Well-logging Evaluation in Shale Gas Reservoir and Its Advances

Shale gas reservoir log evaluation differs from that of conventional gas reservoir because over 90% of shale gas reservoirs need fracturing and the shale bed rock has ultra low porosity and permeability.On the basis of researches on a great number of articles about shale gas reservoir log evaluations since 2008,summarized are geologic characteristics of shale gas reservoir,and introduced are the advances of the reservoir core sample analysis technology and suitable logging methods in shale gas reservoirs.Provided are not only the calculation methods of log total organic carbon(TOC),maturity index(MI) and the parameters of rock mechanical properties,but also the fracture evaluation method.Discussed are existing problems in shale gas reservoir log evaluation,and provided is the feasible developing direction in future research.It is believed that it is necessary to build a full information sample database for shale gas reservoir.