Oil & Gas Geology ›› 2009, Vol. 30 ›› Issue (1): 85-89.doi: 10.11743/ogg20090112

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Origin of natural gas in Mingfeng area,the Jiyang Depression

Hu Xiaoqing1, Jin Qiang2, Wang Xiuhong3, Lin Lamei2, Wang Li2, Wang Juan2, Wang Tingting4   

  1. 1. CNOOC Research Center, Beijing 100027, China;
    2. China University of Petroleum, Dongying, Shandong 257061, China;
    3. Research Institute of Geological Sciences, SINOPEC Shengli Oilfield Company, Dongying, Shandong 257100, China;
    4. CNPC Liaohe Petroleum Exploration Bureau, Panjing, Liaoning 124010, China
  • Received:2008-09-10 Online:2009-02-25 Published:2012-01-16

Abstract:

It is controversial about the origin of the natural gas in Minfeng area.A set of indexes for differentiating kerogen-pyrolysis gas and oil-cracked gas is presented based on geologic analysis and thermal simulation experiments on source rocks and crude oil samples from the Es4.In mature phase,the kerogen-pyrolysis gas features in rapid generation of methane and low contents of cyclane and benzene.While in high mature phase,both kerogen-pyrogenic gas and oil-cracked gas are characterized by high contents of cyclane and benzene.The condensate oil and natural gas in Mingfeng area show a larger scope of ln(C1/C2) ranging from 2 to 6 than that of ln(C2/C3) varing from 1 to 1.5 and have relatively high contents of cyclane,isoalkane and aromatic hydrocarbon,revealing the characteristics of kerogen-pyrolysis gas in high mature phase.Therefore,it is believed that the natural gas in Minfeng area is of kerogen-pyrolysis gas.

Key words: kerogen-pyrolysis gas, oil-cracked gas, light hydrocarbon, thermal simulation experiment, Jiyang Depression

CLC Number: