Control Effects Of Tectonic Evolution Upon Pre-salt Hydrocarbon Accumulation In Santos Basin,Brazil

This article is based on widely collected literature,seismic data and drilling data of oil and gas fields in IHS commercial database,on the basis of plate tectonics theory and analysis of petroliferous basins,this paper explores the control effect of tectnoc evolution of Santos Basin on pre-salt hydrocarbon accumulation by means of synthesis study of petroleum geology and 2D move software,which is helpful to understand pre-salt hydrocarbon accumulation and further widen the field of deep water exploration in Brazil.The results show that :(1)In terms of pre-salt source rocks,the tectonic evolution in syn-rift stage provides good material and environmental conditions for pre-salt source rocks,which is conducive to the generation and preservation of organic matter.The salt rocks formed during the tectonic evolution of transition stage delay the oil generation window at the thick salt rocks.(2)In terms of the pre-salt reservoir,the tectonic evolution in the late stage of syn-rift stage and early stage of transition stage provided a good sedimentary environment for the pre-salt reservoir deposition.The salt rocks formed during the tectonic evolution of transition stage keep good physical conditions for the pre-salt reservoirs.(3)In terms of salt caps,tectonic evolution of transition stage provides good sedimentary conditions,while tectonic evolution of drift stage controls the uneven distribution of salt rocks.(4)In terms of pre-salt traps and hydrocarbon migration,tectonic evolution in of syn-rift stage and transition stage controls the types and distribution of pre-salt traps and paths for pre-salt hydrocarbon migration.(5)In terms of structure control model,fault depressions formed by tectonic evolution of syn-rift stage play the role of source control and trap control,and the effective allocation of sedimentary source rocks,reservoirs,cap rocks and traps in the structural evolution of syn-rift stage and transition stage controls the formation and distribution of hydrocarbon reservoirs.