摘要
对塔西南超深井钻井过程中出现的微纳米裂缝与孔隙渗漏的问题进行分析,发现现有钾基聚磺钻井液中的封堵剂不能有效封堵微纳米裂缝与孔隙。为提高封堵粒径级配,在室内制备一种石蜡微乳液,通过粒径比较法得出了最佳制备方案。方案表明制备的最佳比例为“S+A”∶石蜡=9∶1,最佳搅拌速度为1400 r/min,最佳温度为120℃。制备得到的石蜡微乳液D_(50)粒径在2.9μm左右,单分散颗粒尺寸在200~300 nm左右,表面张力在45.0~47.5 mN/m范围内,稳定时间长达30 d。采用石蜡微乳液对塔西南区块钾聚磺水基钻井液体系进行优化,从优化结果可以看出,石蜡微乳液的配伍性好;优化后钻井液体系表观黏度降低3.5 mPa·s;钻井液的滤失量减小3.5 mL;泥饼厚度减小1 mm,增强了钻井液的滤失造壁性能。采用压力传导法对石蜡微乳液的封堵性能进行评价,结果表明石蜡微乳液可以提高封堵承压能力,石蜡微乳液优化钻井液对克孜洛依组致密砂岩的封堵率为58.4%,具有较好的微纳米裂缝孔隙封堵能力。
Analyses of seepage losses through micron and nanometer fractures and pores encountered in ultra-deep drilling in the southwest Tarim Basin show that the plugging agents in the potassium based polymer sulfonate drilling fluid are unable to effectively plug these fractures and pores. To improve the particle sizing for better plugging, a paraffin microemulsion was developed in laboratory. The optimum conditions for the development of the microemulsion was determined through particle size comparison method. It was found through experiment that the optimum quantity ratio of “S+A” : paraffin is 9:1, the optimum agitation speed is 1400 r/min, and the optimum reaction temperature is 120 ℃. The microemulsion thus prepared has D_(50)particle size of about 2.9μm, monodisperse particle sizes between 200 nm and 300 nm, surface tension between 45.0 mN/m and 47.5 mN/m, and stable time up to 30 d. The potassium based polymer sulfonate drilling fluid was then optimized with the microemulsion, and good compatibility between them was seen after mixing. The optimized drilling fluid has its apparent viscosity reduced by 3.5 mPa·s, filtration rate reduced by 3.5 mL, thickness of mud cake reduced by 1 mm, and the filtration and wall building performance of the drilling fluid was enhanced. Evaluation of the plugging capacity of the paraffin microemulsion by pressure transmission methos shows that the paraffin microemulsion can be used to improve the pressure bearing capacity of the formation;test of the paraffin microemulsion on plugging the Keziluoyi dense sandstone shows that 58.4% of the microfractures and pores were plugged, indicating that the paraffin microemulsion has good plugging capacity.
作者
宋瀚轩
叶艳
周志世
张焊钰
张謦文
周福建
郭继香
SONG Hanxuan;YE Yan;ZHOU Zhishi;ZHANG Hanyu;ZHANG Qingwen;ZHOU Fujian;GUO Jixiang(China University of Petroleum,Beijing,Beijing 102249;PetroChina Tarim Oilfield Company,Korla,Xinjiang 841000)
出处
《钻井液与完井液》
CAS
北大核心
2022年第5期550-557,共8页
Drilling Fluid & Completion Fluid
基金
国家自然科学基金“多孔介质中纳米颗粒与发泡剂协同构建Pickering泡沫机制及其运移规律”(ZX20200280)
塔里木油田项目“英沙、玉龙区块地层特性与钻井液技术对策研究”(201019121044)。
关键词
石蜡微乳液
超深井
钻井液
封堵
优化
压力传导
塔里木
Paraffin microemulsion
Ultradeep well
Drilling fluid
Plug
Optimize
Pressure transmission
Tarim
