Discussion on Evaluatoin Principles and Methods of Lithological Trap

s:From the understanding of the theory of oil and gas exploration and the concept of traps,the author proposes a new thinking for geological models of the trap in evaluating system for petroleum exploration.In the models of geological risk for the lithological trap,the appraisal parameters are classified into three levels or aspects i.e.the environmental coefficient for the trap,the probability of the trap being a oil trap,and the reliability of trap identification.As to the calculation of the trap being a oil trap,the traditionally used descriptive factors of trap evaluating (i.e.source rock,reservoir,seal rock,migration,trap,preservation) are divided into three elements.They are ability in capturing oil and gas,storage ability and preservation of the trap which are used to evaluate the probability of hydrocarbon accumulation.