南海某高温高压气田丛式井表层大尺寸井眼防碰技术

ANTI-COLLISION TECHNOLOGY FOR SURFACE LARGE-SIZE SECTION OF CLUSTER WELLS IN SOUTH CHINA SEA

海上油气田通常以丛式井方式开发,井数多、井口密集、井槽间距小。南海某气田地层压力梯度变化大、台阶多,其井身结构较复杂,表层660.4 mm井段进行集中批钻作业时井眼碰撞风险高。文章介绍了南海某气田表层钻井防碰的技术难点,针对性提出表层大尺寸井眼综合防碰技术对策,并深入分析各项技术的关键点。该项技术在南海某气田表层井段作业中得到成功应用,安全高效地化解了防碰压力,可为以后类似的海上丛式井表层钻井防碰提供技术参考。

Offshore oil&gas fields are usually developed by cluster wells with the characteristic of dense wellheads and small space between wells.The pressure gradient of gas field in South China sea varies greatly with many pressure steps and relatively complex well casing program,all of which probably lead to high risk of wellbore collision while batch drilling the 660.4mm surface section.In this paper the difficulties of anti-collision while surface drilling are introduced,the comprehensive anti-collision technology for surface large-size wellbore put forward,and the key points of the technique analyzed.The technology has been successfully applied in the gas field,effectively avoided the well collision,and provided a technical reference for drilling operations of the similar wells.