一种新的气井井身结构在苏里格气田的应用

Application of a new gas wellbore structure in Sulige Gasfield

长庆苏里格气田的成功开发历经了井身结构优化、特殊工艺井技术试验和以PDC钻头复合钻井技术为核心的快速钻井3个重要阶段.随着钻井工艺技术的不断进步,平均井深3 441 m的直井钻井周期由原来的平均36 d缩短至目前13 d左右,丛式定向井平均钻井周期逐步降至目前的20 d以内.钻井速度的提高空间逐步减小,而降低材料成本的技术再次引起人们的关注,为了应对国际金融危机带来的负面影响,进一步降低钻井成本,首次在苏里格气田采用Φ88.9 mm无油管完井技术试验了两口井,这种新的气井井身结构可以节约生产套管费用,降低钻完井成本.

The fast drilling technique of Changqing Sulige Gasfield experiences the three important stages,including the optimization of wellbore structure,the well test with special technology and compound drilling technique with PDC.With the gradual improvement of drilling technology,the drilling cycle of the wells with the average vertical depth of 3 441 m is gradually shortened from 36 days before to 13 days at present,the average drilling cycle of the cluster directional wells is reduced to 20 days at present.There is a little of increasing space of drilling velocity.Therefore,the technique of reducing the material cost attracts our attention again.In order to deal with the negative affect caused by the international finance crisis,a new gas wellbore structure——the small hole and tubingless completion technology for deep well,is designed for decreasing the drilling cost.In the technoloty,the casing of Φ88.9mm is used and tubing is not needed.The technology is applied to two test wells in Sulige Gasfield,and the expense of $500 000 per well can be saved.