Journal of Southwest Petroleum University(Science & Technology Edition) ›› 2024, Vol. 46 ›› Issue (2): 103-113.DOI: 10.11885/j.issn.1674-5086.2022.06.07.02

• OIL AND GAS ENGINEERING • Previous Articles     Next Articles

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

ZHONG Chengxu1, LI Daoxiong2, LI Zhengtao1, XIE Gang2, ZHANG Zhen1   

  1. 1. Shale Gas Research Institute, Southwest Oil and Gas Field Branch, CNPC, Chengdu, Sichuan 610041, China;
    2. Petroleum Engineering School, Southwest Petroleum University, Chengdu, Sichuan 610500, China
  • Received:2022-06-07 Published:2024-05-11

Abstract: 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.

Key words: wellbore stability, oil-based drilling fluid, strong plugging, horizontal well, shale gas

CLC Number: