深水海底扇沉积位置特殊、形成过程复杂，关于其储层质量的研究明显滞后于陆上和浅水沉积，研究成果尚不能有效指导储层的油气开发。为此，以西非尼日尔三角洲盆地某深水油田A为例，采用岩心观察描述、测井交会分析、地震属性切片等多种技术手段，深入分析了海底扇储层的质量差异及主控因素。研究结果表明，研究区海底扇储层的原生孔隙发育，所经历的成岩作用较弱，储层质量主要受控于沉积因素。依据岩性和沉积构造，可将研究区储层的岩石相分为交错层理细砂岩、平行层理中-细砂岩、块状中-细砂岩等6类。从微观上看，岩石颗粒的分选和杂基含量分别控制着研究区海底扇储层的储集能力与渗流能力，而粒度中值对于储层孔渗的影响则较小，这一特点导致不同岩石相、不同沉积相之间的储层质量变化表现出特有的规律性；从宏观上看，层序主要通过控制不同沉积相的时空分布以及同类沉积相内部的岩石相组合来影响储层质量的空间差异。%Deep-water submarine fans are characterized by large dimensions ,special deposition positions and complex for-mation processes .Compared with terrestrial and shallow water deposits ,reservoir quality of deep-water submarine fans are poorly studied ,influencing the effective development of this kind of reservoirs .In this paper ,taking deep-water oilfield A in the Niger Delta Basin in West Africa as an example ,reservoir quality differences and controlling factors of submarine fans are researched based on core observations and descriptions ,logging cross plot analyses and seismic attribute slicing . The results show that reservoir spaces of submarine fans are dominated by primary pores and the diagenesis is weak . Therefore,the reservoir quality is mainly controlled by sedimentary factors .According to lithology and sedimentary struc-tures,these reservoirs could be divided into six types of rock facies ,such as cross-laminated fine sandstones ,parallel-la-minated medium to fine sandstones ,massive medium to fine sandstones and so on .Microscopically ,porosity and permea-bility of submarine fan reservoirs are controlled by sorting and matrix content respectively ,but insignificantly influenced by median grain size,resulting in unique variation patterns of reservoir quality of different rock facies or sedimentary facies.Microscopically,spatial quality differences of submarine fan reservoirs are influenced by sequence,which con-trols spatial-temporal distributions of various sedimentary facies and rock facies combinations of the same type of sedi-mentary facies.
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