Influence of fault transporting pathways for formation of large-medium gas fields with high/middle accumulation efficiency in China

Based on the study of combination types of generation, reservoir and cap rock and types of transporting pathway of gas migration of 53 large-medium gas fields in China, it was thought that the combination types of generation, reservoir and cap rock decided faults being main migration transporting pathways of gas migration. By the study of relation between gas accumulation efficiencys and transporting pathways of these large-medium gas, it was discovered that the large-medium gas fields transported by faults were ones with high or middle gas accumulation efficiency. It resulted from the faults having a strong transporting ability, and there being a good matching relation between transporting period of faults and the main period of gas discharging from source rocks. By comprehensive evaluation parameter of gas transporting ability, the abilities of faults in about 44 large-medium gas fields in China were studied. The results showed that the minimum transporting gas velocity of faults was, generally, more than 0