Phase characteristics and geological significance of coal-generated hydrocarbon: Take the Minhe Basin as an example. Issue 4 (July 2019)

• Record Type: Journal Article
• Authors: Deliang, Fu; Shixin, Zhou; Guosheng, Xu; Tao, Tian; Yu, Ma
• Is Part Of: Energy exploration & exploitation. Volume 37:Issue 4(2019)
• Page Start: 1306
• Page End: 1319
• Publication Date: 2019-07
• Subjects: Pyrolysis experiment -- phase behavior -- coal -- kinetic simulation -- gas generation -- Minhe Basin; Power resources -- Periodicals; 333.79
• DOI: 10.1177/0144598718823956
• Languages: English
• ISSNs: 0144-5987

Abstract

The phase characteristics of petroleum fluids are directly related to the hydrocarbon accumulation, and through exploration and development, the evolution process of hydrocarbon generation from coal is found to be complex, with variable fluid phases. To explore the relationship between the hydrocarbon generation process and fluid phase evolution of the coal, we derive the kinetic parameters for the gaseous hydrocarbons and methane generated from a series of closed-system laboratory pyrolysis tests of a Jurassic coal from the Minhe Basin and established a phase evolution diagram of the coal-generated fluids and the corresponding geological conditions. The study shows that with a fixed frequency factor of 1.0 × 10 14 /s, the mean values of activation energies of C1 and C1–5 are 64.55 kCal/mol and 63.93 kCal/mol, respectively. The phase of the coal-generated hydrocarbon fluids produced under geological conditions shows that an undersaturated oil phase or an oil–gas phases is possible when Easy%Ro <1.08, any phase is possible when Easy%Ro is between 1.08 and 1.36, an undersaturated gas phase or an oil–gas phases is possible when Easy%Ro is between 1.36 and 2.05, and a gas phase is possible when Easy%Ro > 2.05. The hydrocarbon generated from the Jurassic coal of the Minhe Basin started as an oil phase in the Early Cretaceous, and the fluid phase may have changed from oil phase to oil–gas phases in the late Early Cretaceous, The fluid changed to gas phase after the Miocene. Additionally, the source rock is still in the stage of gas generation currently.