Abstract：Under the same gas source condition,undercompacted mud formation has higher gas concentration than normally-compacted one does(the higher part is called abnormal gas concentration).Abnormal gas concentration is correlative with abnormal pore fluid pressure,and there is also certain correlation between abnormal pore fluid pressure and acoustic transit time. Such correlation has been already described quantitatively. In terms of this correlativity, one can derive abnormal gas concentration in barrier layer from acoustic transit time data. This method was used to estimate the abnormal gas concentration of Qingshankou mud barrier in north Songliao basin. The estimation result favours both quantitative evaluation of hydrocarbon sealing ability of Qingshankou mud barrier and planar evaluation of hydrocarbon sealing ability.
付广, 张发强. 利用声波时差资料求取烃盖层异常含气浓度的方法及其应用[J]. 石油地球物理勘探, 1998, 33(4): 511-518.
Fu Guang, Zhang Faqiang. A method fog deriving abnormal gas concentration in barrier from acoustic transit time data，and its application. OGP, 1998, 33(4): 511-518.
