3-D Modeling for Hydrocarbon Exploration in Deep Water Angola

Lino S. Buambua
Exploration DEX, Sonangol, Luanda, Angola

Angola’s deep water play is the most active hydrocarbon exploration region in West Africa; currently, Angola produces more than 1.8 million bopd of which some 70% is from the deep water reservoirs of the prolific Lower Congo Basin. Several oil and gas discoveries are known: Girassol, Dália, Rosa, Hungo, Chocalho, Kissanje, Dikanza (Kizomba), Marimba, Benguela-Belize, Plutónio, Saturno, Palas, Juno, Astraea, Miranda, Urano, Louro etc. are some of the discoveries. A number of these discoveries are in production and are expected to have a substantial recoverable resource.

The identified reservoirs, in Angola, are deep water turbidite systems of channels and sheet sands. These are of Miocene and Oligocene age. The reservoir closure is against salt, which describes a structural and/or stratigraphic trap. 3D high resolution models and seismic reservoir characterization techniques are invariably employed in these fields in the early stage of exploitation.
A robust 3D geological model has been built for deep water exploration, that integrates modern seismic data, well data, geological interpretation and petrophysical relationships. Qualitative and quantitative model realizations describe probabilistic trends in reservoir geometry, heterogeneity, facies proportions, porosity and permeability in three dimensions.

The aim of this paper is to describe the generic construction of a high-resolution 3D geological model that has been used to understand the impact of geological uncertainties in deep water exploration, as well as define additional opportunities for oil recovery in the challenging Angolan deep water salt province. Modern interpretations allied with software technology designed for deep water reservoir description, characterization and modeling enables the oil industry to reduce the uncertainties regarding their exploration and production.

AAPG International Conference and Exhibition, Cape Town, South Africa 2008 © AAPG Search and Discovery