塔河油田奥陶系风化壳卡取方法探讨

Discussion of Boundary Division of Ordovician Weathered Crust in Tahe Oilfield

塔河油田奥陶系风化壳上下部分为两套地层压力系统,风化壳以下地层压力系数较上部地层压力系数低。为避免二开中完井深进入奥陶系风化壳,发生井漏、卡钻等工程复杂情况,降低后期完井测试及油气生产不利影响,可采取标志层对比、沉积旋回对比、碳酸盐含量分析、岩性特征分析、钻时分析等5种准确现场录井风化壳卡取方法。

Ordovician weathered crust in Tahe Oilfield consists of upper and bottom formation pressure systerns with bottom formation pressure coefficient lower than the upper one. To avoid lost circulation and pipe sticking caused by completion depth into Ordovician weathered crust in the second spud in and decrease negative impact on later-period well completion test and oil-gas production, this paper proposes five methods for boundary division of weathered crust including marker bed correlation, sedimentary cycle correlation, carbonate content analysis, lithologic character analysis and drilling time analysis, achieving better application results.