基于多尺度CT扫描的长岭凹陷青一段储层特征及渗流机理  

Reservoir characteristics and seepage mechanism of Qing 1 Member in Changling Sag based on CT scanning

作　　者：杨沛 胡望水[1,2] 崔莺莺 陈慧 古楠玲 赵铭 YANG Pei;HU Wangshui;CUI Yingying;CHEN Hui;GU Nanling;ZHAO Ming(School of Geosciences,Yangtze University,Wuhan 430100,China;Key Laboratory of Exploration Technologies for Oil and Gas Resources,Ministry of Education,Yangtze University,Wuhan 430100,China)

机构地区：[1]长江大学地球科学学院,湖北武汉430100 [2]长江大学油气资源与勘探技术教育部重点实验室,湖北武汉430100

出　　处：《断块油气田》2025年第2期211-220,共10页Fault-Block Oil & Gas Field

基　　金：国家自然科学基金项目“松辽盆地南部页岩油差异富集主控因素及机理”(41340030)。

摘　　要：基于CT扫描实验,从全直径、25 mm和2 mm 3个尺度对长岭凹陷青一段细粒沉积岩采用三维重构技术建立了不同尺度下的数字岩心,并统计分析了储层孔喉结构参数,开展了单相渗流模拟,建立了不同岩性的储层发育模式。研究表明:1)泥质粉砂岩和页岩裂缝发育,孔隙度较高且成岩矿物也较发育,能对储层起保护作用。2)细粒沉积岩储层孔隙半径均以小于2?滋m为主,含粉砂泥岩大孔喉较多,页岩次之,纯泥岩最差,孔喉形状均以三角形为主,但含粉砂泥岩孔隙形状相对规则。3)含粉砂泥岩在不同尺度下连通性均好,具备较强渗流能力,然而,纹层状页岩和含裂缝纹层状泥岩只能在大尺度下渗流,纹层状泥岩和粉砂质条带泥岩只在小尺度下连通性好。4)含粉砂泥岩以孔隙-裂缝型储层发育模式为主,大尺度下裂缝是渗流通道,小尺度下连通孔隙和喉道是渗流通道;页岩以中孔孔隙和裂缝作为储集空间和渗流通道;泥岩的储层发育模式受控于沉积构造和砂含量,分别发育裂缝型、裂缝-小孔型和小孔型3种模式。Based on CT scanning experiment,digital cores of fine-grained sedimentary rocks from Qing 1 Member in Changling Sag were constructed at three scales of full diameter,25 mm and 2 mm using three-dimensional reconstruction technique,and statistical analysis of reservoir pore-throat structural parameters was conducted,followed by single-phase seepage simulation to establish reservoir development models for different lithologies.The study reveals that:(1)Argillaceous siltstone and shale exhibit developed fractures,high porosity,and well-developed lithogenic minerals,providing protective properties to the reservoir.(2)Pore radius of fine-grained sedimentary rock reservoirs are mainly below 2μm,with silt-bearing mudstone having the largest pore-throats,followed by shale,and pure mudstone having the smallest.The pore-throat shapes are mainly triangular,though silt-bearing mudstone pores exhibit relatively regular shapes.(3)Silt-bearing mudstone exhibits good connectivity and strong seepage ability at different scales,however,shale and laminated fractured mudstone can only flow at large scales,and laminated mudstone and silty striped mudstones only show good connectivity at small scales.(4)Slit-bearing mudstone is dominated by the pore-fracture reservoir development model,with fractures as main seepage channels at large scales and interconnected pores and throats as seepage channels at small scales.Shale utilizes medium-sized pores and fractures as reservoir spaces and seepage channels,and the reservoir development model of mudstone is controlled by sedimentary structure and sand content,developing three models:fracture model,fracture-micro-pore model and micro-pore model.

关 键 词：孔喉结构 渗流机理 数字岩心 长岭凹陷 松辽盆地 

分 类 号：TE122[石油与天然气工程—油气勘探]