Method for determining hydrocarbon saturation of gas logging

The invention relates to a method for determining the hydrocarbon saturation of gas logging. The method comprises the following steps of: acquiring and recording values of non-hydrocarbon components such as gas logging total hydrocarbon and methane through logging devices such as a gas logging apparatus and a comprehensive logging instrument; reading the maximum abnormity value Ct of the total hydrocarbon or methane in an oil-gas abnormity display interval; preferably selecting a gas logging background value Cb of an oil-gas display layer; selecting the hydrocarbon saturation index n of regional gas logging; and working out the hydrocarbon saturation Sh of a specific oil-gas display interval, and outputting a computed result. The method is low in cost, is easy, convenient and accurate, and has a wide application range. According to the method, the hydrocarbon saturations of gas logging oil-gas display layers in 3,700 intervals of more than 610 wells are explained and computed in the Jianghan Basin, the Western Hubei-Eastern Chongqing Area, the Tsaidam Basin, the Ordos Basin and the Tarim Basin, errors do not surpass 15 percent generally in comparison to the logging measurement computed result, the hydrocarbon saturation accuracy is increased by over one time in comparison to the hydrocarbon saturation accuracy determined with a thermal vacuum distillation all-dehydration technology, and the rapid explanation requirements of logging oil-gas display fields can be well met.