四川盆地大安寨段非常规储层的储集空间类型与评价  

Characteristics and evaluation of reservoir spaces of shale gas(oil)in Da'anzhai member of Ziliujing Formation in Sichuan Basin

作　　者：郑荣才[1] 郭春利[1] 梁西文[2] 常海亮[1] 卢炳雄[3] 

机构地区：[1]成都理工大学油气藏地质及开发工程国家重点实验室,成都610059 [2]中国石化江汉油田分公司勘探开发研究院,武汉430000 [3]钦州学院资源与环境学院,广西钦州535000

出　　处：《岩性油气藏》2016年第1期16-29,共14页Lithologic Reservoirs

基　　金：国家重大科技专项"四川盆地岩性油气藏富集规律与目标评价"(编号:2011ZX05001-005)资助

摘　　要：四川盆地下侏罗统自流井组大安寨段是储层较致密和勘探难度较大的层系。以野外剖面及钻井岩心描述、薄片鉴定和场发射扫描电镜分析为基础,结合岩相古地理、测井和孔渗等资料,研究了大安寨段的储层特征,确定其为特低孔、特低渗裂缝-溶蚀孔、洞、缝型非常规储层,位于浅湖介壳滩与半深湖—深湖过渡带的湖坡为有利储层的发育相带,储集空间由不同尺度的各类裂缝,溶蚀孔、洞、缝,粒缘孔(或缝)、粒内孔和晶间孔等次生孔隙,以及泥页岩中的纳米—微米级有机质孔(或缝)和黏土矿物层间孔(或缝)组成。储层发育条件可归结为"层、相、位"三要素:"层"要素为区域分布较稳定的大二亚段,其厚度较大,泥页岩中有机质与脆性矿物含量均较高和基质岩中纳米—微米级有机质孔与黏土矿物层间孔(或缝)均较发育;"相"要素为黑色泥页岩与介壳灰岩不等厚互层组合的湖坡相带,该相带在成岩过程中因差异压实作用往往可形成分布较密集的成岩压裂缝;"位"要素为多类型与多期次破裂作用和溶蚀作用追踪叠加发育的部位,该部位是大安寨段致密储层中相对优质储层的分布位置,即大安寨段页岩气(油)非常规储层勘探与开发的"甜点"位置。It is generally accepted that the Da＇ anzhai member of the Lower Jurassic Ziliujing Formation in Sichuan Basin is tight reservoir and has great difficulties in prospecting. Based on the description of field sections and drilling cores, analysis of thin sections and FESEM, the reservoir characteristics of Da＇anzhai member were studied in combination with the data of lithofacies paleogeography, logging, porosity and permeability. It is identified that the Da＇anzhai member is a typical unconventional reservoir with ultra-low porosity and permeability, and the reservoirs have fracture-dissolved pores, caves and fractures. The lake slope facies between shallow lake shell beach and semi- deep and deep lacustrine are favorable for reservoir development. The reservoir space is composed of different sizes of various fractures, dissolved pores, caves and dissolved fractures, grain boundary pores （fracture）, intragranular dissolved pores, intercrystalline pores and so on, as well as nm-p.m level organic pores （fracture） and interlamination pores （fracture） of clay minerals. The development conditions of reservoirs can be summarized as three major elements of ＂layer, facies and position＂. The layer element refers to the second sub-member, which has stable regional distribution, large thickness, high content of organic matters and fragile minerals in mud shale and well-developed nm-μm level organic pores and interlamination pores （fracture） of clay minerals in substrate rock. The facies element refers to the lake slope facies belt composed of interbedded black shale and shell limestones with uneven thickness. in which high-density fi＇actures formed during the diagenesis stage due to differential compaction. The position element refers to where muhi-type and multi-stage fracture and dissolution diagenesis were superposed, it is the location of relatively high quality reservoir in the tight reservoirs, and is also the ＂sweet spot＂ of the oil shale gas （oil） in l）a＇ anzhai member.

关 键 词：页岩气(油) 非常规储层 储集空间 湖坡相带 储层评价 大安寨段 四川盆地 

分 类 号：TE122.23[石油与天然气工程—油气勘探]