WEST AFRICA

The Ocean Valiant, used to drill Exxon's second deepest well in West Africa.

OML 102 off Nigeria (upper left) is playing an important role in Nigeria-Equatorial Guinea boundry talks. [64,002 bytes]

Angola: Exxon keeping quiet about Puita

Exxon may not have run into a hitch with its string of successful wells in Block 15, deepwater Angola. Puita-1 was plugged and abandoned on June 23 and the company has maintained a stony silence over it - which is odd.

In the last quarter of the year, Exxon has gleefully announced discovery after discovery. In March, Exxon announced that Kissanje-1, drilled in a water depth of 1,011 meters, had encountered three oil-bearing reservoir intervals, two of which flowed at a combined test rate of about 10,000 b/d of oil.

In April, Marimba-1, drilled in 1,289 meters water depth, encountered an oil bearing reservoir which flowed at an aggregate test rate of about 6,800 b/d of oil. Then in May, Exxon announced it had suspended Hungo-1 (water depth = 1,200 meters, with 175 ft gross of oil column in seven reservoirs.

Puita-1 was drilled in 1,337 meters water depth, making it the second deepest water well that Exxon had drilled in West Africa (after their unfulfilled Bosi-1, drilled in 1,400 meters water depth, offshore Nigeria). The company is steaming ahead. At the time of this report, Exxon had moved the rig Ocean Valiant from Puita-1 to Dikanza-1 location.

Chevron sees bright Angolan future

KU-A01, a development well in Chevron-operated Kuito field in Angola's deepwater Block 14, was suspended early last month after encountering 185 ft of pay in one sand and testing about 1,800 b/d of oil on 28/64-in. choke. Total depth was 1,920 meters. KU-A01 is located in 358 meters water depth. The reservoir is a turbidite sand. Chevron intends to drill three more wells on the structure in the third quarter. The Kuito field is slated to come onstream in the year 2000. It will help to increase Chevron's production in Angola to 600,000 b/d of oil.

In addition to Kuito, Chevron's success with the exploratory well D14-9x (Block 14) seems to have handed the American company another produceable field in deep offshore Cabinda. Named Benguela, D14-9x is reported to have tested high quality oil at encouraging rates. The Kuito field, estimated at 2.5 billion bbl's (STOOIP), is in the same Block, but the company is engaged in active exploratory drilling, testing prospective structures all over the 100 sq km acreage. Such exploratory wells are denoted as D 14-nx, where n is a number. Previously, Chevron has tested 7,500 b/d of oil in D 14-2x; 10,000 b/d of oil in D 14-3x, and over 7,300 b/d of oil in D 14-6x. The current exploratory well drilling is D 14-10x, named Landana.

Gabon: two more discoveries

The rig Glomar Adriatic V, working for Vaalco in Gabon, has been released after Etame-1X (Etame Marine Block) was suspended as an oil well on June 18. The well flowed 3,700 b/d of medium light crude (with no water) on a 36/64-in. choke in a 40 ft thick sand body located in the Gamba formation. The operation was completed in 51 days.
Marathon's East Oroyinvare encountered 163 ft net oil sand in an undisclosed interval after sidetracking the original hole. The well flowed 2,460 b/d of 35° API oil in the Batanga formation. The rig was High Island 1X. East Oroyinvare TD'd at 3,795 ft along hole, which is shallower than the proposed TD by 507 ft.

Nigeria: Elf takes risk in OML 102

Elf is preparing to drill a second well on the Ekanga structure in OML 102, offshore Nigeria, even as talks between Equatorial Guinea and Nigeria are going on. Ekanga-2 will appraise the oil reservoirs encountered in Ekanga-1. The structure is located on the edge of the Nigeria/Equatorial Guinea border, in 130 meters of water. Elf officials are mum about the hydrocarbon count in Ekanga-1, citing it a "political" well. Ekanga-1 was drilled in order to determine whether the Zafiro field, located offshore Equatorial Guinea, extends into Nigerian territory.(Specifically Elf's OML 102).

Zafiro is Equatorial Guinea's sole oil producing field. For several months, Equatorial Guinea authorities spurned appeals from Nigeria for a meeting to determine if Zafiro was a straddle field. It is not known whether the Ekanga-1 reservoirs are the same as those encountered in Zafiro, as Elf has placed a lid on information about Ekanga.

CORRECTION:

A separate article on the Zafiro Flare Stack in the April issue of Offshore contained a number of incorrect statements. The Zafiro Flare Stack installed recently, and shown here, was not a replacement, as suggested by the article, but an augmentation of existing flare capacity. Mobil, the operator, states that production from Zafiro was not halted, as mentioned, for the installation. The buoy flare stack added to the field to augment flaring was fabricated by Ledwood Construction of Wales, England, based on an Aker Maritime design.