保压密闭取芯技术在ST1井的应用

The Application of Pressure Maintaining and Sealing Coring Technology in Well ST1

青海油田风险探井ST1井钻探目的在于探索三湖地区未成岩泥岩气领域勘探潜力,评价其岩芯在地层原始压力状态下油、气、水含量,同时开展各项分析化验建立泥岩气评价标准,对于涩北气田勘探潜能有重要意义。针对涩北气田取芯井段地层疏松、泥岩发育,取芯收获率保障难度大,设计了新型保压密闭取芯工具,并优化了取芯施工参数,使其更能适应油页岩地层。在保证岩芯收获率、保压率的前提下,缩短了作业周期。

The purpose of the risk exploration well ST1 in Qinghai oilfield is to explore the potential of the unconsolidated shale gas field in Sanhu area,evaluate the oil,gas,and water content of its core under the original pressure state,and establish shale gas evalu-ation standards by various analysis and testing.It is a great signifi-cance for the exploration potential of the Sebei Gas Field.In view of the loose formation and developed mudstone in the coring well section of Sebei Gas Field,which makes it difficult to guarantee the coring yield,a new type of pressure maintaining sealed coring tool was designed,and the coring construction parameters were op-timized to make it more suitable for Oil shale formation.On the premise of ensuring the core recovery rate and pressure retention rate,the operation cycle has been shortened.