Chevron Corp. and partners are making progress in developing new crude oil productive capacity off the Angolan enclave of Cabinda.
Chevron unit Cabinda Gulf Oil Co. Ltd. (Cabgoc) has installed a platform jacket in the eastern portion of Kokongo oil field in 343 ft-of water about 40 miles offshore. The platform is expected to go on stream late this year.
Chevron and partners expect to spend about $2.8 billion during the next 5 years to bring Kokongo and several other fields on stream in the Cabgoc operated 2,700 sq mile concession off Cabinda. That is about what the group has spent on exploration and production in the area during the past 25 years.
Chevron declined to disclose production volumes the program is expected to achieve. Currently, the concession's Area A is producing about 300,000 b/d of oil.
State owned Soc. Nacionale de Combustiveis de Angola (Sonangol) owns a 41% equity interest in the concession, with other interests held by Chevron 39.2%, Elf Angola 10%, and Agip Angola Ltd. 9.8%.
NEW DEVELOPMENTS DETAILS
The eastern Kokongo platform is part of the first phase of development of oil fields in Areas B and C of Cabgoc's concession. The eight pile, 16 slot platform, the first of two integrated drilling-production platforms in the field, will be the hub of future development phases in Areas B and C.
Cabgoc in fourth quarter 1993 laid a 38 mile, 24 in. subsea pipeline from Kokongo to transport Area B and C oil and gas to the Malongo onshore terminal. Contract talks are under way on the second and third development phases of Areas B and C, which include Sanha, N'Dola, Nemba, and Lomba fields.
The objective is to begin each additional phase of development about every year. While oil production is the main focus, Cabgoc also is working on commercial gas utilization projects to satisfy government requirements.
Second phase concession development will entail installation of two production platforms and associated pipelines and facilities in Sanha and N'Dola fields. Contracts for the work were awarded in 1993, but the project was delayed by financing issues.
Preliminary development plans for the third phase of concession development, involving Nemba and Lomba fields, have been submitted for government approval.
PRODUCTION UPDATE
Cabgoc maintained full operation throughout 1993 despite continuing civil strife in Angola.
Concession Area A includes 17 significant fields and several more prospects targeted for exploration.
All but one of the Area A fields are producing. The concession reached record production of 324,495 b/d of oil in September 1993, a month before the concession's 25th anniversary. Concession production averaged 295,200 b/d for all of 1993. To date, 363 development wells have been drilled, with 277 currently on stream.
Waterflooding continued at an average injection rate of 376,400 b/d via 32 injectors during 1993, supporting production from Takula and Numbi fields. Liquefied petroleum gas extraction and gas injection in Malongo area fields continued last year, with LPG production averaging 3,620 b/d.
Production from the greater Takula area fields continued to increase in 1993, offsetting natural decline in Malongo area fields. Production from Wamba field in the greater Takula area was curtailed in October 1993 because of a blowout in an infill well. About 18,000 b/d of production was shut in while repairs are under way. Production is to be fully restored this year.
DEVELOPMENT UPDATE
Ten development wells were drilled in Area A fields during 1993, and six wells were worked over.
Three processing platforms in Malongo and Takula fields were revamped and modernized. Cabgoc will continue infill drilling, workovers, and modernizing facilities to maintain Area A output in years to come.
Initial production from N'Sano field, discovered in 1992, was tied back to existing Takula facilities in 1993. A new drilling-production platform to fully develop N'Sano is to be installed by midyear. Plans call for four more N'Sano development wells to be drilled by yearend, and a waterflood program is under study.
South Numbi field, discovered last year, was started up immediately by tying it in to Numbi field facilities. South Numbi will undergo more development drilling this year.
EXPLORATION
One successful wildcat was drilled in 1993 on the Cabgoc group's Area A, finding Southeast Numbi field. Development got under way via an extended reach well drilled from Numbi field facilities. More development drilling is slated for Southeast Numbi this year.
In addition, two wildcats were drilled in Area B during 1993.
A wildcat in Area C found M'Bili field last year, and options for its development are being considered.
The current exploration term for Areas B and C was to have expired at the end of last February with a provision to fulfill all obligations by the end of August 1994. Chevron asked for an extension of the exploration term. Under the existing agreement, two wildcats will be drilled in Areas B and C in 1994. An additional wildcat may be drilled if the extension is granted.
The government granted preliminary award of deepwater Block 14, west of Areas B and C, in 1993. Negotiation of a production sharing agreement between Cabgoc as operator 31%, Sonangol 20%, Total 20%, and Petrogal 9% is under way. An agreement is to be signed this year.
Copyright 1994 Oil & Gas Journal. All Rights Reserved.
