Strike-slip faults and their controls on hydrocarbon reservoirs in the Yuecan block of the Northern Tarim Uplift, Tarim Basin

We studied the production performance of about 30 wells in the Yuecan block of the Northern Tarim Uplift in the Tarim Basin, and considered the controls of the X-shaped strike-slip faults in the study area on the Ordovician fractured and vuggy system reservoirs, combined with core sample observations and testing. The strike-slip faults were active during multiple stages, and formed a large number of high-angle tectonic fractures, which developed a large fractured and vuggy system during the following thermal evolution. Oil and gas migrated upwards along the main strike-slip faults, then redistributed along secondary faults, and finally determined the hydrocarbon properties and charging extentin the study area. Reservoirs with a high charging degree and excellent crude oil properties were found in the main strike-slip faults, and the wells showed a good production performance. On the contrary, the secondary strike-slip faults had a low charge and poor crude oil properties, and the wells showed poorer production performance. In addition, the direction of strike-slip faults, the relative position of fault walls, and the distance to faults also played important roles in controlling hydrocarbon enrichment.Results showed that hydrocarbon was most enriched in the upper wall of the NE-oriented strike-slip faults.