四川盆地龙王庙组气藏白云岩储层孔洞缝分布特征  

Distribution characteristics of dolomite reservoir pores and caves of Longwangmiao Fm gas reservoirs in the Sichuan Basin

作　　者：高树生[1] 胡志明[1] 安为国[1] 刘华勋[1] 李海波[1] 

机构地区：[1]中国石油勘探开发研究院廊坊分院

出　　处：《天然气工业》2014年第3期103-109,共7页Natural Gas Industry

基　　金：国家科技重大专项(编号:2011ZX05004-005);中国石油重大勘探专项"四川盆地乐山-龙女寺古隆起含油气评价及勘探配套技术研究"(编号:2012ZD01-03-01)

摘　　要：四川盆地下寒武统龙王庙组气藏的储层岩性为白云岩,主要储集空间为溶蚀孔洞,微裂缝发育,非均质性极强,气藏的开发风险大,对其孔洞缝分布特征的研究是气藏开发方案编制的基础.为此,以MX13井岩心样品为研究对象,系统地测试了白云岩储层孔隙度、渗透率和密度,并进行了相关性分析.运用CT扫描与核磁共振技术研究了储层孔、洞、缝的分布特征与规律,进而综合分析了龙王庙组白云岩储层特征及其对储量评价和开发动态的影响.结果表明：龙王庙组白云岩储层克氏渗透率介于0.001～2 mD,平均为0.32 mD;孔隙度介于2％～10％,平均为4.62％,超过60％的储层孔隙度小于6％,其对应的渗透率一般也小于0.1 mD,具有基岩孔渗低、非均质性强、孔洞缝发育的特征;中孔以上的储集空间达到了90％,储层既有较大的储集空间,又有一定的渗流能力.Natural gas was found mainly stored in corroded pores and caves in the Lower Cambrian Longwangmiao Fm dolomite gas reservoirs in the Sichuan Basin.The developed micro fissures and great heterogeneity of the reservoirs make gas exploration in this study area quite risky.To this end,our research into the distribution characteristics of dolomite reservoir pores and caves lays a foundation for decision making in gas exploration there.First,focusing on the core samples from the Well MX13,we presented the systematic test and made correlation analysis of the porosity,permeability,and density of the dolomite reservoirs.Then,we applied the computed tomorgraphy scan （CT scan） and nuclear magnetic resonance （NMR） technologies to the study of the distribution characteristics and rules of the reservoir pores,caves and fissures,followed by the analysis of characteristics of the dolomite reservoirs and their influence on the reserves evaluation and exploitation dynamic performance.Finally,the findings were concluded as follows：the intrinsic permeability of Longwangmiao dolomite reservoirs ranges from 0.001 to 2 mD at an average of 0.32 mD; the porosity ranges from 2 to 10％ at an average of 4.62％,the porosity of over 60％ of the reservoir pores is less than 6％ and accordingly their permeability is generally less than 0.1 mD.To sum up,such bedrocks are characterized by low permeability,great heterogeneity and developed fissures; the large reservoir space of mesopores with certain filtration capacity reaches 90％.

关 键 词：四川盆地 早寒武世 白云岩 孔洞 裂缝(岩石) 孔隙度 渗透率 CT扫描 核磁共振 渗流能力 

分 类 号：P618.13[天文地球—矿床学]