气体循环钻井定质量气体井筒延伸极限研究

RESEARCH ON WELLBORE ULTIMATE EXTENSION FOR FIXED GAS MASS IN GAS CIRCULATION DRILLING

气体循环钻井与常规气体钻井相比有着节约能耗降低钻井成本等优点,同时又与常规气体钻井有着很大的差别,表现在气体循环钻井是以一定质量的气体进行循环钻进,在钻进到一定深度(延伸极限深度)后必须对井筒进行气量补充,其工艺特点导致了井筒沿程参数随钻进发生的改变和关键点的选取与常规气体钻井有着根本的不同。文章针对气体循环钻井的工艺特点,结合定质量气体循环钻进井深-排量-动能的分析方法,提出了气体循环钻井定质量气体延伸极限的概念、判断标准并对其进行了分析,对现场施工有着积极的指导作用。

Compared with conventional gas drilling, gas circulation drilling has the advantages of energy saving and reducing drilling costs et al, but at the same time it also has some differences between the two techniques. For gas circulation drilling, it uses a certain fixed gas mass to drill, and then must resupply gas volume after drilling a certain deep(wellbore ultimate extension). These characteristics of gas circulation drilling led to the parameters change along the wellbore with drilling and the selection of key points were fundamental different from conventional gas drilling. Based on the technological characteristics of gas circulation drilling, combined with the analytical methods of H-Q-E(depth - displacement - kinetic energy)of fixed gas mass in gas circulation drilling, the conception and criterion of fixed gas mass ultimate extension were proposed, which has a positive role in guiding site operation.