长宁区块页岩气开发表层井眼轨迹优化设计

Surface Wellbore Trajectory Optimization Design for Shale Gas Development in Changning Block

长宁区块页岩气钻井施工中会遇到表层自然增斜严重、地层可钻性差、防碰稳斜段井斜较小、降斜井段易垮塌、钻井周期长及成本居高不下的难题。在分析该区块页岩气井眼轨迹原设计优缺点的基础上,进一步优化施工井布井方案、井眼轨道设计及钻井技术,提出了长宁区块页岩气开发表层施工井眼轨迹优化方案。该技术方案经过现场实践及应用,取得了良好效果,可显著提高机械钻速、缩短钻井周期,为长宁区块页岩气规模开发提供了技术支持。

There are many difficulties during the shale gas development and drilling process in Changning block, such as serious nature deviation angle of surface formation, poor drillability, small deviation in anti-collision and angle maintaining interval, collapse in the angle descending interval, long drilling period, high drilling cost, and so on. Based on the disadvantages analysis of the previous design plan, the well distribution plan, well trajectory design and drilling technology is further optimized for the cluster wells, and a new trajectory optimization scheme is proposed. The technology scheme has achieved good results through field test. The drilling speed has been improved obviously and the drilling period has been reduced significally, which provide technical support for the shale gas development in Changning block.