广安地区须家河气藏产能主控因素与增产措施分析

Analysis of Technological Measures and Productivity Affecting Factors for Xujiahe Gas Reservoir in Guang'an Area

针对广安地区须家河组气藏具有低孔低渗、储层裂缝不发育、砂体连通性差,气井自然产能低等特征,从气藏沉积相特征、储层厚度、储层非均质性及测试回压等方面分析该气藏气井的产能影响因素以及采取的措施。结果表明,当储层平均孔隙度为12%时,储层厚度需14.36 m才可满足最低工业气流标准;在渗透率变差相同程度的条件下,井外圈渗透率变差半径越大,无阻流量越小,对产能影响程度越大;当渗透率变差程度为1/8时,如果井外圈渗透率变差半径达到100～150 m,则气井无阻流量下降约50%;在测试回压Pwf/PR≤80%时,计算误差小于10%。

Xujiahe gas reservoir in Guang＇ an area is characterized by undeveloped fractures , low porosity and low permeability , and low natural productivity of gas wells. The factors affecting productivity of producing gas wells in Xujiahe gas field, influence of sedimentary facies, formation thick, formation inhomogenous permeability and meas- uring pressure on productivity of gas well has been researched. Result shows that when the average porosity is 12% , the minimum thickness of reservoir should be 14.36 m. Under the same poorer permeability, when outside permeability radius is bigger, open flow capacity is smaller and affecting production bigger. When poorer permea- bility is 1/8, if outside radius is 100 - 150 m, the open flow capacity of gas well decreases about 50%. When tes- ting return pressure is Pwf/PR ≤80%, calculating error is smaller than 10%.