Effects of diagenesis on quality of deep dolomite reservoirs: A case study of the Upper Cambrian Xixiangchi Formation in the eastern Sichuan Basin, China

With the Upper Cambrian Xixiangchi Formation in eastern Sichuan Basin as target, this study investigates various diagenetic events during different stages deep dolomite reservoirs, accompanied by evaluations of their effects on formation and evolution reservoir rock. A series experiments are implemented core outcrop samples, including petrologic analysis, fluid inclusion rare earth minor element investigation, carbon oxygen isotope test. During syngenetic (syndepositional penecontemporaneous) diagenesis stage, dolomitization is closely related to evaporation concentration seepage reflux high-salinity seawater, which facilitates rock development greatly enhancing permeability reservoir. Meanwhile, a small number secondary pores generated sediments subjected episodic atmospheric exposure thus affected meteoric water. early recrystallization transforms part granular into crystalline with or without phantom grain texture. It also alters original rock’s pore structure improves effective primary porosity. Thus, key forming However, compaction, cementation, filling lead loss massive early-formed some pores. mesodiagenesis-late burial karstification, organic matter maturation, most direct control factor reservoirs space formation, its alteration effect process. This research helps better identify impact processes upon rock, it analyze relationships among these processes. The findings provide valuable references for investigating mechanism Basin.