Petroleum System Analysis And Exploration Potential For The Pre-salt Sequences In The Campos Basin,Brazil

Using the method of petroleum system analysis combined with the anatomy of typical oil and gas fields and physical simulation experiment,this study has revealed the oil and gas prospectivity of the Campos basin.After all the work that had been done,the results indicate that:(1)There is only one petroleum system in the pre-salt formations of the Campos basin which is named as the Logoa Feia-Logoa Feia petroleum system.The lacustrine shale comprises the source rocks of this system and the hydrocarbons that originated from the Logoa Feia lacustrine shales were trapped in the coquinas limestone reservoirs.The trap styles in this system are dominated by stratigraphic and combination traps.(2)Salt is the most significant factor that controls the accumulation of the oil and gas in this basin.Experiments have shown that the behavior pattern of the salt in Campos basin is the slide model.Affected by the gravity of the sediments and the salt itself the deposits will move along the slope causing the deformation of the salt.(3)Using the discovery sequence method,the number of the undiscovered oil and gas field is estimated to be 57 and the undiscovered recoverable resources is about 5.5Bboe.(4)The scale of the oil and gas accumulation depends on the quality of the source rock.The high quality source rock is the fundamental control for hydrocarbon accumulation and the syn-rift horst will affect the location of the oil and gas accumulations.The high-quality lacustrine limestone is the most prospective area that can trap abundant oil and gas.