柴达木盆地深井五阀一封地层测试工艺

Formation testing technology with five valves and one packer for deep wells in Qaidam basin

柴达木盆地深井常采用尾管悬挂完井,井筒密闭性能不能满足APR地层测试需求,存在环空漏失严重、阀件开关异常的问题。立足现有测试工具和测试工艺技术,通过优化管柱结构、减少关井次数,利用RD压力测试阀、RDS循环阀、RD循环阀不同的操作压力,设计出满足一开一关井要求的五阀一封地层测试工艺。该工艺优选RTTS封隔器,优化各测试阀破裂盘开启压力级差,在井下工具失效时采用备用阀完成开关井动作,实现试油全过程压力数据记录,并顺利起出井内全部管柱。经K4井等多口井的应用,五阀一封地层测试工艺成功率达到100%。该工艺为高温高压深井地层成功测试提供了借鉴。

The deep wells in the Qaidam Basin are often completed with liner suspension,the wellbore sealing performance cannot meet the requirements of APR formation testing,and there are problems of serious annular leakage and abnormal valve switching.Based on the existing testing tools and technologies,by optimizing the structure of the pipe string,reducing the number of shut-ins,and using the different operating pressures of the RD pressure testing valve,RDS circulation valve,and RD circulation valve,a formation testing process with five valves and one packer was designed to meet the requirements of once well opening and shut-in.This process chooses RTTS packer,and optimizes the opening pressure difference of the rupture disk in each testing valve.When the downhole tool fails,the backup valve will take action to complete the well switching operation,to realize the pressure data recording of the whole process of oil testing,and to smoothly pull out all the pipe strings in the well.After the application of many wells such as Well K4,the success rate of the formation testing process with five valves and one packer has reached 100%.This process provides a reference for the successful testing of high-temperature and high-pressure formations in deep wells.