延长东部浅层煤层气水平井井下固井工具附件可靠性实验探索

Experimental Exploration on Reliability of Downhole Cementing Tool Attachment for Shallow Horizontal Wells in Yanchang Coalbed Methane East

延长气田东部区域煤层埋深浅、存在低压、易漏失层,该区域内的煤层气井在固井过程中易发生地层破裂、水泥浆漏失现象,井下固井工具附件可靠性直接影响固井质量。本文从固井技术难点分析出发,对于可靠性较高的弹簧球式浮箍浮鞋、固井碰压关井阀等设备完成仿真模拟分析及性能试验;研发的碰压关闭式浮箍,提高了工具可靠性。设计工具附件组成固井管串结构,现场应用2口水平井,结果表明优选的固井工具附件能够满足浅层大位移水平井固井施工的技术要求。

The coal seam in the east area of Yanchang Gas field is buried in shallow depth,with low pressure and easy to leak layer.Coalbed methane wells in this area are prone to formation fracture and cement mud leakage during ce-menting process,and the reliability of downhole cementing tools and accessories directly affects the cementing quality.In this paper,from the analysis of cementing technical difficulties,for the high reliability of the spring ball type float hoop float shoes,cementing pressure shut-in valve and other equipment completed simulation analysis and performance tests;The high reliability of the tool is improved by the collision-pressure closing float hoop.The tool accessories were designed to form a cementing pipe string structure,and two horizontal wells were used in the field.The results show that the preferred cementing tool accessories can meet the technical requirements of shallow extended reach horizontal well cementing construction.