CAJ | 학술논문

通过岩心观察及岩石薄片鉴定，利用X-射线衍射、铸体薄片图像和扫描电镜等分析手段，结合大量的岩心孔渗数据，在研究陕北斜坡中部长2储层岩石学及物性特征的基础上，定性描述孔隙与定量分析孔隙构成相结合识别长2储层的主要孔隙类型，揭示孔隙特征，重点探讨这些主要孔隙类型的成岩作用控制机制。研究认为：长2储层整体上属于中孔低渗型细粒长石砂岩，多数孔隙中见绿泥石薄膜；主要发育粒间孔(包括残余粒间孔)、杂基内微孔、粒间溶孔、粒内溶孔(主要是长石、岩屑溶孔)、碳酸盐溶孔和晶间微孔等6类孔隙，其中粒间孔是最主要的孔隙类型，粒内溶孔是最主要的次生孔隙类型，杂基内微孔和晶间微孔的储渗意义不大；长21、长22储层的孔隙构成特征与长2储层的相似；粒间孔的保存主要受保持性成岩作用的控制，粒内溶孔主要是大气水淋滤作用的产物。早成岩阶段的自生绿泥石胶结、微晶石英胶结和碳酸盐矿物胶结都不同程度地保护了粒间孔；粒内溶孔则是与2次构造抬升剥蚀事件相对应的两期大气水淋滤作用的结果。
통과암심관찰급암석박편감정，이용X-사선연사、주체박편도상화소묘전경등분석수단，결합대량적암심공삼수거，재연구협북사파중부장2저층암석학급물성특정적기출상，정성묘술공극여정량분석공극구성상결합식별장2저층적주요공극류형，게시공극특정，중점탐토저사주요공극류형적성암작용공제궤제。연구인위：장2저층정체상속우중공저삼형세립장석사암，다수공극중견록니석박막；주요발육립간공(포괄잔여립간공)、잡기내미공、립간용공、립내용공(주요시장석、암설용공)、탄산염용공화정간미공등6류공극，기중립간공시최주요적공극류형，립내용공시최주요적차생공극류형，잡기내미공화정간미공적저삼의의불대；장21、장22저층적공극구성특정여장2저층적상사；립간공적보존주요수보지성성암작용적공제，립내용공주요시대기수림려작용적산물。조성암계단적자생록니석효결、미정석영효결화탄산염광물효결도불동정도지보호료립간공；립내용공칙시여2차구조태승박식사건상대응적량기대기수림려작용적결과。
By means of a core survey, rock section identification, of X-ray diffraction, rock cast section images and scanning electron microscope, combined with a large amount of porosity and permeability data of core and based on a study of petrology and physical property of Chang 2 reservoir, a qualitative description with a quantitative analysis was conducted to identify the pore components and main pore types; meanwhile, char-acteristics of these main pore types and their diagenetic controls were the focus in the middle part of North Shaanxi Slope. The research suggested that Chang 2 reservoir belongs to medium porosity, low permeability, fine arcose sandstone and chlorite coating is common in the sandstone. Six types of pore were observed and they are intergranular pore (residual intergranular pore), micropore in matrix, intergranular dissolved pore, intragranular dissolved pore (feldspar, rock fragment dissolved pore), carbonate dissolved pore and intercrystal micropore. Of them the intergranular pore is the most important pore type, intragranular dissolved pore is the most important secondary pore type, and the reservoir space and flow matrix of micropore in matrix and intercrystal micropore is inconspicuous. The pore component of Chang 21, Chang 22 reservoirs is similar to that of Chang 2 reservoir. Reservation of intergranular pore is controlled by retention processes. Intragranular dissolved pore is regarded as a result of atmosphere water eluviating. Autogenetic chlorite cement, microcrystalline quartz (silica) cement and carbonate mineral cement can preserve intergranular pore to a certain extent in the diagenetic stage. In-tragranular dissolved pore have resulted from two phrases of atmospher water eluviation corresponding to two tectonic uplift and denudation events.