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Schlumberger releases Phase 1 of Pantheon reservoir modeling
Kay Cashman Petroleum News
AIM-listed Pantheon Resources plc, whose Alaska operator is Great Bear Pantheon, said Dec. 12 that it has received a completed Phase 1 reservoir modeling report from Schlumberger on its three North Slope project areas - Alkaid unit, Theta West leases and Talitha unit.
The three project areas encompass the following four distinct oil reservoirs: Alkaid, the Slope Fan System, the Shelf Margin Deltaic, or SMD, and the Basin Floor Fan system.
(See graphic in the online issue PDF)
Overall, the Schlumberger modeling estimates the reservoirs contain 17.8 billion barrels of net oil in place, or OIP, versus Pantheon estimates of 23 billion barrels of OIP.
The Schlumberger model OIP numbers are approximately 70% of Pantheon’s estimates for the Theta West (Lower Basin Floor Fan) which accounts for the primary variance between the overall Pantheon and Schlumberger estimates.
Schlumberger’s OIP estimates for Theta West were constrained to the project’s 3D footprint with more conservative reservoir parameters than Pantheon’s at the lease boundaries. With additional drilling data points, potential exists for Schlumberger’s modeling estimates to increase in the future, Pantheon said.
The company believes that the reservoir improves in quality to the north of the Theta West 1 well, both within and outside its current leasehold, which is the primary reason Pantheon bid on new acreage in the area in the November 2022 state of Alaska oil and gas lease sale
The recently acquired acreage and its resource potential is not considered in the Schlumberger report, nor Pantheon’s current estimates.
The next Schlumberger project phase, “commencing shortly,” will address these differences along with developing a dynamic development model to predict overall recoveries, Pantheon said.
No recovery numbers in Phase 1 Schlumberger did not provide an estimate on oil recovery, which was outside the scope of this first phase of the project. Schlumberger’s work is ongoing, and the recovery factors will be covered in the next phase of their work, Pantheon said.
“For illustrative purposes only, applying Pantheon’s estimated 10% recovery factor to Schlumberger’s estimated 17.8 billion barrels of oil in place would imply the Pantheon leasehold has the potential to contain 1.78 billion barrels of recoverable oil,” Pantheon said.
Alkaid 2 update Pantheon said it is currently in a production testing operation at the Alkaid 2 well.
As previously reported, operator Great Bear Pantheon utilized a coiled tubing unit to remediate a sand blockage inside the horizontal production liner.
“Ideally, a workover rig would have been used to remove the production tubing in a relatively straightforward operation to clear the blockage without the constraints of working inside the tubing. However the lack of availability of a suitable workover rig caused the company to use a CTU which is a more delicate and potentially less effective method,” Pantheon said.
“Fortunately, the CTU was effective in clearing most, but not all, of the blockage and flow testing has resumed. The well is still early in the cleanup phase with encouraging initial results,” Pantheon said.
The company cautions that despite early positive data, a definitive assessment of commerciality cannot be made until flow testing operations have concluded.
Individual well recoveries In addition to their modeling of oil in place in Phase 1, Schlumberger also modeled individual well recoveries for three separate reservoirs over an illustrative one-mile lateral length (c. 5,300 feet).
While a “nominal” one-mile lateral has been used as the basis for modeling, longer lateral lengths are expected to yield higher production volumes, Pantheon noted that its development plan is based on what it believes is the optimum lateral length of 8,000 to 10,000 feet:
Six month project Pantheon engaged Schlumberger to undertake this project more than six months ago in order to develop a highly detailed body of work to assist in reservoir modeling, development modeling and as “an important tool in Pantheon’s data room to allow potential future farm-in partners to gain a greater understanding of the potential, characteristics and scale of Pantheon’s projects,” Pantheon said.
Schlumberger’s Phase 1 report “represents the most comprehensive model completed on evaluating the discovered oil resource and the productive potential” of Pantheon’s North Slope acreage, Pantheon said.
The model is “extremely detailed, comprising c. 13 million individual three dimensional cells within the c. 153,000 acres of Pantheon’s current North Slope leasehold.”
Developed over the past six months, the model involved in excess of 1,000 man-hours with a team of reservoir, geological and geophysical specialists at Schlumberger.
Phase 2 of the project will similarly require significant man hours over a number of months.
Bob Rosenthal, Pantheon’s technical director, was quoted as saying the following in the company’s Dec. 12 announcement: “I have been beyond impressed with the quality of work and the attention to detail shown by the Schlumberger team. The amount of time and effort to develop this model is extraordinary. It will significantly enhance the intended future farmout process as this model provides potential farm-in companies industry validation, confidence in the data and the project potential. Companies can use this giant model to manipulate parameters/assumptions for their own analysis. I can’t wait to start working with them on the next phase of the project which will, amongst other modeling, predict overall reservoir recoveries. I believe our current estimate of 10% has the potential to be conservative based on what we are seeing at the moment and again remembering we are using unconventional technology on conventional reservoirs.”
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