四川盆地及周缘页岩气水平井钻井面临的挑战与技术对策

Challenges of Shale Gas Horizontal Well Drilling in Sichuan Basin and Its Vicinity and the Technical Countermeasures

摘要:

中国石化近几年在四川盆地及周缘页岩气勘探开发取得了重要进展。但该地区页岩气水平井钻井速度低、钻井周期长、成本高、成井质量不高，严重影响了该地区页岩气商业化勘探开发进程。系统总结了四川盆地及周缘的涪陵大安寨、涪陵龙马溪、彭水和建南等地区页岩气水平井钻井面临的主要问题：浅部地层出水空气钻井受限、定向段井眼尺寸大机械钻速低、井漏频繁、气体钻井易井斜以及水平段油基钻井液固井质量差。针对上述问题，从浅层水控制措施、泡沫定向钻井技术试验、井漏的预防与处理、空气钻井防斜打直工具研发、页岩气水平井固井对策以及“井工厂”钻井作业模式攻关与应用等6个方面提出了应对技术措施，为页岩气钻井技术攻关和现场施工提供了借鉴与参考。

Abstract:

In recent years, there has been a major breakthrough in shale gas exploration in Sichuan basin and its vicinity by SINOPEC, but the commercialization process of exploration and development is influenced by low penetration rate, long drilling cycle, high drilling cost and bad well completion quality in this area. In this article, the main challenges in shale gas horizontal drilling are summarized, air drilling limited by shallow formation water, low ROP due to large diameter of directed section, frequent circulation lost, hole deviation by air drilling and poor cementing quality in horizontal section with oil based drilling fluid. Aiming at the above challenges, the technical countermeasures are proposed in 6 aspects: shallow formation water control, test of directional drilling with foam drilling fluid, prevention and treatment for circulation lost, development of anti-deviation device for air drilling, cementing of shale gas horizontal well and research and application of multi-well pad drilling technology. All these can provide reference for the research on shale gas drilling technology and construction.