Differences and controlling factors of composite hydrocarbon accumulations in the Tazhong uplift, Tarim Basin, NW China

JIANG Tongwen,HAN Jianfa,WU Guanghui,YU Hongfeng,SU Zhou,XIONG Chang,CHEN Jun,ZHANG Huifang

Table 2 Phase state data of fluids in the fault-controlled composite oil and gas enrichment area of the Tazhong uplift.

Oil & gas field/fault zone Horizon Formation pressure/ MPa Formation temperature/°C Saturation pressure/ MPa Crude oil density/ (g?cm-3) Gas-oil ratio/ (m3?m-3) Methane content/ % Dew point pressure/ MPa Critical pressure/ MPa Critical evaporation pressure/MPa Critical temperature/°C Critical evaporation temperature/°C Oil and gas reservoir type Tazhong 4 Carboniferous 33.02 98.0 6.17 0.8280 200 7.78 11.35 598.1 659.7 Black oil Tazhong 16 44.18 110.1 7.07 0.7936 25 3.80 7.44 454.8 456.2 Tazhong 11 Silurian 45.43 113.1 18.55 0.7670 74 7.21 20.18 487.5 491.9 Black oil Tazhong 12 50.80 115.3 3.28 0.9555 5 1.98 3.29 507.6 507.7 Heavy oil Tazhong 62 Ordovician Lianglitag Formation 55.64 130.2 55.64 0.8110 3 245 91.92 55.64 29.59 59.20 -99.2 315.3 Condensate Tazhong 82 63.96 137.3 61.43 0.7972 2 316 83.09 61.43 40.12 62.71 -89.8 407.2 Zhonggu 43 Ordovician Yingshan Formation 63.33 124.9 56.99 0.7620 1 018 79.91 56.99 48.74 58.89 -37.4 346.9 Condensate Zhonggu 8 66.11 148.0 44.61 0.7878 951 78.81 44.61 30.24 45.61 -43.2 345.6 Zhonggu 15 Ordovician Yijinafang Formation 69.43 133.7 33.42 0.6001 305 22.18 33.44 337.6 412.0 Unsaturated oil