考虑束缚水时变的致密气藏数值模拟研究

发布时间：2019-02-16 06:46

【摘要】：从气相启动压力梯度的物理概念和物模实验角度分析认为,气体通过高束缚水低渗致密岩心时的"阈压效应"实质为气水相间渗流阻力的宏观反映,毛管压力曲线与时变的气水相渗曲线足以定量描述该现象,不应引入气相启动压力梯度。建立了考虑气水相渗时变、储层应力敏感及可动水启动压力梯度的致密气渗流数学模型,用全隐式有限差分方法求解,并编制了数值模拟器。对新模拟器进行了退化测试,并利用新模拟器研究了特殊渗流机理对致密气藏开发的影响及气水相渗时变对实际区块的影响,结果表明:不考虑特殊渗流机理时,新模拟器与Eclipse软件计算结果具有很好的一致性;气水相渗时变会增大气井产水量、减少稳产气时间;可动水启动压力梯度会减少日产水量、增加稳产气时间;储层应力敏感会降低日产水量、提早进入递减期;束缚水的运移是气井产水重要原因之一,考虑气水相渗时变更能反映实际气井生产动态。
[Abstract]:From the point of view of physical concept of gas phase starting pressure gradient and physical model experiment, it is considered that the "threshold pressure effect" of gas passing through high bound water and low permeability dense core is essentially a macroscopic reflection of the seepage resistance between gas and water phase. The capillary pressure curve and the time-varying gas-water phase permeation curve can describe the phenomenon quantitatively, and the gas-phase starting pressure gradient should not be introduced. A mathematical model of tight gas seepage with time-varying gas-water phase, sensitive reservoir stress and movable water starting pressure gradient is established. The mathematical model is solved by fully implicit finite difference method, and a numerical simulator is developed. The degradation test of the new simulator is carried out, and the influence of the special seepage mechanism on the development of the tight gas reservoir and the influence of the time-varying gas and water phase permeability on the actual block are studied by using the new simulator. The results show that the special seepage mechanism is not taken into account. The results of the new simulator are in good agreement with those of the Eclipse software. The time-varying permeability of gas-water phase will increase the water production of gas wells and reduce the time of stable gas production; the starting pressure gradient of movable water will reduce the daily water production and increase the stable gas production time; the reservoir stress sensitivity will reduce the daily water production and enter the decline period early. The migration of bound water is one of the important reasons for water production in gas wells.
【作者单位】：中国石油大学(华东)石油工程学院;中海石油(中国)有限公司上海分公司;
【基金】：“十三五”国家科技重大专项“厚层非均质性气藏产能评价及预测技术(编号:2016ZX05027-004-004)” 国家自然科学基金“页岩气藏多级压裂水平井流动特征及产能评价方法研究(编号:51374227)”;国家自然科学基金“致密储层体积压裂缝网扩展模拟研究(编号:51574265)”部分研究成果
【分类号】：P618.13

【相似文献】