东濮凹陷页岩油气富集条件

Enrichment condition of shale oil and gas in Dongpu Depression

文中立足于东濮凹陷勘探实践,在岩心观察、有机地化和镜下薄片等资料分析的基础上,总结了页岩油气的富集条件.富集泥页岩发育决定了页岩油气的主力层位,东濮凹陷沙河街组沙三中、下为页岩油气最富集的层位,有机碳质量分数高,主要为Ⅱ1和Ⅰ型干酪根,热演化程度适中（Ro为1％～2％）;沉积体系和有利岩相是页岩油气富集的重要因素,富集泥页岩主要分布在深湖—半深湖和前三角洲泥沉积体系中,其中的纹层状灰质泥岩岩相储集空间发育程度和油气富集程度均高,是最有利的岩相类型.脆性矿物体积分数和裂缝发育程度是页岩油气富集的关键,东濮凹陷脆性矿物体积分数超过60％,有利于裂缝的形成及后期压裂改造;盐岩及异常高压的发育是东濮凹陷页岩油气保存的重要原因.运用多因素叠合法预测沙三中4-5、沙三中8、沙三下1-2是最有利的勘探层位,濮卫和柳屯—海通集洼陷是最有利的目标区,并部署实施卫68-1HF等井,取得初步成效.

Shale oil and gas are the important types of future resource potential.This paper summarizes the enrichment conditions of shale oil and gas based on the exploration practice of Dongpu Depression,core observation,organic geochemistry and microscopic sections analysis.The development of enriched shale determines the main layers of shale oil and gas.Shale oil and gas are enriched in the middle-lower part of the third member of Shahejie Formation in Dongpu Depression,having high TOC and R. of 1％-2％,mainly Ⅱ1and Ⅰ type kerogen.Sedimentary system and favorable facies are the important enrichment factors of shale oil and gas.Shale oil and gas are mainly enriched in the deep lake facies to semi-deep lake facies and prodelta facies.The reservoir space development degree and oil and gas enrichment degree of grain layer calcareous mudstone facies are high,which are the most favorable facies types.The high volume fraction of brittle minerals and fracture development are the key of shale oil and gas enrichment.There are more than 60％ brittle minerals in Dongpu Depression,which is conducive to fracture formation and post fracturing.Salt rock and abnormal high pressure development are the important reasons of shale oil and gas preservation in Dongpu Depression.Using multi-factor superposition method,4-5 and 8 layers of middle interval and 1-2 layer of low interval are predicted as the most favorable exploration layers in the third member of Shahejie Formation.Pu-Wei sub-sag and Liuton-Haitongji sub-sag are the most favorable target areas.Preliminary results are obtained in Well Wei 68-lHF after implementation.