Structural Characteristics Of Offshore Basins And Their Influence On Reservoirs In Cuba’s Exclusive Economic Zone

Cuba’s Exclusive Economic Zone(CEEZ)is located in the oil and gas bearing zone in the north of Cuba,and the oil and gas exploration and development in northern Cuba are mainly focused on onshore and shallow water areas.Based on the processing and interpretation of the newly collected 2D seismic data,a more comprehensive and high-quality offshore seismic data of Cuba is obtained in this article.Using the new seismic data,this article puts forward a new understanding of the structural style of the offshore basin,analyzes the structural evolution process of the study area,and summarizes the influence of the structure on the oil and gas reservoir.The study shows that the sedimentary characteristics of stratigraphic strata in this area are controlled by the tectonic movement of the Caribbean plate,and the stratigraphic distribution gradually changes from west to East.Since the Late Triassic,the region has experienced rift basin development stage,continental drift stage,orogenic stage,and post orogenic strike slip stage.According to the structural evolution characteristics and structural types,the structural units of the CEEZ are divided into thrust nappe belt,foreland basin,Florida platform,Yucatan platform,central basin and Sigepipe basin.Combine new seismic interpretation result and well data,this article analyzes the spatial allocation relationship of four sets of main source rocks,middle lower Jurassic mudstone,which is the main source rock,deep-water carbonate rock and mudstone,which are mainly distributed in Upper Jurassic,Upper Cretaceous carbonate rock and Paleocene mudstone.Three sets of main reservoirs,Early Jurassic rift clastic reservoir,Cretaceous carbonate reservoir and Paleogene carbonate fractured reservoir.In addition,by studying the stratigraphic deposition since Eocene,it is found that the caprock distribution in this area is local.Structural reservoir is one of the commonly developed reservoir types in Cuba’s exclusive economic zone.It has been found in various structural units,and it is also the main oil and gas reservoir type confirmed by the discovered oil and gas fields.In addition,stratigraphic reservoirs and lithologic reservoirs are also the key types of reservoirs in this area.