气藏水侵与开发动态实验综合分析方法

传统油气藏开发实验分析多从单因素角度研究气藏水侵及开发动态，不利于发挥物理模拟实验优势。结合水驱气藏开发实验实例，建立了气藏水侵与开发动态实验综合分析方法。从生产动态、水侵程度分析、动态压降剖面、含水饱和度及剩余储量分布5个方面对气藏开发机理和开发动态进行综合描述，论述了单因素分析方法产生偏差的原因，指出实验综合分析方法的优势及必要性。实例研究表明：由于室内模拟气井不受井筒积液影响，裂缝带上的气井长时间带水生产等效实现了排水采气，降低水的影响；存在贯通缝的气藏S3近井地带压力梯度稳定在0.22 MPa/cm，不到无贯通缝气藏S1和气藏S2的50%；气藏S3气水同产使水侵后气藏含水饱和度仅增加32.33%，较未带水生产井低10%以上；采收率提高20%以上；气藏不同部位水侵机理不同，水侵气藏由于受水封作用影响，储量动用极不均衡 。

Experimental analysis method for water invasion and development performance of gas reservoir

The single-factor analysis is often used in traditional experiments to carry out water invasion and development evaluation. Combined with the development experiment of water drive gas reservoir， the comprehensive analysis method of water invasion and development dynamic experiment of gas reservoir is established. Through the five aspects of gas well production performance， water invasion analysis， dynamic pressure drop profile， water saturation， and residual reserves distribution， this paper comprehensively evaluates the water invasion degree and development performance of gas reservoir. The reason of the error of the single factor analysis method is analyzed through the example， and the advantage and necessity of the experimental comprehensive analysis method are pointed out. The case study shows that： because there is no wellbore effect in laboratory gas wells， the long-term water production of gas wells in fracture zone objectively achieves drainage gas production and restrains water invasion； the pressure gradient in the near well zone in S3 is finally stable at 0.22 MPa/cm， less than 50% of water invasion gas reservoir S1 and S2； the increment of water saturation after water invasion in S3 is only 32.33%， which is about 10% lower than that in the non water production wells； the recovery factor increased by more than 20%； due to the influence of water sealing， the production of water drive gas reservoir is very unbalanced.