Abstract:

The formation and evolution of Lanliao fault belt in Dongpu Depression may be divided into two periods and five stages such as Mesozoic and Cenozoic Periods,and compression,iniital fracture,strong fracture,shrinkage and after vibration stages.Hydrocarbon trap types in Lanliao fault belt are various.According to oil and gas geological feature,the location of traps,the screening condition and the occurrence,the trap types could be divided into eight kinds,i.e.the nose structure,half-anticline,the upwarping lithologic trap,buried-hill trap,stratigraphic unconformity trap,the reef trap,the paleochannellithological trap and the nappe structural trap.Rich oil and gas source,favourable hydrocarbon migration conditions,the multi-passage,the subaqueous fan sandbodies and structure-controlling are the major factors of hydrocarbon accumulation.

Key words: structural evolution, trap type, controlling factor for hydrocarbon, Lanliao fault belt, Dongpu Depression