西南石油大学学报(自然科学版)

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Quantitative Evaluation of Carbon Dioxide Content in Natural#br# Gas Reservoir with Logging Data

HE Shenglin1, ZHAO Jun2*, ZHOU Jiaxiong1, ZHANG Hairong1, WANG Di2   

  1. 1. Research Institute of Zhanjiang Company,CNOOC,Zhanjiang,Guangdong 524057,China
    2. School of Geoscience and Technology,Southwest Petroleum University,Chengdu,Sichuan 610500,China
  • Online:2016-08-01 Published:2016-08-01

Abstract:

When carbon dioxide exists in gas zone,pore fluid composition and logging response are getting more complex
because of the presence of hydrocarbon gas,non-hydrocarbon gas and irreducible water. The extra conductivity caused by the
dissolution of carbon dioxide is absolutely weak and no apparent regulation exists in it,which makes qualitative identification
and quantitative calculation of carbon dioxide very difficult. According to the different influence of methane and carbon dioxide
on thermal neutron moderation and diffusion,this paper builds the carbon dioxide quantitative calculation model with porosity
logging methods based on neutron′s long and short spacing counting rates. Then,in consideration of the logging response
features of methane and carbon dioxide with reservoir at high temperature and high pressure,and by using porosity and saturation
data,we adopted the optimization method based on rock′s physical volume model and calculated the content of each fluid
composition. The effect is proven to be reliable through comparison between the interpretation results and testing conclusion.

Key words: carbon dioxide;neutron&prime, s long and short spacing counting rate;optimization method;physical volume model;
Archie equation

CLC Number: