A Prediction Model of Oil Cracked Gas Resources and Its Application in the Gas Pools of Feixianguan Formation in NE Sichuan Basin, SW China

Abstract

The prediction of oil cracked gas resources is necessary and urgent in the gas exploration of these basins at high to over stage in China. A marine crude oil sample was pyrolyzed using sealed gold tubes system in our study. The pyrolysates including gas, liquid, and solid were quantitatively analyzed. Based on the pyrolysis data and kinetic calculation, the yield correlativity among gas, liquid, and solid products was regressed with high correlative coefficients to establish a prediction model suitable for the resource estimation of oil cracked gas. The verification formula for this model was also established on the principle of mass conservation. The affecting factors and the application preconditions of this model were discussed. Finally the model was extrapolated to the prediction of oil cracked gas resources of Feixianguan formation in NE Sichuan basin, SW China. The prediction value of oil cracked resources is about 6.84 × 10 12 m 3 , and generation intensity of oil cracked gas is about 97.5 × 10 8 m 3 /km 2 , and the paleo-oil reserves is about 97 × 10 8 t. The verifying value for this prediction is approximately equal to 1, indicating the model is reliable in the resource estimation of oil cracked gas.

Formation and evolution of solid bitumen during oil cracking

“…4; Zhao et al, 2006). The oil-cracked gas resource for the Feixianguan Formation in NE Sichuan Basin, SW China was estimated based on the Wang et al (2007)'s prediction model (Wang et al, 2011). However, because the distribution of solid bitumen is inhomogeneous, we think that gas generation intensity (GGI, i.e., gas generation amount per unit area) is more helpful for assessing the size of oil-cracked gas reservoirs.…”

“…Due to lack of data, the generation curve of pyrobitumen was speculated for the oil cracking at thermal maturity >2.8% EasyRo, but which is important for investigation of the lower Paleozoic paleo-reservoirs of southern China. Wang et al (2007Wang et al ( , 2011) suggested a prediction model of oil-cracked gas resources based on solid bitumen in reservoir and experimental results.…”