薄层稠油藏溶剂辅助蒸汽驱产量预测模型

A Recovery Prediction Model for Solvent Enhanced Steam Flooding in Thin Heavy Oil Reservoirs

通过分析生产数据和数值模拟结果,将薄层稠油油藏溶剂辅助蒸汽驱生产过程分为蒸汽前缘垂向扩展阶段、蒸汽前缘水平扩展阶段及冷凝水产出阶段.针对每个生产阶段,通过联合质量守恒方程、运动方程、能量守恒方程及溶剂扩散方程得到描述蒸汽前缘扩展和产油量解析模型.能量守恒方程属于典型的第二类Volterra积分函数,首先对其进行Laplace变换;之后运用半解析方法对该模型进行求解.为验证模型的正确性,将模型的溶剂辅助蒸汽驱计算结果与数值模拟结果对比,整体误差仅为4%.新模型可以方便简单地分析不同溶剂性能和注采参数对溶剂蒸汽驱开发效果的影响.

With analyses of field production data and numerical simulations,solvent-enhanced steam flooding(SESF) production process is divided into three stages.By integrating mass conservation equation,energy conservation equation,motion equation and diffusion equation,a mathematical model was obtained to describe steam front development.The expression is a typical Volterra integral function of the second kind and could be transformed by Laplace transformation.It is solved by discretizing time and space into small intervals.With comparison of calculated results and those of STARS,relative error of less than 4% for whole process is found.The model provides an accurate and quick method for analyzing effects of solvent properties and injection strategies on SESF production process.