Non-Darcy turbulence is highly likely to form in the well developed cracks in the volcanic gas reservior, so the Darcy law, suitable for the conventional gas reservoirs mostly with single media, doesn't apply to the volcanic gas reservoirs. Through the analysis of the flow experiment of volcanic gas reservoirs with CO2, and based on the fluid mechanics, this paper establishes the gas-water two-phase flow mathematical model in dual media under consideration of natural gas high-speed turbulence, and the flow law of gas in the model is in accord with the Foechheimer equation. Then the model is solved by using the finite difference method, and the numerical simulation program and software are programmed. The numerical simulation results of a single well in Changling Gas field show some differences under the consideration of high-speed turbulence, such as shorter time to stable yields, lower of the predicted final degree of recovery, the greater impact of high-speed turbulent with higher production pressure, and after the production pressure reached 8.9 Mpa, the effect decreased. When the actual production pressure was 6.65 Mpa, the predicted final degree of recovery decreased by 1.17%. Therefore, the impact of the high-speed turbulence has to be considered during the production of volcanic gas reservoirs.%针对火山岩气藏裂缝发育,裂缝内极易形成高速非达西紊流,而常规气藏的单一介质、达西渗流理论不适用于此类气藏的问题,通过对含CO2火山岩气藏流态实验分析,根据渗流力学基本原理,建立了考虑天然气高速非达西紊流渗流特征的双重介质气、水两相渗流数学模型.模型中气体渗流符合Forchheimer二项式方程,并采用有限差分方法对模型进行求解.利用长岭气田实际单井资料进行数值模拟研究表明:考虑裂缝高速紊流,稳产时间变短,预测期末采出程度降低；生产压差越大,高速紊流影响增加,压差达到8.9 MPa后,影响幅度降低；考虑生产压差6.65 MPa时,预测期末采出程度降低1.17％.因此,裂缝性火山岩气藏开发须考虑高速紊流的影响.
展开▼
