Fault belt reservoir controls in Yubei area, Tarim Basin

The structural features and oil and gas sources of the Yubei 1 fault belt in the Yubei area of the Tarim Basin were studied to determine the main geological conditions affecting the production of the Yubei 1 Ordovician oil and gas reservoir (the cumulative oil production before shutdown). Factors considered included the tectonic position of the top surface of the Yingshan Formation (T₇⁵) where wells were located, the development characteristics of fractured and vuggy reservoirs of the Yingshan Formation, the deformation strength of the main and secon-dary thrust faults of the T₇⁵ interface, and the distance between reservoirs and faults. Combined with the main reasons for the failure of the wells YB 3 and YB 3-1 in the Yudong 3 fault belt, east of Yubei, it suggested that the structural location of T₇⁵ and high-quality reservoirs were crucial to hydrocarbon enrichment in the Ordovician in the Yubei area. The structural location was a more important controlling factor for the production of oil and gas reservoirs. However, an excessively high structural location may cause the lack of overlying strata and the exposure of faults in the Late Hercynian, which lead to unfavorable petroleum preservation conditions.