用于精细控压钻井的无机凝胶隔离塞的研制及现场试验

Development and Field Testing of a Gel Isolation Plug for Precise Managed Pressure Drilling

黎凌 卫俊佚 张谦

LI Ling WEI Junyi ZHANG Qian

油气田应用化学四川省重点实验室，四川 广汉 618300 中国石油集团川庆钻探工程有限公司钻采工程技术研究院，四川 广汉 618300 中国石油西南威远东页岩气作业分公司，四川 成都 610000 中国石油集团川庆钻探工程有限公司钻井液技术服务公司，四川 成都 610000

Key Laboratory of Applied Chemistry for Oil and Gas Fields, Guanghan, Sichuan, 618300, China Research Institute of Drilling and Production Technology, CNPC Chuanqing Drilling Engineering Co.Ltd., Guanghan, Sichuan, 618300, China CNPC Southwest Weiyuan East Shale Gas Operation Company, Chengdu, Sichuan, 610000, China Drilling Fluid Technology Service Company, CNPC Chuanqing Drilling Engineering Co.Ltd., Chengdu, Sichuan, 610000, China

针对精细控压钻井起下钻及完井过程中钻井液漏失严重的问题，基于无机水硬性胶凝理论、密实充填理论和固化增强理论，通过优选关键处理剂形成了一种用于精细控压钻井的无机凝胶隔离塞工作液。性能评价表明，该无机凝胶隔离塞工作液初始流动性和稳定性好，抗钻井液污染能力强，稠化时间可以控制在0.5~4.0 h，适用温度60~150 ℃；固化成段塞后抗压强度达8.02 MPa，胶结强度达1.39 MPa/m2，承压封气能力大于2.69 MPa/m，可钻性级值为1级。现场试验表明，该无机凝胶隔离塞工作液固化成塞后，可以有效封隔油气，保障精细控压钻井起下钻的安全。研究表明，无机凝胶隔离塞工作液固化成塞后抗气窜能力强，能有效封隔油气，解决了精细控压钻井起下钻过程中缺乏安全封隔的问题。

The application of precise managed pressure drilling technology in the Moxi-Gaoshiti and Xiachuandong areas of the Sichuan Province effectively solved such challenges as leakage and coexistence of blowout and lost circulation caused by narrow safety density window of drilling fluid.However, due to the absence of effective and safe packoffs in tripping operations and well completion, the lost circulation is serious and the well control risk is extremely high.Therefore, based on the inorganic hydraulic gel theory, dense filling theory and solidification strengthening theory, a working fluid gel plug for precise managed pressure drilling was developed by using key treatment agents.The performance evaluation results suggested that the initial flow performance and stability of the working fluid gel plug were good, the anti-drilling fluid contamination ability was strong.Further, the thickening time could be controlled within 0.5-4.0 h, and the applicable temperature was 60-150 ℃.After solidification of the gel plug, the compressive strength of gel plug achieved to 8.02 MPa, the bonding strength reached 1.39 MPa/m2, the pressure bearing capacity greater than 2.69 MPa/m, and the drillability value was 1.Field application results showed that with the working fluid solidified into a plug, the gel plug could effectively seal off oil and gas, and in that way ensure safe tripping during precise managed pressure drilling.

中国石油集团川庆钻探工程有限公司科研项目“钻井用凝胶隔段技术研究与应用” CQ2016B-12-1-3

https://doi.org/10.11911/syztjs.2018150