珠江口盆地陆丰凹陷A油田储层质量差异及低渗储层主控因素

南海珠江口盆地自投入油气勘探开发以来，关于该区新近系海相储层的研究已日趋成熟，但是由于深层的勘探开发起步较晚，加之海上井数的限制，深层储层质量的研究相对薄弱，尚不能有效的指导油气田勘探与开发。为此，以南海珠江口盆地陆丰凹陷A油田为例，从微观孔隙结构和宏观物性对比了新近系珠江组滨岸储层和古近系文昌组辫状河三角洲储层的质量差异性，并分析了文昌组低孔、低渗储层的主控因素，以期指导该类油田开发方案的设计。研究表明：A油田储层质量宏观上受控于构造沉积作用，沉积作用一定程度上控制了后期的成岩作用，是造成珠江组与文昌组储层质量差异的主要原因；文昌组低孔低渗储层的主要控制因素为成岩作用，成岩作用减弱了原始沉积组构对储层质量的控制作用，使储层物性变差，并对后期油田开发造成影响。

Reservoir quality differences and major factors controlling low-permeability reservoirs of Oilfield A in the Lufeng Sag,Pearl River Mouth Basin

Since the initiation of oil and gas exploration and development in the Pearl River Mouth Basin,South China Sea,understanding of the Neogene marine reservoirs has been deepening.However,understanding of the deep reservoir quality is still weak due to the late initiation of deep exploration and development and the sparseness of offshore wells,thus is inefficient to guide exploration and development.By taking Oilfield A of Lufeng sag as an example,we compared the reservoir quality between the braided river delta facies in the Paleogene Wenchang Formation and the shorefacies in the Neogene Zhujiang Formation in respects of microscopic pore structure and macroscopic physical properties.In addition,we also analyzed the main controlling factors of the low porosity and permeability reservoirs in the Wenchang Formation,so as to guide development planning of this kind of oilfield.Results show that the reservoir quality of Oilfield A is generally controlled by the tectonic sedimentation,the sedimentation in turn controls the late diagenesis to some extent,resulting in the reservoir quality difference between the Zhujiang Formation and Wenchang Formation.Diagenesis is the major controlling factor of the low porosity and permeability reservoirs in the Wenchang Formation.Diagenesis weakens the control of original sedimentary fabric on reservoir quality.It lowers porosity and permeability of the reservoirs and influences the later development of the oilfield.