Structural characterization and hydrocarbon prediction for the SB5M strike-slip fault zone in the Shuntuo Low Uplift, Tarim Basin

Newly discovered superdeep marine carbonate reservoirs with burial depths of more than 7000 m are found in the Shuntuo Low Uplift, Tarim Basin, China. Previous exploration experience indicates that strike-slip faults in these deposits played a key role in reservoir formation and hydrocarbon accumulation. This paper describes the structural and hydrocarbon characteristics of the SB5M strike-slip fault zone in the Shuntuo Low Uplift based on the study of high-quality 3-D seismic volumes and drilling data. The SB5M fault is a repeatedly reactivated strike-slip vertical fault zone. In the Paleozoic strata, the SB5M strike-slip fault zone is composed of sub-vertical strike-slip faults in the deep layer, a graben structure in the middle layer, and enechelon normal faults in the shallow layer. The deep, middle and shallow faults developed sequentially at different times and formed as a result of three-stage evolution: the Middle Caledonian, Late Caledonian, and Middle-Late Hercynian. Fracture networks formed by repeated fault activity provided pathways for karst flow and hydrocarbons, which are conducive to the formation of fracture-cavity reservoirs. Due to the fault damage zone-fault core transition and the complex structural features, the reservoirs controlled by the SB5M strike-slip fault zone feature strong heterogeneity. The data sets presented and evolution models established in this paper provide important data for the exploration and development of the SB5M strike-slip fault zone and represent references for structural analysis and hydrocarbon exploration of strike-slip fault zones in the Tarim Basin and elsewhere.