砂体输导层油气运移速率新模型及其应用

New model for hydrocarbon migration rate in sandbody transport layer and its applications

运移速率是控制地质介质中油气等流体运移特征的重要参数,但目前仍未形成统一的速率模型来描述具有典型孔隙介质特征的砂体输导层中油气等流体的非线性渗流规律。基于现有常规的孔隙介质流体运移速率模型,结合油气运移的非线性动力特征,得到了砂体输导层油气运移速率新模型。以准噶尔盆地车排子地区沙湾组等输导层为例,验证了新模型的计算步骤、参数表征以及资源评价应用。研究结果表明,砂体输导层油气运移速率具有极强的非线性动力特征,运移速率随阻力梯度与动力梯度比的增加呈幂律减小,运移速率是动力机制与运聚量之间的关键环节,砂体输导层中油气运聚量受控于运移速率、等效输导通道以及充注时间,研究为砂体输导层中油气运移定量分析和资源潜力评价提供了新思路和方法。

The migration flux is a crucial parameter controlling the migration of hydrocarbon and other fluids in geological media,whereas there is no still unified rate model for describing non-linear flow of hydrocarbon and other fluids in sand⁃body transport layer with characteristics of typical porous media.Combining with the non-linear dynamics characteristics of hydrocarbon migration,we construct a new migration rate model for calculating the hydrocarbon migration rate in sand⁃body transport layers based on the main existing rate models of fluids in porous media.Moreover,taking transport layers of Shawan Formation etc.at Chepaizi area in Junggar Basin as an example,this paper illustrates the calculation steps,parame⁃ter characterization and resource evaluation application of the new model.The studies show that the hydrocarbon migration rate in sandbody transport layer has very strong non-linear dynamic characteristics.The migration rate,which is the key link between the dynamic mechanism and the migration and accumulation volume in sandbody transport layer,decreases as a power function with increase of the ratio of the resistance gradient to the dynamic gradient.The new model suggests the hydrocarbon migration and accumulation volumes in sandbody transport layers are controlled by the migration rate,the equivalent transport channel,and the charging time.The study provides a new analytical method for hydrocarbon migration analysis and resource potential evaluation in sandbody transport layers.