Technology research on high performance water-based drilling fluid for Jin 30 Well Area in Dongsheng Gas Field

Abstract:

Aiming at the complex problem of mudstone formation leakage and collapse in Liujiagou， Shiqianfeng and Shihezi Formations in Jin 30 Well Area of Dongsheng Gas Field， indoor rock analysis and physical and chemical performance tests are conducted， revealing that the mudstone formations have the characteristics of high clay mineral content， multi-scale fracture development， and are prone to clay hydration expansion and fracture expansion during drilling. A wellbore stabilization technology with the core of inhibiting clay hydration swelling and strengthening multi-scale fracture plugging is proposed. Through the verification of indoor research and field application， effective control of hard and brittle mudstone in the long open hole sections is realized by the developed multi-salt ratio high-performance compound salt drilling fluid， and the wellbore stability is significantly improved. Compared to the year 2023， the drilling period of horizontal wells with pilot hole in the year 2024 was shortened by 37.4%， which provides technical support for efficient drilling in mudstone formation in Jin 30 Well Area of Dongsheng Gas Field. The research results also provide theoretical basis and practical reference for oil and gas exploration and development under similar geological conditions.