石油钻采工艺2017，Vol.39Issue(5)：588-593,6.DOI:10.13639/j.odpt.2017.05.011
四川盆地页岩气水平井B环空带压原因分析与对策
Causal analysis and countermeasures on B sustained casing pressure of shale-gas horizontal wells in the Sichuan Basin
摘要
Abstract
In the Sichuan Basin, the percentage of shale gas wells with sustained casing pressure (SCP) is higher, bringing about the challenges to the efficient development of gas reservoirs and the wellbore integrity of gas wells. In this paper, the actual SCP situa-tions in domestic shale gas development blocks were analyzed specifically. The gas source was determined by using the isotope analysis method, and SCP mechanisms of shale gas wells were studied by means of physical simulation experiment. Accordingly, the failure laws of cement sheath in different cement slurry systems in the process fracturing were figured out, and the key technologies to improve the sealing capacity of cement sheath and relieve the SCP phenomenon in staged fracturing wells were developed. When the cement slurry column can structurally satisfy the sealing requirement completely, a cement slurry system of low porosity and Young's modulus was developed by means of the interphase filling technique and the set cement porosity decreasing method. Its Young's modulus is only 4.2 GPa, and its porosity is 27.1% (the porosity of conventional cement set 35%). And the elastic deformation capacity of cement set is en-hanced dramatically. The new cement slurry system has been practically applied in 5 wells. And its high-quality cementing rate is 100% with no SCP. This research provides the good reference for SCP control.关键词
环空带压/页岩气井/固井/水泥浆/分段压裂Key words
sustained casing pressure/shale gas well/cementing/cement slurry/staged fracturing分类
能源科技引用本文复制引用
陶谦,陈星星..四川盆地页岩气水平井B环空带压原因分析与对策[J].石油钻采工艺,2017,39(5):588-593,6.基金项目
国家重大专项示范工程"彭水地区常压钻井及高效压裂工程工艺优化技术"(编号:2015ZX05069-002) （编号:2015ZX05069-002）
中石化科技攻关项目"改善天然气井水泥环长期密封性技术研究"(编号:P14112). （编号:P14112）
