靖边气田储层水锁对气井产能影响分析

The Effect of Reservoir Water Locking on Gas Well Productivity in Jingbian Gasfield

针对靖边气田气井作业和生产过程中,由于水基工作液侵入或生产中地层水、凝析液在井底聚集,使井筒附近储层含水饱和度上升,导致储层气相渗透率降低,气井生产能力变差的情况,通过开展毛细管自吸率、毛细管自吸量分析,进一步深化了对储层水锁效应的认识,并结合平面径向渗流模型和实例分析,基本掌握了水锁对靖边气田气井产能的影响。

During the gas well operation and production process,because of the invasion of water-based drilling fluid or the accumulation of formation water and condensed liquid on the bottom of well,water saturation in the vicinity of wellbore was raised,gas permeability in the reservoir was reduced(which was called water locking effect).After water-lock effect was produced,capillary resistance was raised in the gas-water interface of rock porosity,and Jiamin effect was caused,an additional flow resistance was induced to the original normal seepage flow of natural gas in formation.The gas flow capacity was reduced then,which would result in the serious decline of gas well productivity.Therefore,timely cleaning wellbore liquid in gas well operation and its production would greatly reduce the damage to the reservoir,reduce the impact of water lock effect on gas well productivity.