南堡潜山油气藏小井眼开窗侧钻技术

Window side-tracking in slim hole well of Nanpu buried-hill hydrocarbon reservoirs

南堡潜山油气藏因埋藏深,导致井身结构复杂、钻井周期长、成本高,为进一步提高勘探开发效益,开展了老井?177.8 mm套管开窗侧钻二开次完井试验工作。NP280C井是南堡油田第一口?177.8 mm套管开窗侧钻潜山井,该井开窗侧钻点深、二开次完井井眼尺寸小,给开窗侧钻作业带来诸多难题。通过优选深层套管开窗侧钻工艺、小井眼扩眼技术、膨胀尾管悬挂器+直连套管完井方案,探索出一系列钻完井技术对策,保证了NP280C井套管开窗侧钻作业的成功实施。为南堡油田深层潜山老井重复利用提供了技术支持,也为同类油气藏老井侧钻施工提供了技术借鉴。

Nanpu buried-hill hydrocarbon reservoirs are buried deeply. This results in that wells drilled to develop these reservoirs have complicated borehole structure, longer drilling time and extremely high cost. To further enhance economic performances of oil exploration and development, tests for window side-tracking completion in existing ？177.8 mm casing were conducted. Well NP280 C is the first well with window side-tracking in ？177.8 mm in the Nanpu Oilfield. Significant window side-tracking depth and smaller sizes in borehole of the second completion brought multiple challenges to window side-tracking operations. By selecting optimal window sidetracking processes for casing in deep formation, slim hole expansion techniques and completion with expandable tailpipe hanger＋direct connection with casing, a series of drilling and completion techniques have been developed to guarantee successful implementation of casing window side-tracking in Well NP280 C. These techniques may provide necessary technical support for re-vitalization of existing wells for deep buried-hill reservoirs in Nanpu Oilfield and may also provide technical references for side-tracking operation in existing wells in similar reservoirs.