松辽盆地梨树断陷营城组-沙河子组成岩作用及对优质储层的控制

Diagenesis controls on high-quality reservoirs of the Yingcheng-Shahezi formations in the Lishu Fault Depression, Songliao Basin

韩志艳

HAN Zhiyan

中国石化 石油勘探开发研究院 无锡石油地质研究所, 江苏 无锡 214126

Wuxi Research Institute of Petroleum Geology, SINOPEC, Wuxi, Jiangsu 214126, China

通过岩性观察、薄片鉴定和矿物成分统计，对松辽盆地梨树断陷东南斜坡带和北部斜坡带白垩系营城组-沙河子组优质砂岩储层特征进行了研究。该区优质储层主要发育于粒度较粗、可溶性组分含量较高、岩屑含量较低的砂岩中；主要成岩作用有压实、胶结充填、溶蚀和构造裂隙作用等。在成岩过程中，压实作用及胶结作用使储层孔隙大量减少，溶蚀作用则形成大量次生孔隙，构造裂隙是晚期油气的主要运移通道和储集场所。该区储层有“原孔式”、“孔溶式”、“溶孔式”、“裂隙式”、“裂溶式”5种主要的孔隙组合样式，控制优质砂岩储层孔隙发育的成岩作用主要为溶蚀作用及后期构造裂隙作用。砂岩组构好、溶蚀性强、构造裂隙发育、单层厚度大，且与烃源岩邻近的层段及区域，是今后勘探的方向和目标。

Through lithologic observation, thin section identification and mineral composition statistics, the high-quality sandstone reservoirs in the Cretaceous Yingcheng-Shahezi formations in different areas of the Lishu Fault Depression were studied in detail. The results showed that the high-quality reservoirs were mainly developed in sandstones with coarser grain size, higher soluble component content and lower rock debris content. The main diagenesis processes of the target layer in this area include compaction, cementation filling, dissolution and structural fissures. In the process of diagenesis, compaction and cementation reduced the pores of the reservoir, while dissolution formed a large number of secondary pores. The structural fractures were the migration channels and reservoirs of the late oil and gas. It was proposed that the reservoirs in this area have five main pore combinations such as “original pore type”, “porous dissolved type”, “dissolved pore type”, “fractured type” and “cracked type”. The main controlling factors affecting the pore development of high-quality sandstone reservoirs are sandstone fabric, dissolution and later structural fractures. The sandstone has good structure, strong dissolution, tectonic fracture and large single layer thickness, and the interval and area adjacent to the source rock are the direction and target for future exploration.

中国石化科技开发部项目“梨树断陷基岩油气藏勘探潜力及区带评价”（P14041）资助。

https://doi.org/10.11781/sysydz201903398