第37卷第5期 2016年10月
文章编号：1001-3873(2016)05-0519-05
新疆石油地质
XINJIANG PETROLEUMGEOLOGY DOI:10.7657/XJPG20160504
Vol. 37,No.5 Oet.2016
沧东凹陷孔二段致密砂岩储集层微观孔喉结构特征
程秋萌，陈世悦，鄂继华
（中国石油大学地球科学与技术学院，山东青岛266580）
摘要：应用薄片观察、场发射扫描电镜、物性分析、压汞分析和激光共聚焦显微镜观察等手段，对激海湾盘地黄葬墩陷沧东凹陷孔店组二授致密砂岩储集层岩石学特征、储集空间类型、储集层物性及孔喉分布特征进行了研究。结果表明，孔二段储集层主要为岩屑石英砂岩和岩屑砂岩，储集空间以次生溶蚀孔隙和晶间微孔隙为主，含少量残余原生孔隙和裂缝，平均孔隙度为7.71%，平均渗透率为0.59mD，属于特低孔超低渗储集层。储集层的孔喉结构较差，孔喉多呈孤立状分布，连通性较差。储集层的孔隙半径相差不大，多数为100-200μm；喉道半径相差较大，多属于微米一纳米级别。储集层的渗流能力主要受喉道半径、频数及分布形态的控制。对孔二段致密砂岩储集层的开发应采取保护喉道的改造工艺，才能取得更好的开发效果。
关键词：游海湾盆地；黄骅墩陷；沧东凹陷；孔店组；致密砂岩；储集层；孔喉结构；孔喉参数
中图分类号：TE112.23
文献标识码：A
Characteristics of Micro-Pore Throat Structures in Tight Sandstone Reservoir of the Second
Member ofKongdianFormation in Cangdong Sag
CHENG Qiumeng,CHEN Shiyue, YAN Jihua
(School of Geosciences, China University of Petroleum, Qingdao, Shandong 266580, China)
Abstract: Based on thin section observation, analysis on SEM, physical property and mercury injection and laser scanning confocal micro scope observation, the petrological characteristics, reservoir space type, physical property and pore throat distribution are studied for the tight sandstone reservoir in the second member of Kongdian formation in Cangdong sag of Huanghua depression, Baohai Bay basin. The re-sult shows that the reservoir in the second member of Kongdian formation is dominated by lithic quartz sandstone and lithic sandstone, and the reservoir space is mainly composed of secondary dissolved pores and intercrystalline micro-pores, containing a few residual primary pores and fissures. The porosity and permeability of the reservoir average 7.71% and 0.59 mD, respectively, indicating that the reservoir be longs to super-low porosity and extra-low permeability reservoirs, The reservoir pore throats have relatively poor structures and are mostly distributed separately, so the pore connectivity is poor. The reservoir pore radiuses are similar with the most ranging from 100 to 200 μm Pore throat radiuses vary largely with the most in micron-nano scale. The filtration capacity of the reservoir is mainly controlled by radius, frequency and distribution pattern of pore throats, Some treatment technologies should be adopted to protect the pore throats in the tight sandstone reservoirs in the second member of Kongdian formation and better development effects can be gained.
Keywords: Bohai Bay basin; Huanghua depression; Cangdong sag; Kongdian formation; tight sandstone; reservoir; pore throat structure;
pore throat parameter
随着勘探开发技术的不断进步，致密砂岩储集层在油气勘探中已经取得了突破性的进展。致密砂岩一般指孔隙度小于10%，空气渗透率小于1mD(基质渗透率小于0.1mD)的砂岩"。由于致密砂岩储集层的储集物性极差，储集空间多样，孔喉结构复杂，因此勘探开发的难度和风险较大。沧东凹陷古新统孔店组二段是盆地内主要的烃源岩和致密油聚集层段。孔二段致密砂岩普遍发育微米一纳米级孔隙，前人对于孔二段砂岩的研究多集中于沉积相和成岩作用等方面，对储集层尤其是孔喉结构的研究较为薄弱。孔喉特征研究有利于明确孔二段储集层的储集性能及其后期改
收稿日期：2016-03-31
修订日期：2016-0521
基金项目：国家自然科学基金（41372107）
造。GX井、GY井和WZ井是沧东凹陷内3口致密油气藏重点探井，均连续取心，为致密砂岩储集层的研究奠定了基础。笔者应用薄片分析、扫描电镜、激光共聚焦显微镜观察和压汞测试等技术手段，对孔二段致密砂岩孔喉结构特征进行精细表征，以期对沧东凹陷孔二段致密砂岩储集层评价及油气勘探开发有所借鉴。
区域地质概况
沧东凹陷位于渤海湾盆地黄骅坳陷南部，是大港油田第二大富油凹陷，勘探面积4700km，夹持于徐黑凸起和沧县隆起之间，北接孔店凸起，为一个南西
作者简介：程秋萌（1991-），男，辽宁盘锦人，硕士研究生，沉积及储层地质，（Tel)15153291763(E-mail)527326917@qq.com 万方数据