Diagenesis and controlling factors of tight sandstone reservoirs: A case study of the lower member of Silurian Kepingtage Formation in Shuntuoguole area, Tarim Basin

Tight sandstone reservoirs in the lower member of Silurian Kepingtage Formation in Shuntuoguole area of the Tarim Basin were studied through core observation, thin section identification, scanning electron microscopy, X-ray diffraction and fluid inclusion homogenization temperatures. They mainly consist of fine-grained debris sandstones with poor physical properties. Five types of diagenetic effects occurred, including compaction, cementation, erosion, metasomatism, and tectonic fracturing. Compaction made the reservoir physical properties become poorer, while erosion improved them. They are mainly within the middle diagenesis stage A, and locally in the middle diagenesis stage B. Diagenetic effects were dominated by many factors. Sedimentary environment and debris predominated the degree of compaction and erosion, burial history and temperature macroscopically controlled diagenesis development, while hydrocarbon charging microscopically reduced the cementation rate and enhanced the erosion of soluble components.