渝西区块龙马溪组强封堵油基钻井液技术研究

Research on Oil-based Drilling Fluid Technology for Strong Plugging of Longmaxi Formation in West Chongqing Block

钟成旭 李道雄 李郑涛 谢刚 张震

ZHONGChengxu LIDaoxiong LIZhengtao XIEGang ZHANGZhen

中国石油西南油气田公司页岩气研究院, 四川 成都 610041 西南石油大学石油与天然气工程学院, 四川 成都 610500

Shale Gas Research Institute, Southwest Oil and Gas Field Branch, CNPC, Chengdu, Sichuan 610041, China Petroleum Engineering School, Southwest Petroleum University, Chengdu, Sichuan 610500, China

渝西区块龙马溪组在水平段钻进过程中因井壁失稳而导致的卡钻、憋顶驱、测井困难等复杂情况频发，研究发现，造成此现象的主要原因是该区块龙马溪组地层微纳米孔、缝发育和钻井液封堵性能不足。因此，在强化现场钻井液封堵性能的基础上优选了钻井液主要处理剂，构建了适用于该区块龙马溪组强封堵油基钻井液体系，室内测试结果表明，经过220 nm和450 nm微孔滤膜时未发生滤失，且综合性能均优于普通钻井液。现场应用表明，龙马溪组水平段钻进过程中未出现井壁失稳问题，与同平台采用常规封堵技术的已钻井相比，平均机械钻速提高8.81 m/h，水平段钻井周期缩短2.79 d，铂金靶体钻遇率100$%$，创渝西区块深层页岩气井5项钻井指标纪录，强封堵油基钻井液技术能满足该区块钻井工程需要。

In the process of drilling in the horizontal section of Longmaxi Formation in west Chongqing Block, complicated situations such as sticking, roof flooding and logging difficulties occurred frequently due to the instability of borehole wall. Through research, we found that the main reasons for this phenomenon are the development of micro-nano pores and fractures and the insufficient plugging performance of drilling fluid in the Longmaxi Formation in this block. Therefore, on the basis of strengthening the plugging performance of the field drilling fluid, the main treatment agent of drilling fluid was selected, and the strong plugging oil-based drilling fluid system suitable for the Longmaxi Formation in this block was constructed. The laboratory test results showed that no filtration occurred when the 220 nm and 450 nm microporous filtration membranes were passed, and the comprehensive performance was better than that of ordinary well pulp. After field application, no borehole instability occurred in the drilling process of the horizontal section of Longmaxi Formation. Compared with those drilled on the same platform using conventional plugging technology, the average mechanical drilling rate increased by 8.81 m/h, the gesteerable drilling period of horizontal section borehole was shortened by 2.79 d, and the platinum target drilling rate was 100$\%$, setting five drilling indexes records for deep shale gas wells in the west Chongqing Block. It shows that strong plugging oil base drilling fluid technology can meet the needs of drilling engineering in this block.

10.11885/j.issn.1674-5086.2022.06.07.02