裂缝有水气藏无因次水侵量计算模型参数优化

Optimizing parameters in dimensionless water-invasion calculation model of fractured water-drive gas reservoirs

针对目前四川盆地有水气藏水侵分析方法实用性偏差及计算精度较低等问题,开展基于非稳态水侵问题的无因次模型参数优化方法研究。该方法综合无因次非稳态水侵量计算和水驱气藏物质平衡方程,采用实际生产数据与预测结果拟合反馈修正预设水体参数,旨在提高水侵动态分析和水体计算的准确性。将该方法应用于四川盆地某气藏生产井的产水实例,对实例区域应用该方法构建局部水体,通过建立单井数值模型的方式论证该方法的有效性及实际效果。研究结果表明:①无因次水侵量计算模型参数优化方法可以降低由模型参数设计偏差导致的计算结果多解性;②显著提高水体计算和水侵动态分析的准确性;③对目前正在生产中的有水气藏的开发具有现实指导参考价值。

For most water-drive gas reservoirs, Sichuan Basin, many existing approaches for analyzing water invasion are disadvantageous with poor practicality and low calculation accuracy. So, another method to optimize parameters in a dimensionless model based on unsteady water invasion was studied. This method combines dimensionless calculation of transient water-invasion rate with material balance equation of water-drive gas reservoirs, and adopts actual production data matching with prediction results to modify preset parameters of waterbody, which aim to be helpful for water-invasion performance analysis and increase calculation accuracy of waterbody. After its application to some production wells in a certain gas reservoir, Sichuan Basin, local waterbody was constructed and single-well numerical simulation was developed, all demonstrating its effective. Results show that(1) this optimization method can reduce computational multi-solutions caused by designed deviation of parameters for the dimensionless model;(2) it may be helpful for the water-invasion performance analysis and obviously increase the calculation accuracy of waterbody;and(3) it’s of practical significance to guide an development of water-drive gas reservoirs which are in course of production.