• 责任者：Guo Xiaowen (Key Laboratory of Tectonics and Petroleum Resources ; Ministry of Education ; China University of Geosciences ; Wuhan 430074 ; China) ; He Sheng
• 刊名：Earth Science
• 出版年：2013
• 卷期：38(6)
• 关键词：天然气 ; natural gas ; 烃源岩 ; source rocks
• 页码：p.1263-1270
• 图表：3 illus., 27 refs.
• 分类号：1003
• issnNo：ISSN1000-2383
• isbnNo：CN42-1233/P

     It is very complicated to quantitatively estimate the overpressure caused by natural gas generation in the source rocks with type Ⅲ kerogen firstly due to the small amount of the associated oil to the dominant gas generated and secondly due to the fact that thermal cracking of liquid oil occurs with the increasing depth and temperature. In this paper, a quantitative estimation model for the overpressure change due to natural gas generation is proposed, taking into consideration the episodic natural gas leakage and expulsion, and parameters such as effect of hydrogen index on hydrocarbon generation, thermal cracking of liquid oil to natural gas, the compressibility of kerogen, oil and water, natural gas solution within the water and remaining oil, and so on. In addition, sensitivity analyses of parameters such as carried out. Many parameters can affect overpressure due residual natural gas coefficient, TOC and hydrogen index have been to natural gas generation including source rock porosity, maturity, organic matter abundance, residual natural gas coefficient and so on. Sensitivity analyses indicate that the hydrogen index is the most effective parameter on the pressure change due to natural gas generation in the source rocks and the residual natural gas coefficient has the least effect on the pressure change. Overpressure can be generated when the residual natural gas coefficient is as low to 0. 2, suggesting that the pressure seal in the source rock is not the most important parameter for the overpressure de- velopment caused hy natural gas generation in the source rocks.