Campos Basin, Brazil, a Model for Producing Atlantic Type Basins
Authors: Guardado L.R. , Wolff B. , Brandlo J.A.S.L. 
Published: October 2008

The Camps Basin covers about 100,000 km2 from the southeastern Brazilian coast to the 3,400 meters ideate. To date, 607 exploratory wells were drilled and about 425,000 km of seismic surveys were acquired and processed.

Early exploration concentrated on Albian and Neocomian carbonates. In 1979, Cretaceous and Eocene turbidities became important targets and until 1984, Eocene and Oligoceneturbidities represented 50% of the targets. In 1984, activities were directed towards deepwater and by 1990, Eocene, Oligocene and Miocene turbidities represented 90% of the targets with a success ratio around 50%. In 1996, Tertiary tepidities accounted for 60%, Upper Cretaceous turbidities for35% and Albian &antes for 5% of the targets drilled in the basin with a success ratio around 60%. To date, Perturb discovered 71 hydrocarbon accumulations (7 are giant fields in deepwater) in the Campos Basin. Tertiary and Cretaceous turbidities represent nearly 90% of the 1,146.1 × lo6 m3 (7,208.0 × lo6 barrels) of the total exploitable reserves (equivalent oil) of the basin. After more than 25 years of exploration, the Camps Basin became the most important Brazilian hydrocarbon province, accounting for nearly 77% of the total exploitable reserves and 69% of the total country's production.

The exploratory success of the Camps Basin after the first discoveries, was influenced by an early and well establishedaccumulation model and by it's own hydrocarbon potential. After 1978, the systematic utilization of 3-D seismic together with an excellent seismic data quality represented a breakthrough in the basin, optimizing the exploratory and development phases by reducing substantially costs and risks. The future of exploration in Campos Basin has already started with planned efforts through ultra-deep waters and deep targets. The exploratory model of the basin guides successfully the exploration in the Santos and Espirito Santo basins and can improve the exploration in other Brazilian, South American and African Atlantic Type Basins.

Introduction

The Camps Basin is located off the southeastern Brazil, along the coast of the Rio de Janeiro State. It covers an area of about 100,000 km2 from the coastline to water depths of3,400m. Only a small portion of the basin (around 500 km2) is located onshore (Fig. 1). To the north, it is separated from the Espirito Santo Basin by the Vitoria High and to the south, it is separated from the Santos Basin by the Cabo Frio High.

The first geological surveys began in the 30140's (Lamego'), with the mapping of the onshore and coastal areas (Fig. 1). Detailed seismic investigations of offshore areas started in 1968, and the first oilfield, the Group field, was discovered in 1974. In 1984185 the first giant deepwateroilfields, Marlirn and Albacora fields, were discovered. Until 1996, 1,14 1 wells (607 exploratory) were drilled, 424,353 km of seismic lines (307,199 km of 3-D) were acquired and 71 fields/ accumulations were discovered Seven of these are giant deepwater fields. By the end of december, 1996, after nearly three decades of exploration, the Campos Basin accounts for approximately 77.2% of the Total Exploitable Reserves and 68.8% of the Brazilian current 0iYga.s production.