致密油资源富集区与“甜点区”分布关系研究——以美国威利斯顿盆地为例

Relationship between resource-rich regions and sweet spots for tight oils: A case study of the Williston Basin in the USA

张新顺 王红军 马锋 孙相灿 宋志慧

Zhang Xinshun Wang Hongjun Ma Feng Sun Xiangcan Song Zhihui

中国石油勘探开发研究院, 北京 100083

Research Institute of Petroleum Exploration & Development, PetroChina, Beijing 100083, China

通过对美国致密油成熟探区,威利斯顿盆地巴肯组致密油详细解剖研究,分析致密油资源富集区与甜点区的分布关系。基于948口钻测井数据,绘制多参数地质平面图,利用成因法、体积法和递减曲线法分别对盆地的致密油资源丰度进行评价,对比不同方法下资源丰度的差异,并结合地质参数平面图分析致密油甜点区的分布特征与规律。研究结果表明:威利斯顿盆地巴肯组优质烃源岩是致密油形成的先决条件;成因法和体积法评价的资源富集区与致密油甜点区分布差异较大,不能直接单独应用于甜点的预测;邻近资源富集区的过渡区,同时具备靠近生烃中心、具有地层超压、较高气油比、有一定构造幅度等多个相对有利的因素,是致密油甜点发育区;在构造上,这些过渡区往往发育在盆地斜坡区或靠近背斜等正向构造的翼部。

Tight oils from the Bakken Formation in the Williston Basin in the USA were studied to find out the relationship between the resource-rich regions and sweet spots for tight oils.Some maps with multiple parameters were drawn based on drilling and logging data from 948 wells.Genetic method, volume method and decline curves were used to evaluate the abundance of tight oils in the study area.The distribution of sweet spots was studied by comparing differences in abundance combined with geological data.The results show that high-quality hydrocarbon source rocks of the Bakken Formation were a prerequisite for the generation of tight oils.The resource-rich regions predicted by the genetic and volume methods clearly varied with the occurrences of tight oils, and could not be used individually in the prediction of sweet spots.The transitional region adjacent to the resource-rich regions had some favorable conditions for tight gas development, such as closeness to the hydrocarbon generation center, formation overpressure, high gas-oil ratio and tectonic setting.These transitional regions often developed in the slope zone of the basin or on positive structures such as anticlines.

国家科技重大专项(2011ZX05028-002)和中国石油重大科技专项(2013E-0501)资助。

https://doi.org/10.11781/sysydz201505619