中文摘要：

通过分析西非深水油田钻井液技术难点,针对钻井液低温流变性调控与井眼清洗问题、气体水合物的生成与控制以及活性泥页岩井壁失稳问题,提出了相应的技术对策,构建了新型深水高性能水基钻井液体系.实验评价表明,该钻井液具有较低的黏度和较高的动切力,φ6 读数保持在7-10,有利于井眼清洗;钻井液流变性受低温影响较小,2 ℃和25 ℃的表观黏度比和动切力比分别为1.28 和1.10.该钻井液在不同层位的泥页岩岩样回收率均在90% 以上,抑制性明显优于以往使用的KCl-PHPA 钻井液体系,且在动态和静态条件下均具有优良的水合物抑制效果,抗污染能力强,满足西非深水油田钻井液技术需求.

英文摘要：

Via the analysis on technical dififculties of drilling lfuid for deepwater oil ifeld in the West Africa, in the light of the low-temperature rheological property regulation of drilling lfuid, borehole cleaning, gas hydrate generation and control, and borehole instability of active mud shale, corresponding technical countermeasures have been raised, and a new deepwater high-performance water-based drilling lfuid system has been established. According to the experimental evaluation, the drilling lfuid has relatively low viscosity and relatively high dynamic shear force, andφ6 reading is maintained at 7 to 10, which is beneifcial for the borehole cleaning; the rheological property of drilling lfuid is slightly affected by low temperature; the apparent viscosity ratio at 2℃ and the dynamic shear force ratio at 25℃ are respectively 1.28 and 1.10. The drilling lfuid recovery rate of mud-shale rock sample at different positions is more than 90%. The inhibition of drilling lfuid is obviously superior to that of previously-used KCl-PHPA drilling lfuid system, and has excellent hydrate inhibition effects under dynamic or static conditions. It still has strong anti-pollution capacity, and basically meets the technical requirements of drilling lfuid for deepwater oil ifeld in the West Africa.