剂XZ-YZJ、仿生封堵剂XZ-FDJ、键和润滑剂XZ-RHJ、固化成膜剂XZ-CMJ、双疏剂XZ-SSJ等处理剂，形成了适合该区块的XZ-新型高性能水基钻井液。该钻井液具有较好的流变性能，且具有较好的长时间老化性能和抗污染性能，老化3 d后，或被2% CaSO₄或10%膨润土污染后，体系仍具有较好的流变性。该钻井液还具有较好的抑制性，对钠基膨润土岩心的线性膨胀降低率达94%以上；对于现场的泥页岩岩屑的滚动回收率均能达到95%以上。钻井液的这种较好的封堵性、润滑性、抑制性、低表面张力等有利于维持井壁稳定、润滑防卡、保护储层等，适用于复杂情况较多的深井及大位移井。现场试验表明，该钻井液体系可以降低井底复杂情况，缩小井径扩大率，缩短建井周期，满足了安全、高效、环保钻井的需要，具有很好的推广应用前景。 

Study and Application of a New High Performance Water Base Drilling Fluid XZ

A new high performance water base drilling fluid, XZ, has been developed for use in drilling the costly deep wells in the Junggar Basin. The formulation of the drilling fluid, based on "plugging, inhibiting, solidifying, duel repellent, and lubricating" principles, was conducted with several additives, such as a bionic inhibitive agent XZ-YZJ, a bionic plugging agent XZ-FDJ, a lubricant XZ-RHJ, a solidifying filming agent XZ-CMJ and a duel repellent agent XZ-SSJ etc. This drilling fluid has good rheology and is resistant to long-term aging and to contamination. After being aged for 3 d or being contaminated with 2% CaSO4 or 10% bentonite, the mud still maintains good rheology. Swelling test with the drilling fluid on Na-bentonite cores showed that the rate of swelling of the cores was reduced by more than 95%, and roller oven test with drilled cuttings from a well site showed that cuttings recovery was greater than 95%, indicating that the drilling fluid has satisfactory inhibitive capacity. Good plugging performance, lubricity, inhibitive capacity and low surface tension of the drilling fluid are beneficial to borehole stabilization, lubricity, pipe sticking prevention and reservoir protection, rendering the drilling fluid adaptability to the drilling of deep well and deep extended-reach well which are characteristic of more downhole troubles. Field application demonstrated that the new drilling fluid is able to help in reducing downhole troubles, minimizing rate of well enlargement, and reducing time needed for well construction. The application of this drilling fluid has satisfied the needs for safe, efficient and environmentally friendly drilling operations, indicating that the drilling fluid has a bright future in finding wide applications.