红车拐地区百口泉组储层特征及控制因素

Reservoir characteristics and controlling factors of Baikouquan formation in Hongcheguai area

红车拐地区紧邻玛湖凹陷,区内百口泉组的油气勘探潜力巨大,但目的层储层相关特征认识模糊,阻碍勘探进一步深入。为了揭示红车拐地区百口泉储层特征及控制因素,本文通过岩心观察、相关岩石薄片分析(普通、荧光以及铸体)、扫描电镜、物性以及试油等资料,对百口泉组储层岩石学特征、储集物性、孔隙结构以及储集空间进行详细分析。结果表明:研究区百口泉组岩石类型以砂岩和砾岩为主,百二段以中岩屑砾岩为主,百三段以岩屑砂岩为主;储集层属于低孔特低-低渗类,含油性同物性呈正相关关系;百三段储层孔隙结构好于百二段储层的;储集空间主要为原生粒间孔,其次为次生孔隙和微裂缝,沉积微相和岩石组构对有利储层分布和储集质量有较大的影响,成岩作用中压实作用是储集物性较低的根本因素,胶结物以及沉积组分为后期溶蚀作用提供物质基础;古地貌控制有利储层平面展布,强烈挤压造成的异常压力和微裂缝有利于储集物性的改善。

Hongcheguai area is close to Mahu sag.Baikouquan formation in this area has great potential for oil and gas exploration,but the related characteristics of target reservoir are not well understood,which hinders further exploration.Through core observation,related rock slice analysis(ordinary,fluorescence and casting),scanning electron microscope,physical properties and oil testing,etc.,the petrological characteristics,reservoir physical properties,pore structure and reservoir space of Baikouquan formation ware analyzed in detail.The results showed that rock types of Baikouquan formation in the study area were sandstone and conglomerate,and the second member was composed mainly of medium rock-fragment conglomerate rock,while the third member was composed mainly of rock-fragment sandstone;The reservoir belonged to low porosity and ultra-low permeability,and there was a positive correlation between the oil-bearing property and the physical property;Pore structure of reservior in third member was better than that of the second member;The reservoir space was mainly primary intergranular pores,followed by secondary pores and micro fractures.Sedimentary micrefacies and rock fabric had large affection on favorable reservoir distribution of favorable reservoir and reservoir quality.Compaction was the basic factor of low reservoir physical property in diagenesis.Cement and sedimentary components provided material basis for later dissolution.The paleogeomorphology control was favorable for the plane distribution of reservoirs,and the abnormal pressure and micro fractures caused by strong compression were helpful to the improvement of reservoir physical properties.