Analysis Of Oil And Gas Exploration Potential Of Cretaceous In Julan Basin,Fujian Province

On the base of the predecessors' research,we do the research of the formation characteristics,structural characteristics,and structural evolution by the methods of field exploration,laboratory test,and seismic interpretation.After that,we do the evaluation of the petroleum potential,and do the accurate seismic interpretation,reservoir forming setting.Last,we indicate the hydrocarbon range of profitability,and supply the traps.After the research,the main results and understanding were followings:1)The hydrocarbon original rock in the Bantou Formation was well;the reservoir-cap rock combination was beneficial,there are many hydrocarbons shows,and harvest crude oil in the well testing,so the exploratory potentiality of the work area is better.2)Julan basin was formed in the Cretaceous Period,after two-steps downfaulted movement.The first downfaulted movement was happened in the early stage of the Early Crataceous,and formed the divergent tensional basin,and the hydrocarbon original rock in the Bantou Formation was formed in the late period of the movement,and next period the basin was uplifted and denuded.The second downfaulted movement was happened from the late period of the Early Crataceous to the Late Crataceous,and the half graben-like basin was formed,in part of it,the hydrocarbon original rock in the Bantou Formation was remained.At the last stage of Late Crataceous,the basin was compressed,and the strata was secular exposed and denuded.3)The hydrocarbon original rock in the Bantou Formation became mature only when the buried depth was deeper than the 1600 m.The model of the reservoir forming is the autoclastic self-reserved model,and the reservoir space mainly were pore and fractures in the sand,the capping rock were the mud and the volcaniclastic rock in the Bantou Formation.4)Recently,there are 4 sags in the Julan basin,and controlled by the faults which is Northeast and like North-South strike.In the Number 2 sag,there are wells in it,and harvest crude oil.The oil resource in the Number 3 sag is big,and the research of it was enriched,so the Number 2 and 3 sags are main area for the next exploration.In this research,we found 8 traps,and the Number 6 and 8 traps are better.