常规稠油化学驱模拟油气摩尔分数场的方法

SIMULATING METHOD OF THE PETROLEUM MOLE FRACTION FIELD IN CHEMICAL FLOODING FOR CONVENTIONAL HEAVY OIL

化学驱模拟器CMG提供的由黑油模型向化学驱模型自动转换工具由于不能转换多套PVT，存在转换后模型中油气摩尔分数场为常数而无法体现原油性质分布差异的问题。应用Lasater公式，建立了溶解气油比、原油相对密度、摩尔质量分布与油气组分摩尔分数场之间的关系，从而获取化学驱模拟器中所需的油气组分摩尔分数分布场，再根据获取的摩尔分数场准确表征地下原油性质的分布。经过渤海某油田实际模型验证，计算结果准确可靠，能有效避免模型转换后流体性质非均质性表征不准的问题。

The current chemical flooding simulator CMG can provide the tool to automatically convert the Black Oil Model to chemical flooding model, but it cannot convert multiple sets of PVT. Therefore, the problems are resulted in constant petroleum mole-fraction field in the post-conversion model and furthermore the differential in crude oil properties＇distributions cannot be displayed. With the help of Lasater Formula, the relations among the dissolved gas-oil ratio, relative density of the crude oil, distribution of mole mass and oil-gas compositions＇ mole fraction field are established, and then the needed later can be obtained for the chemical flooding simulator; furthermore according to the field, the distributions of crude oil properties can be accurately characterized. Through the verification of prac- tical model of one of Bohai Oilfields, the calculations are accurate and reliable, and moreover the method can effec- tively avoid the problem of inaccurate characterization of fluid heterogeneity after the conversion of the models.