梨树断陷致密承压封堵钻井液技术研究

Study on Pressure Bearing and Tight Plugging Drilling Fluid Technology in Lishu Fault Depression

为解决梨树断陷硬脆性泥页岩地层井壁失稳的问题,根据多元协同井壁稳定理论,提出了以柔性封堵剂配伍刚性封堵剂来提高钻井液封堵能力的技术对策,构建了致密封堵钻井液体系。性能评价结果表明,该钻井液体系可将泥页岩的渗透率降低至95%以上,抑制性能优异。在梨6-11HF进行了现场试验,钻井过程中均未出现井壁失稳现象,试验井段平均井径扩大率仅为8.94%,电测均一次成功。

In order to solve the problem of borehole instability of hard brittle mud shale formation in Lishu fault depression,according to the theory of multi-component cooperative borehole stability,the technical countermeasures of combining flexible plugging agent with rigid plugging agent to improve the plugging ability of drilling fluid were put forward,and the tight plugging drilling fluid system was constructed.Performance evaluation results showed that the drilling fluid system can reduce the permeability of mud shale to more than 95%,with excellent inhibition performance.The field test was carried out in Li 6-11HF well,and no borehole instability occurred in the drilling process.The average borehole diameter expansion rate of the test well section was only 8.94%,and the electric measurement was successful once time.