摘要
河南中牟和温县页岩气区块在直井钻井过程中频繁出现坍塌掉块、井径扩大等井下复杂,通过对储层地质特征以及老井钻井液体系测试分析,造成此现象的主要原因为钻井液封堵性不足。因此基于抑制水化、加强封堵两方面开展钻井液研究,优选封堵剂HSM、HGW和抑制剂HAS,形成一套强封堵、强抑制钻井液体系,并对体系性能进行了测试。室内测试结果表明,该钻井液体系性能优良,100℃老化72 h仍具备较好的流变性;对泥页岩钻屑热滚回收率高达98.5%,10 h线性膨胀率仅为2.34%;封堵性能好,6 h API和HTHP滤失量分别为7.8 mL和9 mL;还具备较强的抗污染能力。现场应用后基本未发生坍塌掉块、井壁失稳现象,井径扩大率从21%降至6%,说明该钻井液体系能够满足该区块的钻井工程需要。
Downhole troubles such as borehole wall collapse and hole enlargement were frequently encountered during shale gas vertical drilling in Zhongmou county and Wen county, He’nan. Analyses of the geological characteristics of the reservoirs and test on the drilling fluids used in offset wells showed that the occurrence of the downhole troubles came from the lack of plugging capacity of the drilling fluid used. Based on this idea, studies were conducted on the formulation of the drilling fluid, focusing on the inhibitive capacity and plugging capacity of the drilling fluid. Two plugging agents, HSM and HGW, and a shale inhibitor HAS were selected to formulate the drilling fluid. Laboratory test of drilling fluid showed that it had good rheology after aging for 72 h at 100 ℃. Percent recovery of shale cuttings in hot rolling test was 98.5%. 10 h linear swelling rate of an artificial shale core tested with the drilling fluid was only 2.34%. 6 h API and HTHP filtration rates were 7.8 mL and 9 mL, respectively, indicating good plugging performance of the drilling fluid. The drilling fluid was also resistant to contamination. In field application, a well drilled with this drilling fluid experienced no borehole wall collapse and sloughing, percent hole enlargement was reduced from 21% to only 6%, proving that the drilling fluid has satisfied the needs of drilling operations in the blocks in question.
作者
袁青松
冯辉
张栋
李中明
代磊
董果果
YUAN Qingsong;FENG Hui;ZHANG Dong;LI Zhongming;DAI Lei;DONG Guoguo(He’nan Geological Survey Institute, Zhengzhou, He’nan 450001;Industrial Technology Innovation Strategic Allianceof Underground Clean Energy Exploration and Exploitation, Zhengzhou, He’nan 450001;He’nanYukuang GeologicalExploration Investment Co. Ltd., Zhengzhou, He’nan 450001)
出处
《钻井液与完井液》
CAS
北大核心
2019年第1期29-35,共7页
Drilling Fluid & Completion Fluid
基金
国土资源部第二轮页岩气探矿项目"河南中牟页岩气勘查"(GT2012YQTKQCR0020)
河南省重大科技专项项目"河南页岩气勘查开发及示范应用研究"(151100311000)
关键词
河南
页岩气
井壁稳定
钻井液
强封堵
强抑制
He’nan
Shale gas
Borehole wall stabilization
Drilling fluid
Strong plugging
Strong inhibition
