强絮凝钻井液在苏里格气田的试验应用

随着国家环境保护工作的进一步深入,地面泥浆池进行钻井液净化处理的方式将会被彻底取消,这就要求钻井液必须进行罐式循环。为提高罐式循环的钻井液净化效果、维持良好的钻井液性能参数,保障井下施工安全顺利,研制出了适合苏里格气田钻井现场用快速絮凝的强絮凝处理剂,并确定了强絮凝剂钻井液的配方。室内实验表明,在20 s的时间内,该钻井液能快速对浓度为100 kg/m3的膨润土浆进行有效絮凝沉降,使固液分离、实现净化目的,满足了钻井现场罐式循环钻井液净化的需要。该钻井液在S47-8-66H2井进行了现场试验应用,试验井段长1800 m,平均机械钻速为27.42 m/h,与2014年苏里格水平井直井段平均机械钻速23.00 m/h相比,提高了19.22%;该钻井液在罐式循环中成功地实现了良好净化,为苏里格气田钻井现场岩屑不落地的环境保护工作提供了很好的借鉴作用。 

The Application of Strongly Flocculent Drilling Fluid in Sulige Gas Field

As the environment protection requirements are becoming more stringent, mud pits for surface circulation of drilling fluid will be completely replaced by mud tanks with which the drilling fluid is circulated at the surface. To clean the mud effectively and efficiently with mud tank circulation, and maintain good drilling fluid properties to ensure safe drilling, a strong flocculent for fast flocculation used in Sulige gas field has been developed, and the formulation of a drilling fluid containing the flocculent is determined. In laboratory experiments, the formulated drilling fluid can effectively flocculate a 100 kg/m3 bentonite slurry in 20 s, finally separating the solids with the liquid. This drilling fluid was tried in the well S47-8-66H2. The length of the well using this drilling fluid is 1800 m, and the average ROP is 27.42 m/h. Compared with the average ROP, 23.00 m/h, obtained in drilling the vertical sections of horizontal wells in Sulige in 2014, an increase in average ROP of 19.22% has been realized. This drilling fluid can be well cleaned through surface tank circulation, providing successful experiences for environment protection through "no drilled cuttings on the ground" at the drilling site in Sulige gas field.