4D Monitoring: Example of 4D Interpretation in Lower flanks systems, Dália - Angola

Abstract

Some field of Lower Congo Basin deep offshore are composed of heterogeneous turbidites channels of Miocene age located in Angola at water depth that range between 700 – 1500 meters. The Dalia field, located in Block 17, is characterized by four main sedimentary complexes, called Upper Main Channel, Lower Main Channel, Lower Flanks and Camelia. This area is characterized by high resolution seismic data (10 m) that is used for fine reservoir characterization and monitoring. After one year and half of production, a first 4D seismic survey was acquired. This 4D seismic monitor bring more accurately interpretation on facies distribution and a better understanding of reservoir communications. The 4D effects seen on Dalia are large since time shifts associated to production were used to interpret 4D signals and upscale them inside the reservoir model.