Chocalho

Discovery and Geology

The Chocalho field was one of the discoveries made during the first wildcat drilling program conducted between 1997 and 1999. This program resulted in six discoveries, with Chocalho being one of the four fields announced in 1998, along with Hungo, Kissanje, and Dikanza, which collectively form the Kizomba field complex. The reservoirs in the Chocalho field are from the middle to lower Miocene age and consist of turbidity debris flows deposited along the upper/mid-slope. The structural trap configuration is controlled by early-Aptian salt movement and lateral channel seals.

Development and Infrastructure

The Chocalho field is part of the Kizomba A deepwater development project. Construction on Kizomba A began in 2001, and the project involved the development of both the Hungo and Chocalho oil fields. The infrastructure includes a tension-leg platform (TLP) designed by ABB, using their ETLP (Extended Tension Leg Platform) design, and a Floating, Production, Storage, and Offloading (FPSO) vessel. The FPSO was built by Hyundai Heavy Industries at a cost of over $800 million, and the overall project development involved an estimated investment of $3.2 billion.

Production

The Kizomba A project, which includes the Chocalho field, started producing oil in August 2004 at a rate of more than 130,000 barrels per day (bpd). The target production rate for Kizomba A is 250,000 bpd. By the end of 2008, Kizomba A had 29 production wells and one development well. The project is expected to recover approximately one billion barrels of oil from the Hungo and Chocalho fields.

Technical Details

The TLP for Kizomba A is a dry tree unit that supports multiple wells. The project includes subsea completions tied back to the FPSO. The FPSO has a storage capacity of 2.2 million barrels of oil, although this specific capacity is associated with the Kizomba B project, the Kizomba A FPSO would have similar capabilities. The wells in the Chocalho field, like those in the Hungo field, penetrate multiple high-quality reservoirs, contributing to an oil column exceeding 1,000 meters.

Economic and Operational Impact

The Kizomba A project, including the Chocalho field, is one of the largest and most significant oil projects in Angola. The combined recoverable reserves of the Kizomba field complex, including Chocalho, approach two billion oil-equivalent barrels. The project has contributed substantially to Angola's oil production and has been a key factor in the country's oil industry. The investment in local goods and services, including contracts for in-country fabrication, logistics support, and training of Angolan personnel, has also had a positive impact on the local economy.

Partners and Operators

The Kizomba A project, including the Chocalho field, is operated by Esso Exploration Angola (Block 15) Ltd., an affiliate of ExxonMobil. Other partners in Block 15 include Sonangol, Equinor, and Azule Energy (a joint venture between BP and Eni).