渝西大安区块超深层页岩气水平井钻井提速关键技术研究

Research on key technologies for speeding up drilling of ultra-deep shale gas horizontal wells in Da’an block， western Chongqing

摘要:

针对大安区块超深层页岩气水平井钻井过程中存在难钻地层机械钻速低、旋转导向仪器高温下的故障率高和钻井周期长等技术难点，以大安页岩气高效快速开发为目的，分析了钻遇地层特征和钻井技术难点，通过井身结构优化、高效钻头优选、“铂金靶体”快速识别、水平段降密提速、油基钻井液地面降温、抗高温白油基钻井液体系及等壁厚螺杆技术等技术研究和使用，形成了大安区块超深层页岩气水平井优快钻井技术。该技术在渝西大安区块大安104H超深层页岩气水平井进行了现场试验，实际完钻井深6789 m，水平段长2406.13 m，平均机械钻速10.60 m/h，较区块平均机械钻速8.12 m/h提高30.54%。结果表明，超深层页岩气水平井钻井提速技术可为大安页岩气高效开发提供技术支撑。

Abstract:

In response to the technical difficulties in ultra-deep shale gas horizontal well drilling in the Da’an block， such as low mechanical drilling speed in difficult drilling formations， high failure rate of rotary steering instruments at high temperatures， and long drilling cycles. In aim of efficient and rapid development of Da’an shale gas， the characteristics of encountered formations and technical difficulties in drilling were analyzed. Through the technical research and application such as optimization of wellbore configuration， selection of efficient drill bits， rapid identification of “Platinum targets”， density reduction and speed increase in the horizontal section， surface cooling of oil-based drilling fluid， high-temperature resistant white oil-based drilling fluid system， and equal wall thickness screw technology， the optimal and fast drilling technology for ultra-deep shale gas horizontal wells in the Da’an block was formed. This technology was tested on-site in the Da’an 104H ultra deep shale gas horizontal well， where the actual drilling depth was 6789m， with a horizontal section length of 2406.13m and an average mechanical drilling speed of 10.60m/h， which is 30.54% higher than the average value of 8.12m/h in the block. It can provide technical support for the efficient development of shale gas in Da’an.