稠油油藏蒸汽吞吐加热半径及产能预测新模型

A new model of steam soaking heating radius and productivity prediction for heavy oil reservoirs

蒸汽吞吐加热半径的确定是产能评价和动态预测的基础。常规加热半径计算方法均假设加热区为等温区,且等于蒸汽温度,而实际上加热区内地层温度是由蒸汽温度逐渐降低到原始地层温度。针对加热区内地层温度为非等温分布的这一实际情况,通过引入热水区前沿温度,构建了地层温度非等温分布模型,并在此基础上根据Marx-Langenheim加热理论建立了蒸汽吞吐加热半径计算模型和产能预测模型。利用所建立的模型对加热半径和产能进行计算的结果表明,Marx-Langenheim加热半径计算公式是该加热半径计算模型的一种特殊情况,新加热半径计算模型更具普适性;同时,产能预测模型计算结果与数值模拟计算结果基本一致,从而验证了模型的正确性。

The determination of steam soaking heating radius is the base for productivity evaluation and dynamic prediction.In conventional calculation methods of heating radius,heating area is assumed as isothermal region and has the temperature equal to steam temperature.In fact,the formation temperature in heating area gradually decreases from the steam temperature till the original formation temperature.Aiming at the actual situation that the formation temperature in heating area shows non-isothermal distribution,the non-isothermal distribution model of formation temperature was established by introducing the front temperature of heating area.On this basis,the calculation model of steam soaking heating radius and productivity prediction model were built based on Marx-Langenheim heating theory.The established models were used to calculate the heating radius and productivity.The results show that Marx-Langenheim equation is corresponding to a special case of the heating radius calculation model,and the new heating radius model has more widespread application.Meanwhile,the calculation results of productivity prediction model are basically consistent with numerical simulation results,thus verifying the correctness of this model.