考虑烃源岩非均质性的排烃模型

烃源岩组构参数中的源岩厚度对排烃效率的影响较大,利用烃源岩连续厚度和最大有效排烃厚度的相对关系可将源岩分为完全排烃和不完全排烃两种类型。异常压力的发育程度和空间分布特征决定了幕式排烃的空间分布。结合异常压力与烃源岩组构的分布情况将有效烃源岩排烃地质模型划分为:完全排烃模型、不完全排烃模型和幕式排烃模型。将烃源岩非均质性的概念引入到生、排烃数值模拟过程中,利用韵律层的概念,推导出这3种排烃地质模型的数学模型。经牛38井一段烃源岩的计算检验,结果表明新模型提高了计算精度。

A study on hydrocarbon expulsion model considering heterogeneity of source rocks

Thickness, among the structural parameters of source rocks, has relatively large influences on hydrocarbon expulsion efficiency. Source rocks can be divided into complete expulsion and incomplete expulsion types, according to the relative relation between the continuous thickness and the maximum effective expulsion thickness of source rocks. The development and spatial distribution features of abnormal pressures determine the spatial distribution of episodic expulsion. Based on the distribution of abnormal pressure and structural parameters of source rocks, the geologic models of effective source rocks can be divided into complete expulsion model, incomplete expulsion model and episodic expulsion model. The mathematical models of these 3 kinds of hydrocarbon-expulsion geologic models are derived from the concept of rhythmic layering and source rock heterogeneity. Actual calculation of the source rocks in Niu-38 well verifies that the new models improve the accuracy of calculation.