济阳坳陷古近系致密储集层孔喉结构特征与分类评价  

Pore throat structure and classification of Paleogene tight reservoirs in Jiyang depression,Bohai Bay Basin,China

作　　者：王永诗[1] 高阳 方正伟 WANG Yongshi;GAO Yang;FANG Zhengwei(Shengli Oilfield Company,Sinopec,Dongying 257000,China;Exploration and Development Research Institute,Shengli Oilfield Company,Sinopec,Dongying 257015,China)

机构地区：[1]中国石油化工股份有限公司胜利油田分公司,山东东营257000 [2]中国石油化工股份有限公司胜利油田分公司勘探开发研究院,山东东营257015

出　　处：《石油勘探与开发》2021年第2期266-278,共13页Petroleum Exploration and Development

摘　　要：综合利用铸体薄片、常规压汞、恒速压汞、微纳米级CT扫描等资料,研究了济阳坳陷古近系致密砂岩和砂砾岩孔喉结构特征并进行类型划分。首先利用铸体薄片资料分析致密储集层物质组成和结构特征,然后利用常规压汞、恒速压汞和微米级CT扫描等测试手段研究致密储集层的孔喉结构特征,并对10个孔喉结构参数开展系统聚类分析,结合分类结果与试油成果,建立古近系致密储集层的分类方案。研究认为,济阳坳陷古近系致密储集层具有大孔微喉的特征,孔隙为微米级,喉道为次微米级—纳米级,孔喉半径比变化较大。致密储集层的渗透性受喉道半径控制,孔隙与喉道半径差别越小、孔喉分布均值性越好,渗透性越好。不经过压裂改造措施就能够产出工业油流的致密砂岩和致密砂砾岩的孔喉半径均值的下限分别为0.6μm和0.8μm,需要经过压裂改造措施后才能够产出工业油流的储集层孔喉半径均值为0.2~0.6μm,孔喉半径均值小于0.2μm的储集层为现有压裂改造措施条件下的无效储集层。由此对不同类型致密砂岩和砂砾岩储集层进行分类评价,在勘探评价中得到良好应用。The pore throat structure characteristics of Paleogene tight sandstone and sandy conglomerate in the Jiyang depression are studied using cast thin section,conventional mercury injection,constant rate mercury injection and micro CT scanning data,and a reservoir classification scheme based on pore throat structure parameters is established.The material composition and structural characteristics of tight reservoirs are analyzed by casting thin section data.The pore throat structure characteristics of tight reservoirs are studied by conventional mercury injection,constant rate mercury injection and micro CT scanning.Ten pore throat structure parameters are analyzed by cluster analysis.Based on the classification results and oil test results,the classification scheme of Paleogene tight reservoirs is established.The Paleogene tight reservoirs in the Jiyang depression have the characteristics of macropores and microthroats,with pores in micron scale,throats in nano-submicron scale,and wide variation of ratio of pore radius to throat radius.The permeability of the tight reservoir is controlled by throat radius,the smaller the difference between pore radius and throat radius,and the more uniform the pore throat size,the higher the permeability will be.The lower limits of average pore throat radius for the tight sandstone and tight sandy conglomerate to produce industrial oil flow without fracturing are 0.6μm and 0.8μm,respectively.Reservoirs that can produce industrial oil flow only after fracturing have an average pore-throat radius between 0.2–0.6μm,and reservoirs with average pore throat radius less than 0.2μm are ineffective reservoirs under the current fracturing techniques.Different types of tight sandstone and sandy conglomerate reservoirs are classified and evaluated,which are well applied in exploratory evaluation.

关 键 词：孔喉结构 致密储集层 储集层评价 古近系 济阳坳陷 渤海湾盆地 

分 类 号：TE122[石油与天然气工程—油气勘探]