Page 10 - AfrOil Week 47 2019

AfrOil
NEWS IN BRIEF
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UPSTREAM
Global Petroleum offers
new resources estimate for
PEL 94 offshore Namibia
Global Petroleum has announced its estimate of prospective resources for PEL0094 (Block 2011A), offshore Namibia. Global holds a work- ing interest of 85% and is operator of the licence.
A total of 964mn barrels of unrisked gross technical prospective resources (Best Estimate) has been estimated in PEL0094. Of particular note, the Albian carbonate reservoir at Wel- witschia Deep has been estimated to have Best Estimate unrisked gross prospective resources of 772mn barrels of oil with a probability of success of 15%.
The prospective resources are based on 2D seismic data and geological information, including analogues, to which Global has access at the current time. Global is confident that more prospects and leads will be identified once it has licensed and interpreted the remainder of the existing seismic data in PEL0094, both 2D and 3D, as well as tying in some of the analogous reservoirs in offset wells. In particular, the plays in the Upper Cretaceous/Paleocene sandstones and Albian carbonates are partially covered by the existing 3D seismic data. Further work may increase the geological chance of success of the prospective resources. Updated prospec- tive resources and their associated geological chances of success will be calculated once work has been completed.
Peter Hill, Global Petroleum’s CEO, com- mented: “Our technical work to date on PEL0094 confirms that the acreage is highly prospective. We are delighted that our review of the data so far has confirmed the high level of prospectivity of PEL0094 generally, and of the Welwitschia Deep prospect in particular, which contains unrisked Best Estimate prospective resources of nearly 800mn barrels. Specifically, our work suggests that the Welwitschia-1A well - drilled in 2014 by previous licensees - was abandoned before reaching the underlying Welwitschia Deep pros- pect. Moreover, the 2014 well was drilled to the west of the newly identified Marula lead, located in the Upper Cretaceous which was the primary target of Welwitschia-1A. These factors, together with the scale of the prospective resource num- bers which we have released today, demonstrate that both Welwitschia Deep and Marula are very attractive targets.”
The Welwitschia Deep prospect is a fault and dip-closed structural trap, as are the Gemsbok, Lion and Dik Dik prospects in the company’s PEL0029 licence, which is immediately adjacent to PEL0094 to the west. The Repsol operated
Welwitschia-1A well, which was drilled in the western part of Block 2011A in 2014, primarily targeted Upper Cretaceous sands on the crest of a large structure but did not encounter a reser- voir. However, Global has now quantified part of the significant prospectivity in the deeper Albian Carbonates (Welwitschia Deep), which Welwitschia-1A did not reach.
The Marula lead is a stratigraphic trap, where the Upper Cretaceous, deep water sandstones pinch out to the west onto the Welwitschia struc- ture. The reservoir is the same age as the target of the Welwitschia-1A well where the sands were found to be absent, thus providing strong evi- dence of an excellent lateral seal 4 km to the west of the Marula lead.
The reservoir for Marula is proven at the 2012/13-1 well 100 km to the south-east, where light and heavy oil was extracted from well samples.
Global Petroleum, November 26 2019
Total builds on Brulpadda
success to herald new era
for South Africa
One of the most important discoveries of the year took place 175 km off the southern coast of South Africa, where Total has made a gas con- densate discovery on the Brulpadda prospects, located on Block 11B/12B in the Outeniqua Basin. The exploration well encountered 57 metres of net gas condensate play in Lower Cre- taceous reservoirs. Following the success of the main objective, the well was deepened to a final depth of 3,633 metres and has also been success- ful in the Brulpadda-deep prospect.
Speaking at Africa Oil Week, Dr Enzo Insa- laco, vice president for exploration in Africa at Total, explained that South Africa has become an interesting area for exploration. “When you look at the fundamentals, you can see a scenario where there are a number of significant, rela- tively underexplored basins and many of the play fundamentals are present in these places,” he said. “We see that there’s a lot of scope for explo- ration and significant potential.”
That interest has been illustrated by the recent activity by the industry, which has seen a signifi- cant amount of seismic capture and blocks being taken in Namibia and South Africa. “Much of that activity is early-stage, so 2D or 3D,” Insalaco added. “What we will see in the next few years is an uptick in reservoir drilling and exploration. We have a strong position in the oil basin, so we have a couple of blocks in the Orange Basin and in South Africa the 11B/12B block where this discovery was made.”
For Total, Brulpadda was certainly a high impact well for opening up what they believe
is a significant petroleum basin. “It was a very bold technical well,” Insalaco continued. “Many people may not realise that the well was actu- ally drilled on 2D. It is a deep offshore well, so drilling on 2D was a very bold move. But given our understanding of the basin and the innova- tions we did on the operations, this well could be drilled safely and successfully on 2D.”
“As we know, it was an operational success just as much as a technical success; we drilled the well within budget [and] within time. And in terms of NPT, we have about 3% of NPT and 3% waiting on weather. If you consider the condi- tions, that is fantastic operational performance. We drilled the well to the main reservoir log and then we went down to a deeper reservoir.”
“We did extensive logging records, took samples of fluid, reservoir and source rock. It was a fantastic result in terms of operational performance and data acquisition. It is a gas and condensate and oil discovery, both traces were found. The reservoirs were well-developed with good fluid and reservoir properties. You could not really wish for more information from an exploration well. That data acquisition has really put us in a great position going forward to be able to accelerate the next level and the evaluation.”
The fact that Total drilled the prospect on basic 2D seismic data meant that they needed to hit the ground running in the discovery sce- nario. They planned for success and were ready to shoot the 3D campaign as soon as they were comfortable that the well was successful and there was going to be potential on the basin. “We were ready for 3D. We were already negotiating contracts on the way,” Insalaco added. “When you look at the milestones on the well, you can see that we finished our P&A in the first week of February. The rig moved offsite the middle of February, and the first 3D seismic shot was done on the 14th of March. [There was] a month between the first shot of seismic and the end of the work, which is a fantastic performance.
“We also fast tracked the seismic acquisition, so we could start looking at the potential on the new data by June of this year. And that allows us, together with the information that we col- lected, to fast-track well evaluation and put us into position to commission the rig and be able to drill early next year. Doing as many processes in parallel allowed us to save 18 months to two years in the well programme, and I don’t think we can compress that timeline anymore, given the operational constraints and the operational windows for the seismic acquisition.”
With the initial phase of the 3D seismic acqui- sition programme over the basin completed, the Brulpadda well results will be integrated with the 3D seismic data ahead of the drilling programme in 2020, which will include up to three explora- tion wells.
Africa Oil Week, November 25 2019
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Week 47 27•November•2019