异常高压火山岩气藏物质平衡方程初探

针对异常高压火山岩气藏开发过程复杂、成本高、地质储量预测难问题,提出了一种计算异常高压火山岩气藏地质储量的方法,该方法全面考虑了物性参数和岩性参数随地层压力的变化,并将异常高压气藏岩石压缩系数回归成地层流体压力的函数,利用最小二乘法求解方程。实例分析表明,利用该方法计算的地质储量为24.308×108m3,与作图法获得的地质储量24.446×108m3相当,表明该方法可靠、有效,从而为异常高压火山岩气藏预测地质储量提供一定的理论依据。

On Material Balance Equation of Abnormal High Pressure Volcanic Gas Reservoirs

In allusion to the problems of complex process, high cost, geological reserves hard to be estimated during the development of abnormal high pressure volcanic gas reservoirs, a method for calculating the geological reserves in the abnormal high pressure volcanic gas reservoirs was proposed, in which the changes of physical property and lithologicalparameters were totally considered and the compressed coefficient of abnormal high pressure gas reservoir rocks was put into the function of formation fluid by retrogression, least squares method is used for solving the equation. The result of example analysis shows that the calculated geological reserves is 24.308×10~8m~3, it is equal to 24.446×10~8 m~3 calcu- lated with graphical method, higher than that of corresponding hydrostatic pressure, which results in the complicated exploratory process, much high cost and difficulty to estimate the initial gas in place. A new method for estimating the initial gas in place of over-pressured gas volcanic reservoir with matrix and fracture was proposed. This method considers the variation of fluid property and rock property with the decrease of pressure, it shows that the method is reliable, effective, and it provides a theoretical basis for predicting the geological reserves in the abnormal high pressure volcanic gas reservoirs.