孔隙砂岩气藏储量微积分计算方法

ESTIMATION OF RESERVES BY INFINITESIMAL CALCULUS FOR POROUS SANDSTONE GAS RESERVOIR

通过对常规储量计算方法的回顾，针对目前储量计算中存在的问题，以储量建模分析为基础，采用网格内插法和利用地震储层横向预测结果来建立储量参数场，从而完整地提出了砂岩气藏地质储量的微积分计算方法，并推导了其数学模型；以中原油区文２３气田为实例，通过对该气田的储量计算和分析，完善了其储量计算的方法和流程；还改变计算方法、井网密度和储量纵向计算单元等，对该储量计算方法的可靠性和稳定性进行了检验。结果表明，该方法不仅提高了计算精度，而且其计算结果不依赖于井网密度和纵向储量计算单元的变化，具有很好的稳定性。因为它充分考虑了储层的非均质特征和气藏的宏观形态，与经典容积法相比，其方法更先进，计算结果可信度更高，更适合于复杂地质条件和气田勘探开发不同阶段的储量计算需要。

Through reviewing the conventional methods for estimation of reserves,aimed at the problems left in the existing estimation of reserves,and based on the modeling analysis of reserves,the reserve parameter fields were set up by use of the grid interpolation method and the result of seismic reservoir lateral forecast,thus an infinitesimal calculus for estimating the reserves of sandstone gas reservoir was entirely proposed and its mathematical model was also derived. Taking Wen 23 gas field in Zhongyuan oil field as an example,through reserve estimation and analysis of the field,its reserve estimation method and procedure are perfected,and through changing the estimating method,well spacing density and vertical reserve estimation unit etc.,the reliability and stability of such reserve estimation method are verified.It is shown that not only such method enhances the calculating accuracy,but also the result calculated by it is independent of the change of the well spacing density and vertical reserve estimation unit etc.being of a good stability.Because of fully considering the heterogeneity of reservoir bed and the macroscopic shape of gas reservoir,as compared with the typical volumetric method,such method is more advanced,the creditability of the result caculated is great and it can meet the needs of the estimation of reserves for complicated geological conditions and various stages of gas field exploration and development.