深层火山岩气藏压裂直井复合渗流产能模型

COMPOSITE SEEPAGE PRODUCTIVITY MODEL OF THE FRACTURED VERTICAL WELL IN DEEP VOLCANIC GAS RESERVOIRS

为准确表征深层火山岩气藏压裂气井产能,在稳定渗流理论基础上,分别考虑压裂直井裂缝内外不同的非线性渗流特征,建立了压裂直井复合渗流产能预测模型。研究表明,启动压力梯度、高速非达西和应力敏感作用是影响产能的主要因素,滑脱效应影响程度有限,随着生产压差的增大,启动压力梯度对产能影响程度不断减小,高速非达西和应力敏感对产能影响程度不断增加。典型实例计算表明,该模型计算无阻流量与实际无阻流量误差为6%,满足应用要求。

In order to accurately characterize the fractured well productivity in deep volcanic gas reservoirs,based on the stable seepage theory,considering the different non-linear flow characteristics within and outside the fractures of the fractured well,the composite seepage productivity model of the well was established. The research shows that the start-up pressure gradient,high-speed non-Darcy and stress sensitivity actions are the key factors of influencing the productivity,while the influence of the slippage effect is limited,with the rise of the production pressure differential,the influenced degree of the start-up pressure gradient is continuously decreased,while the ones of the high-speed non-Darcy and stress sensitivity are just on the contrary. The typical case calculation shows that with the help of the model,the calculated error between the open flow potential and actual open flow capacity is only 6%,this achievement can meet the requirements of the application.