All articles in the Oil patch Sub-Sahara Section:

Ngisi Increases The Fortunes OF The Chewa Hub

By Sully Manope
The Ngisi-1 well, located 5km to the North East of the Chewa-1 well offshore Tanzania, has successfully encountered new gas pay zones as well as confirmed the northeastwards extent of reservoirs encountered in the Chewa discovery. “These wells have increased the mean recoverable resource of the Chewa-Pweza-Ngisi hub from 3.7 TCF to 4.5 TCF, in excess of pre-drill expectations, in addition to derisking exploration upside in several nearby targets”, according to Ophir Energy, which holds a 40% interest in Tanzania’s Block 4, with BG as 60% operator.

→   Read the rest of this entry

Starfish Smells Like A Duster

Starfish Smells Like A Duster

By Toyin Akinosho

The latest wildcat well being drilled offshore Ghana is looking like a dud. “Initial interpretation of the wireline logs and MDT data is that no movable hydrocarbons have been encountered in the well, based on the current data”, reports Rialto Energy, the Austrailian minnow which has 12.5% stake in the Offshore Accra Contract Area. “The forward plan is to complete wireline logging operations and evaluation of the well data and block prospectivity. The well will be plugged and abandoned as programmed”.

The Starfish prospect is located offshore Ghana along the prolific offshore West African Margin. The partners regard it as a large, deep-water prospect, “analogous to the Jubilee discovery with unrisked prospective resources estimated to be in the range of half a billion barrels (431 MMbbls (p50); 665 MMbbls (pmean))”.In buying its stake of the Offshore Accra Contract area in December 2012, Rialto Energy was expected to pay around $3 million, and provide a bank guarantee in respect of its participating interest share of the approved work programme and budget for the current exploration period.The company’s share of the well cost is expected to be $10Million. “The prospect was matured following reprocessing of the original 3D seismic data and the acquisition of the new 3D survey in 2011 over the outboard deep water area”, Rialto says in the release. Starfish-1 was drilled to a final total depth of 4,380 metres. Wireline logging operations were undertaken to evaluate the hydrocarbon potential of the primary target. The Offshore Accra Contract Area is operated by Ophir Energy, the Australian independent, with 20%. Other partners include Afex, also with  20%, and Vitol (30%). Tap Oil, which won the lase, holds 17.5%.

The Niger Delta Is Not A Mature Basin-Omatsola

By Toyin Akinosho

People often say that the Niger Delta basin is a mature basin, an oil rich province in the waning days of its productive life. Ebi Omatsola disagrees. “The Niger Delta is a mid- life basin”, he argues.



“Only 2% of Niger Delta wells have reached deeper than 15,000feet(4572metres) Total Depth”, laments Omatsola, managing director of Conoil Producing, the Nigerian independent. “70% of the wells in the basin have not gone deeper than 9,000feet(2743metres) True Vertical Depth. This is something like scratching the surface”, he told a monthly technical meeting of the Petroleum Club recently. Operators, he said, are afraid of taking risks. “Once we run into a shale sequence which gives us a heart attack, we run away”, he told the club, an assembly of owners as well as  ranking managers of E&P companies.

“Rent A Depth”

Omatsola says that policies should be introduced that allow government let companies rent a depth. “If you are holding on to an acreage and you can’t go deeper than a certain depth,can I take it over?”, he asked. “So long as I can show that I can, I should be offered the deeper parts of the acreage below which you can’t go and I should have obligations to drill a certain number of wells, for a certain number of years, before I give it up”. He said that companies “keep talking about incentives”, to do what should ordinarily be in their own interest.

The Niger Delta basin has 37Billion (proven) barrels of oil left, after 47Billion have been produced in 55 years, but oil companies can still find more than twice these remaining reserves, if only they can breach their comfort zones and drill deeper.

There have been several, sporadic attempts in the past. In the mid- 90s, Shell attempted a deep drilling campaign, with mixed results. A decade after, ExxonMobil and TOTAL jointly  spud  a well, targeted to drill deeper than 15,000feet, but pressure problems forced them to stop, even though they were using a High Temperature, High Pressure rig.

As I write this, Agip is drilling a deep well, Ogbainbiri Deep, to appraise and develop the deep sands earlier encountered in Ogbaibiri 2, which is currently producing at shallower depths.

“You’d never find new oil if you’re stuck with the same idea”, warned Omatsola, a 71 year old former Chief Geologist at Shell Nigeria. “Here’s a basin that has productive zones as deep as 20,000feet(6,096 metres),” and that doesn’t have to reach “the lower part of the Agbada(the oil prone, sandy shale sequence in the basin) or Akata, (the massive shale, high pressure sequence)”.

He should know. Conoil, which he heads, is currently drilling a well, Ango-2, with targets at deeper than 16,000feet(4,877 metres) for commercial sized oil pool. Earlier in the year, Conoil flowed 4,000BOPD of light (340 API)oil in two reservoirs inAngo 1Stk 3, in Oil Mining Lease(OML) 59, at depths  between 15,400ft and 15,550ft True Vertical Depth (TVD). “The reservoirs are ponded against a shale ridge”, Omatsola says of the play concept. “It’s the deepest productive zone in the Niger Delta”.

The word ‘productive’ is instructive. Agip has a number of wells that have reached deeper than 16,000feet, but are not producing.

The Ango 1Stk 3 results have provided Omatsola more ammunition to campaign for deep drilling in the Niger Delta. Showing a number of slides of seismic lines indicating strong seismic events at great depths (around 6secs),he told the Petroleum Club that “the Coastal Swamp belt is the most productive depobelt” of the five extensional depobeltsin the onshore terrain of the Niger Delta. “Here, there’s 16,000 feet of untested sequence”.

Omatsola admitted that there were challenges to overcome, in getting everyone on board his “go-deeper” campaign. “You must understand basin modeling”, he told his audience. For this “the geoscientist (geologist and geophysicist) is the key”.

Companies need to embark more on High Resolution deep seismic imaging, which pictures the subsurface clearly as deep as eight (8)seconds (seismic time), equivalent to about 23,000feet(7,010metres)-after time depth conversion.

“We must close the skill gap in the industry and have earth scientists who can tell Schlumberger what they want and not just receive what Schlumberger claims it has to offer”.

And then the industry has to have the tools of deep drilling. “There are only three rigs in the country with the capacity and two of them are owned by Depthsize”. The rigs he was talking about, he said, “must have depth capacity of up to 35,000feet(10,668metres), rated to at least 15,000psi (pounds per square inch) choke/kill/ manifold pressure. Such rigs must be over 3,000HP (Horse Power), absolutely” .

Nigeria, he concluded, must be ready to tap into and develop the potential upside of the Niger Delta Basin.

Kosmos Throws $75Million In The Hole

By Toyin Akinosho
American minnow, Kosmos Energy will record approximately $75 million to exploration expense in its second quarter 2013 results, “associated with the results” of the Sipo-1 well, onshore Cameroon.

The highly publicized wildcat, drilled on the Ndian River Block in the Rio del Rey Basin(a finger of the Niger Delta Basin), failed to encounter commercial reservoirs. Kosmos says, however, the minor “oil and gas shows evidenced during drilling indicated a working petroleum system”.

→   Read the rest of this entry

Sahara Shops For A Rig

Sahara Energy plans to move rig to a location on the Oki field in Nigeria’s Oil Prospecting Lease(OPL) 274 in June 2013. The company is working on contracting a rig. It’s interesting; for a company that has held some of the best prospects in the Niger Delta basin for upwards of seven years and never for once moved on to a drilling location.
Last February, Sahara completed acquisition of 500sq km of three dimensional ( 3D) seismic on the lease, which cost $40Million.

→   Read the rest of this entry

Ivoire 1X Boosts The West African Transform Margin

TOTAL has encountered 28 metres of net oil pay in its Ivoire 1X deep-water exploration well off Cote d’Ivoire.
The well is not tested yet, but the result is a boon for the current geologic thinking focused on the West African Transform Margin(WATM), in which the well is located.
WATM refers to the Cretaceous sequence in the south Atlantic that extends from Nigeria in the east to Sierra Leone in the west. Countries in between include Cote D’Ivoire, Liberia, Benin and Ghana.

→   Read the rest of this entry

Afren Spuds Ogo-1 Offshore Lagos

London listed Afren is on course to spud Ogo-1 in Oil Prospective Lease(OPL) 310 in the Benin Basin, offshore Lagos. OPL 310 is held by Optimum Petroleum, a Nigerian E&P company. Afren is the technical and financing partner. The well is to be drilled by GSF Monitor, a jack up rig owned by Transocean, to a planned depth of 3,536 metres (or 11,600feet). The site is 24km from the Lagos coastline. Logistics will be provided by Lagos Deep Offshore Logistics, LADOL.

→   Read the rest of this entry

Conoil Appraises, Deepens Its Ango Discovery

Majestic Closeup on Location

With 4,000BOPD flowed in two zones in discovery well, operator wants to find out what lies deeper
By Fred Akanni

Conoil, the Nigerian independent, has moved the HTHP swamp barge Majestic to Ango-2, to appraise the deep oil zones it tested in Ango-1 Sidetrack 3 and even probe deeper.

Ango-2 is prognosed to drill to a total depth(TD) of 18,500ft (or 5639metres)  True Vertical Depth (TVD), meaning that it still wants to probe the reservoirs it could not reach, due to tough drilling conditions, in the discovery well.

→   Read the rest of this entry

Anadarko Hits A Duster Offshore Kenya, But..

American independent Anadarko has completed drilling its Kubwa well in the L-07 Block offshore Kenya, which encountered non-commercial oil shows in reservoir-quality sands.

It’s the company’s first probe of Kenya’s deepwater, and the second well in the terrain in eight months. The Mbawa South well  in Block 8, drilled in third quarter 2012 by Apache Corp., another American independent, encountered 53metre net gas pay, making it the first hydrocarbon discovery offshore Kenya,

→   Read the rest of this entry

TOTAL Hits A Fourth Duster In Uganda

TOTAL Hits A Fourth Duster In Uganda

TOTAL continued its streak of dry holes in Uganda’s Lake Albert Basin, with the Ondyek-1 exploration well proving the fourth duster in two months.
Ondyek-1 did not encounter hydrocarbons and has been plugged and abandoned. The well, located 16km North West of the Nigiri-1 oil discovery in the company’s operated EA-1A block to the north of the basin, was the fifth in a drilling campaign designed to test the boundary limits of the TOTAL operated EA-1A Block.
The other dry holes, drilled between December 2012 and February 2013, include: Riwu-1 (tested far northwestern limits), Raa-1 (tested northern extent), and Til-1 (tested far northeastern limits). Ondyek-1 was drilled to a total depth of 1,462 metres.

→   Read the rest of this entry

© 2021 Festac News Press Ltd..