During the middle to late 1980s, Exxon Exploration Company embarked on a series of global integrated regional geologic studies, culminating in the discovery of several giant oil and gas fields. Aggressive acreage-capture strategies were initiated based on these studies, with early participation in opening tender rounds in the identified high-potential basins. From a position of having no acreage in the Congo Basin, offshore Angola, ExxonMobil rapidly became the largest deep-water acreage holder in Angola. Block 15 was included in the first tranches of deep-water acreage offered by the Angolan government and was awarded to a contractor group led by ExxonMobil's subsidiary, Esso Exploration Angola (Block 15) as operator.

After early two-dimensional seismic acquisition to high-grade areas of interest, 4000 km² of high-quality, three-dimensional seismic data was acquired for prospect mapping. Wildcat drilling during 1997–2002 resulted in 13 discoveries in water depths ranging from 500 to 1400 m. Recoverable hydrocarbons are estimated to be in excess of 3.5 billion BOE, with significant undiscovered potential remaining on the block. Oil gravities range from 24 to 35 API.

Four of the discoveries (Hungo, Chocalho, Kissanje, and Dikanza) make up the giant Kizomba field complex, with recoverable hydrocarbons of more than 2.0 billion bbl. Each of the discovery wells penetrated multiple high-quality, deep-water channel sandstones with oil-water contacts controlled by a combination of structural spill, fault leak, and top seal failure because of buoyancy effects of hydrocarbon columns approaching 1000 m. Reservoirs range from 500 to 1900 m below mud line. The hydrocarbons occur in combination structural-stratigraphic traps. The large north-trending structures are a result of Oligocene–Miocene extension with associated movement of Aptian salt, culminating in middle Miocene to recent diapirism. Lateral seal is provided by stratigraphic pinch-out and onlap of reservoir facies at the margins of the large west-trending channel complexes. Top seal is formed by overlying channel abandonment facies or by prograding slope shales. Reservoirs are early to middle Miocene in age and are dominantly turbidites with associated debris flows deposited in channel complexes on the middle to lower slope. Reservoir properties are excellent.

Kizomba will be ExxonMobil's first operated Angolan oil development, with production start-up expected during 2004. The development will take place in approximately 1200 m of water. The first phase, Kizomba A, will involve about half of the Kizomba reserves (approximately 1 billion BOE). The primary drive mechanism for these relatively shallow reservoirs will be waterflood with injection of associated gas early in project life. Production will be via dry trees from a tension-leg platform with associated subsea facilities for injection wells. Oil will be produced to a floating production storage and offloading (FPSO) vessel, which will offload to tankers via a nearby catenary anchor-leg mooring buoy. The second phase, Kizomba B, will be developed by a similar combination of subsea and surface wellhead platform facilities tied to a second FPSO.

The successful discovery of this giant field is a result of the application of leading-edge technologies systematically integrated into regional exploration experiences and strategies. The future will involve continued emphasis on innovative development technologies to maximize production in this challenging deep offshore environment.