The heterogeneity

the complexity of source rock distribution

the heterogeneity of source rock types and evolution that resulted from multi-stage tectonic actions in Shiwu Fault-Depression are the main factors causing oil

oil-type gas and coal-gas to distribute regulaly. Multi-series of reservoir-cap assemblages and multi-stage trapping provide multi layer reservoir spaces for oil and gas enrichment; faults and unconformity surfaces are passages for hydrocarbon migration and accumulation. The key period in forming hydrocarbon pools was Nenjiang stage and the key factor was the matching of trap formation period with hydrocarbon generation

migration and accumulation period. According to above mentioned

two hydrocarbon pool forming types

three pool forming ways and six pool forming models have been concluded.