元坝超深水平井井身结构优化与轨迹控制技术

Optimization Technique of Drilling Design and Path Control About Ultra-deep Horizontal Well in Yuanba

元坝气田是世界上埋藏最深的海相酸性气田,其长兴组主力气藏具有埋藏超深、高温、高压、高含硫化氢、储层薄横向变化大、气水关系复杂等特征,常规直井、定向井产量低,方案设计采用水平井开发。该区钻井面临"硬、塌、卡、漏、喷、毒"等挑战,复杂事故多,施工难度大,安全风险高。为此,从地层三压力特征和实钻资料分析入手,研究提出利于封隔复杂井段的五开制井身结构方案和利于轨迹优化调整的常规定向钻具组合设计。所形成的井身结构优化和轨迹控制技术已成功应用于10口超深水平井,保证了方案部署井的安全顺利实施,实现了优快钻井和水平段长穿优质储层的目标,完钻井测试均获得了高产,创造了多项国内外钻井工程新纪录。

Yuanba gas field is the deepest marine sour gas field in the world. The main gas reservoir of Changxing group has characteristics of ultra-depth, high temperature, high pressure, high hydrogen sulfide, thin reservoir, great lateral change and complex gas-water relationship, etc. The production of conventional vertical wells, directional wells is low, so the design adopts the horizontal well development. The well drilling is faced with the challenges of hard rocks, borehole collapse ,jamming of drilling tool, mud loss, blowout, and hydrogen sulfide, etc. There are many complex accidents and high security risks in construction. According to the analysis of formation pressure and real drilling data, we decide on five section casing program design and conventional directional well bottom hole assembly. Optimization of deep well casing program and trajectory control technology have been successfully applied to 10 ultra-deep horizontal wells, ensuring the successful implementation of project deployment wells and reaching the goal of the optimized drilling and long horizontal interval extended to high quality reservoir. The drilling tests have obtained high yield, and created new records of drilling engineering at home and abroad.