A Quantitative Evaluation Method for the Natural Gas Hydrate Reservoir Parameters in the Shenhu Area,South China Sea
Marine gas hydrate exists in the unconsolidated argillaceous silt and silty mud formations in a solid state.It is completely different from the occurrence of conventional oil and gas reservoirs,which are consolida-ted sandstone formations.Therefore,the logging evaluation of hydrate reservoirs is more challenging than the conventional ones.Since 2007,four hydrate drillings have been carried out in the Shenhu area of South China Sea.Abundant geophysical and core data have been obtained and it has been confirmed that there is a huge po-tential for natural gas hydrate resources in this area.In this study,starting from the research and analysis of conventional logging,special logging data,and core data in Shenhu,we summarized the logging response char-acteristics of hydrate formation.The core data were used to calibrate logging.At the end,the calculation model of reservoir lithology,physical properties,and hydrate saturation is established.Consequently,a set of quanti-tative evaluation system for natural gas hydrate reservoir parameters in the Shenhu area is proposed.The pro-posed method in this study was used to evaluate the wells comprehensively.The average porosity of hydrate for-mation is 49.91％,and the average hydrate saturation is 29.75％.The pore structure is mainly small pores and the permeability is poor.The evaluation results are consistent with the core experimental results with a coinci-dence rate of 85％.The research results provide a new reference for the evaluation of hydrate resources and ac-cumulation in the Shenhu area.
gas hydratelogging response characteristicsreservoir parameter calculationquantitative evalua-tion method
国家科技期刊平台
NSTL
万方数据
维普
