Pantheon Resources PLC will start Ahphun field development on Alaska's North Slope after identifying oil and gas reservoirs in the Dubhe-1 appraisal well.
The first phase of the well program consisted of a deviated pilot hole to gather cores and logs to select the optimum landing zone for a subsequent lateral sidetrack in the primary SMD-B zone, the company said in a release Aug. 18. The pilot hole was drilled, logged, and cored to 12,833 ft MD, equivalent to 8,699 ft TVD.
The primary target of the well was the topset horizon (SMD-B), appraising the already discovered resource. Additionally, the well was designed to encounter three further exploration horizons (Prince Creek, SMD-C, and the Slope Fan System), none of which have previously had resource estimate attributed to them.
Preliminary analysis indicates that Dubhe-1 intersected multiple hydrocarbon bearing horizons over about 2,143 ft MD (1,085 ft TVT). In addition to the primary SMD-B objective of the well, multiple reservoirs were penetrated in this overall section consisting of interbedded sands and shales. All intervals were logged with a full suite of logging while drilling (LWD) tools and volatiles analysis service (VAS) of both sealed and unsealed cuttings samples.
Analysis of the thickness and quality of the primary target topset confirms that the SMD-B has exceeded pre-drill expectations. The gross thickness of the hydrocarbon column in this interval was measured at 565 ft true vertical thickness (TVT), exceeding the 450 ft TVT pre-drill expectation by 26%. Reservoir properties are consistent with the nearby Pipeline State #1 discovery well.
Additional hydrocarbon bearing zones were encountered in the SMD-C and two Slope Fans. These horizons were not included in the Ahpun estimated contingent resources of 282 MMbbl and 804 bcf. These resources represent material upside potential as co-development opportunities alongside the established Ahpun SMD-B primary reservoir.
Pantheon intends to drill and subsequently flow test the planned sidetrack lateral in the 565 ft TVT thick section of the SMD-B horizon to refine the production well type curve. In addition to the logs, cores, cuttings, and other data collected in the pilot hole, data gathered from the drilling of this horizontal lateral will be further integrated into the analysis. The lateral will be hydraulically stimulated.
Whole core and sidewall core data, VAS analysis of cuttings, LWD and wireline logs, and seismic check shots will calibrate the proprietary 3D survey and reservoir fluid analysis (PVT). These analyses will be used to refine the dynamic reservoir model and design permanent production infrastructure as the capital program transitions to Ahpun field development, the compay said.
Pantheon Resources has 100% working interest in Kodiak and Ahpun projects (OGJ Online, Mar. 3, 2025).
