邛西南断高须二气藏早期动态特征与排水采气方式分析

ANALYSIS OF THE EARLY DYNAMIC PERFORMANCE AND DRAINAGE GAS RECOVERY OF XUJIAHE 2 GAS RESERVOIR IN THE SOUTH HORST FAULT OF QIONGXI STRUCTURE

邛西构造须二气藏,是继川西中坝、平落坝须二气藏后发现的又一中丰度整装气藏。气井产量分布不均、生产受地层水影响较大。对不同射开程度和不同完井方式的4口井生产动态特征分析表明:气藏裂缝水窜不可避免,水窜严重影响气井产能;气藏水体能量有限;同时射开气水层,变气水两相渗流为气水单相渗流加两相管流,降低了水侵对气体渗流的影响。通过气水合采机理分析,结合气藏气水分布特征,提出采用多井同时射开气水层排水采气,有利于提高气藏开发效果。

Xujiahe 2 gas reservoir in Qiongxi structure is a middle-abundance and mono-block are after the discovery of Zhongba and Pingluoba Xujiahe 2 gas reservoirs in west Sichuan.Gas wells in the reservoir are characterized by uneven production and unstable production influenced by formation water.Analyzing the dynamic performance of 4 wells with different perforation degree and completion pattern indicates that water channeling occurs in fractures inevitably,water channeling affects gas-well deliverability greatly and aquifer in reservoir is limit.Gas/water layers are perforated,simultaneously gas-water-phase flow changes to single-phase flow and two-phase conduit flow.As a result,the influence of water invasion on gas percolation becomes less.Based on the mechanism of gas-water recovering and the distribution of reservoir gas-water,we present that it is favorable for gas reservoir to develop drainage gas recovery by perforating gas-water layers simultaneously.