珠江口盆地白云凹陷深层储层特征与有效储层控制因素

珠江口盆地白云凹陷珠海组和恩平组是该区深层油气勘探的主要层系，查明深层储层基本特征和有效储层控制因素对于白云凹陷深层油气勘探具有重要意义. 基于岩石学和矿物学、成岩作用、孔隙特征及沉积相分析，明确了白云凹陷深层储层基本特征. 白云凹陷深层以低孔低渗和致密储层为主；压实作用是造成深层储层变差的主要原因，碳酸盐胶结和石英次生加大是主要的自生矿物；孔隙类型以粒间溶孔和粒内溶孔为主；有效储层以低孔低渗及以上储层为主，孔隙度总体保持在10%左右，渗透率变化范围大. 中粗粒沉积相带、溶蚀作用和超压是深层有效储层的主要控制因素. 中粗粒砂岩具有较好的原生孔和次生孔发育条件，渗透率较高，胶结减孔作用弱，溶蚀增孔作用强；溶蚀作用是深层关键的建设性成岩作用，溶蚀孔隙是深层主要的孔隙类型；超压传导作用有利于酸性流体活动和溶蚀物质的迁移，对形成溶蚀孔隙具有积极意义；分流河道和水下分流河道砂体是中粗粒砂岩的主要载体，应作为深层油气勘探的优选对象. 

Deep Reservoir Characteristics and Effective Reservoir Control Factors in Baiyun Sag of Pearl River Mouth Basin

The Zhuhai Formation and Enping Formation in Baiyun Sag of Pearl River Mouth Basin are important strata for deep oil and gas exploration. Understanding the basic characteristics of deep reservoirs and analyzing the development characteristics and controlling factors of effective reservoirs can provide necessary guidance and support for deep oil and gas exploration to find favorable target layers and target areas. Based on the analyses of petrology and mineralogy, diagenesis, pore development characteristics and sedimentary facies types of deep reservoirs, the basic characteristics of deep reservoirs are clarified. Deep reservoirs are mainly low porosity-low permeability (LL) and tight reservoirs. Compaction is the main reason for the deterioration of deep reservoir, and carbonate cementation and overgrowth of quartz are the main authigenic minerals. Pore types are mainly intergranular dissolved pores and intragranular dissolved pores. Effective reservoirs are mainly LL reservoirs and reservoirs that are better than LL reservoirs. Porosity is generally maintained at about 10%, and permeability varies widely. Sedimentary facies, dissolution and overpressure are the main controlling factors of deep effective reservoir. Medium- and coarse-grained sandstones have better development conditions of primary and secondary pores, higher permeability, weaker porosity reduction by cementation and stronger porosity increase by dissolution. Dissolution is the key constructive diagenesis in deep reservoir, and dissolution pores are the dominate pore type in deep layer. Overpressure conduction is conducive to the activity of acid fluid and the migration of dissolved substances, which is of positive significance to the formation of dissolution pores. Distributary channel and subaqueous distributary channel sandbodies are the main carriers of medium and coarse-grained sandstone and should be the preferred target of deep oil and gas exploration.