火山岩气藏气井生产动态规律及预测方法

与常规层状沉积储层不同，火山岩储层储集空间复杂多样，发育有不同规模尺度的孔缝组合方式，非线性渗流机理复杂，存在应力敏感、滑脱效应及“接力”排供气机理。受非线性渗流机理的影响，气井生产动态规律与常规储层气井差异较大。基于火山岩储层多尺度、多介质的特点，结合火山岩气藏非线性渗流机理，利用多个火山岩气藏气井实际生产动态资料，将气井的开发过程划分为初期高产、产量递减和低产稳产3个阶段，并运用Eclipse数值模拟技术对实际气井的生产动态进行拟合预测分析。在气井生产动态分析的基础上，考虑滑脱效应及应力敏感的影响，形成了气井生产动态预测方法，并对12口生产井产能进行拟合预测，其中有10口井的计算结果与实际生产情况相符。研究结果对预测气井产量、合理配产具有重要意义。

Production performance patterns and forecasting methods of gas well in volcanic gas reservoirs

Different from conventional sedimentary reservoirs,the storage space in volcanic gas reservoirs,with different-sized pore-fracture array modes,is quite complicated.The existence of stress-sensitivity effect,slippage effect,and relay gas supply mechanism leads to complex nonlinear percolation mechanism,with the influence of which,the dynamic production performance pattern of volcanic gas wells is quite different from that of the conventional gas wells.Based on characters of multi-size and multi-medium,and combining the dynamic production data from several volcanic gas wells,the study divides the well production performance into 3 phases:The initial high-production period,production-declining period,and low but stable production period.Numerical simulation of Eclipse,the history matching result of which perfectly fits the actual production curve,verifies the rationality of the “3-phase” theory.A production performance prediction method is built with slippage effect and stress sensitivity effect taken into consideration.On the basis of the research results,productivity of 12 wells are predicted,and 10 of them are in accordance with the actual situation.This study has great significance in volcanic gas wells production prediction and proration.