川西坳陷苏码头构造蓬莱镇组储层特征及评价

Reservoir Characteristics and Evaluation of the Upper Jurassic Penglaizhen Formation in Sumatou Structure,Western Sichuan Depression

在整理与分析岩心、薄片、扫描电镜、测井、物性测试等资料的基础上,对蓬莱镇组储层的储集性能及孔隙结构进行了综合研究,从成因上阐述了储层发育的控制因素,并对储层进行了分级与评价。认为:蓬莱镇组储层岩石类型以长石岩屑砂岩为主,物性表现为低孔、低渗、高含水饱和度的"两低一高"特点;储集空间由原生粒间孔隙和次生粒间孔隙组成,微裂缝不甚发育;压实、胶结、次生加大、交代等破坏性成岩作用对储层形成不利;环边绿泥石的发育减少了孔隙损失;来自下伏烃源层混相涌流之酸性水的溶蚀作用,形成粒间溶孔、粒内溶孔、铸模孔等蓬莱镇组的主要储集空间;上侏罗统蓬莱镇组储层为低孔—低渗(Ⅰ类)、特低孔—超低渗(Ⅱ类)储层,部分发育致密储层(Ⅲ类),该组天然气主要产出于Ⅰ-Ⅱ类储层中。

Both reservoir property and porous structure of Penglaizhen Formation reservoir were studied based on some data from core,thin section,electronic microscope scanning,well logging and physical property.In addition,some origin factors affecting reservoir development were also explored origin and the reservoir was classified and evaluated.This study shows that:(1) the reservoir with poor developed microfracture,is mainly composed of feldspar-debris sandstone,its physical properties are characterized by two lows and one high(i.e.,low porosity,low permeability and high water saturation),its reservoir space contains both primary and secondary intergrannular pores;(2) such destructive diagenesis as compaction,cementation,secondary enlargement and metasomatism brings about a bad effect on reservoir forming;(3) the development of chlorite around reservoirmay reduce pore loss;(4) the main reservoir spaces in Penglaizhen Formation,such as intergrannular dissolution pore,intragrannular dissolution pore and mould pore,are formed by acid dissolution from overlying source bed;and(5) the Upper Jurassic Penglaizhen Formation is featured by low-porosity and low-permeability(type Ireservoir) extrapartly additionally,andreservoirs.in the formation is mainly produced from reservoir),low-porosity and extra low-permeability(type II type I-type IInatural gas poor developed(type III reservoir),additionally, natural gas in the formation is mainly priduced from type I-type II reservoirs.