中-深层优质碎屑岩储层差异发育特征及其主控因素

Differential development characteristics and main controlling factors of high-quality clastic reservoirs in the middle-deep strata： A case study on the Paleogene Yacheng Formation and Neogene Sanya Formation around Ya’nan area， Qiongdongnan Basin

张学成 蔡全升 王伟 胡潜伟 任丽娟 苏奥 胡明毅 胡忠贵 邓庆杰

Xuecheng ZHANG Quansheng CAI Wei WANG Qianwei HU Lijuan REN Ao SU Mingyi HU Zhonggui HU Qingjie DENG

为明确琼东南盆地环崖南地区古近系和新近系中-深层碎屑岩储层差异发育特征及其成因机制，利用大量分析测试资料对崖城凸起、崖城13-1低凸起与崖南低凸起的中-深层碎屑岩储层特征、成储环境以及储层发育主控因素进行了综合研究。结果表明：崖城凸起碎屑岩储层主要为新近系三亚组三角洲砂岩，岩性粒度细，埋深在2 800 ~ 3 100 m，常温、常压环境，颗粒以点-线接触为主，原生孔隙发育，储层平均孔隙度为17.1 %，平均渗透率为494.317 × 10 μm；崖城13-1低凸起主要为古近系崖城组与陵水组三角洲砂岩储层，中-粗砂岩为主，埋深在3 800 ~ 4 100 m，高温常压环境，颗粒多以线-凹凸状接触，溶蚀孔常见，陵水组平均孔隙度为13.5 %，平均渗透率为285.661 × 10 μm，崖城组平均孔隙度为9.2%，平均渗透率为49.158 × 10 μm；崖南低凸起主要为古近系崖城组扇三角洲储层，岩性粒度粗，埋深在4 350 ~ 4 800 m，常温、高压环境，颗粒以点-线接触为主，溶蚀孔发育，见铁质胶结，平均孔隙度为15.8 %，平均渗透率为107.435 × 10 μm。环崖南地区中-深层碎屑岩储层沉积-成岩环境不同，是导致不同构造带储层物性差异发育的主要原因。浅埋藏背景下的弱压实作用是崖城凸起优质储层发育的主控因素，早溶蚀作用以及强压实作用是制约崖城13-1低凸起优质储层发育的破坏性因素，而晚期快速埋藏所形成的超压环境则是崖南低凸起深层优质储层发育的关键。

The study aims to clarify the reservoir development characteristics and genetic mechanisms of different zones. A batch of analytical data is applied to comprehensively investigate the medium-to-deep clastic reservoirs in the Yacheng uplift， Yacheng 13-1 low uplift， and Ya’nan low uplift， focusing on the reservoir characteristics and diagenetic environment， as well as the main factors controlling the high-quality reservoir development. The results indicate that the clastic reservoirs in Yacheng uplift mainly consist of the deltaic sandstone of the Neogene Sanya Formation， characterized by fine grain sizes. These reservoirs exhibit burial depths ranging from 2 800 to 3 100 m， suggesting a normal temperature and pressure （NTP） environment， and with grains predominantly in point-line contacts. Additionally， their primary pores are well-developed， with an average porosity of 17.1 % and an average permeability of 494.317 × 10 μm. The Yacheng 13-1 low uplift primarily exhibits deltaic sandstone reservoirs of the Paleogene Yacheng Formation and the Lingshui Formation. These reservoirs are dominated by medium-to-coarse-grained sandstones， with burial depths ranging from 3 800 m to 4 100 m. They occur in a high-temperature， normal-pressure environment， with grain contacts dominated by linear and concave-convex types， and dissolution pores widely seen within. The Lingshui Formation has an average porosity of 13.5 % and an average permeability of 285.661 × 10 μm， while the Yacheng Formation shows an average porosity of 9.2 % and an average permeability of 49.158 × 10 μm. The Ya’nan low uplift predominantly exhibits fan-delta reservoirs of the Paleogene Yacheng Formation， characterized by coarse-grained sediment and burial depths ranging from 4 350 m to 4 800 m. They occur in a normal-temperature， high-pressure environment， with grain contacts dominated by point and linear types. What’s more， these reservoirs contain well-developed dissolution pores， with ferruginous cements observed， exhibiting an average porosity of 15.8 % and an average permeability of 107.435 × 10 μm. The discrepancies in sedimentary and diagenetic environments are identified as the primary reason for the differential physical properties among medium-to-deep clastic reservoirs across varying structural zones in the circum-Ya’nan area. Specifically， weak compaction under shallow burial conditions is the major factor contributing to the development of high-quality reservoirs in the Yacheng uplift. In contrast， in the Yacheng 13-1 low uplift， early-stage dissolution and strong compaction act as destructive factors that restrict the formation of high-quality reservoirs. Meanwhile， the overpressure environment resulted from rapid burial during the late stage is the key to the growth of deep， high-quality reservoirs in the low uplift.

10.11743/ogg20250312