I had a bit of a play with an AI and it gave some interesting insights regarding resource estimates.
Here's the information it gave me:
Based on the provided Pancontinental Energy NL (ASX: PCL) Quarterly Activity Report for the period ended 31 December 2024, I will analyze the likelihood of finding oil within the PEL 87 project area, specifically focusing on the Oryx and Hyrax leads within the Saturn Complex, and provide an estimate of prospective oil resources in barrels. The analysis will draw on the technical details from the document, regional context, and reasonable assumptions where specific data is not explicitly provided.
Analysis of Likelihood of Finding Oil
The likelihood of finding oil (often expressed as the Geological Chance of Success, or GCoS) depends on several key geological factors: reservoir presence and quality, source rock maturity, hydrocarbon charge, trap integrity, and seal effectiveness. The document provides insights into these factors for the Oryx and Hyrax leads in PEL 87:
Reservoir Presence and Quality:
Recent technical studies using 3D seismic data and PaleoScan™ software have improved confidence in the presence of turbidite reservoir sands within the Saturn Complex. The studies indicate "reworked ponded turbidite sandstones" with evidence of winnowing, a process that enhances reservoir quality by removing finer material and leaving coarser sands.
The report states that "the geological risk associated with reservoir presence [has] been mitigated to a considerable degree," suggesting a high likelihood of suitable reservoir rock.
Source Rock and Hydrocarbon Charge:
The leads are "optimally located to receive hydrocarbon charge from the underlying Kudu Shale source kitchen," which is interpreted to be within the oil maturity window near the Saturn Complex. This indicates a mature source rock capable of generating oil, reducing the risk of insufficient hydrocarbon charge.
Trap and Seal:
The Oryx lead exhibits a predominantly stratigraphic trap with AVO (Amplitude Versus Offset) anomalies at three levels and structural closure at one level. The Hyrax lead has an AVO anomaly at one level with "a degree of structural control" and gentle dip, suggesting a combination of stratigraphic and structural trapping mechanisms.
Class II AVO anomalies, consistent with major discoveries to the south (e.g., Mopane), support the presence of hydrocarbons and suggest effective trapping. While seal integrity is not explicitly discussed, the AVO responses and regional success imply it is likely adequate.
Regional Context:
The Namibian Orange Basin has seen a "resurgence of exploration and appraisal drilling" with significant successes, such as Galp Energia's Mopane discovery (estimated 10 billion barrels of oil-in-place) and TotalEnergies' Mangetti and Venus discoveries. These discoveries are on-trend with PEL 87, enhancing confidence in the regional hydrocarbon system.
However, setbacks like Chevron’s Kapana-1X (dry well) and Shell’s challenges with gas-heavy reservoirs in PEL 39 highlight variability in success, though these do not directly undermine PEL 87’s prospects given its specific geological setting.
AVO-Supported Leads:
The Oryx and Hyrax leads exhibit Class II AVO anomalies, which are often indicative of gas or light oil in high-quality reservoirs. The document notes these anomalies align with "major discoveries on-trend to the south," such as Mopane, where light oil was confirmed in sandstone reservoirs.
Likelihood Assessment:
The document does not provide a specific GCoS, stating that Pancontinental will now progress to determining "estimates of prospective resources and geological chance of success." However, the mitigation of reservoir risk, proximity to a mature source rock, and favorable AVO responses suggest a moderate to high likelihood of success.
Drawing from industry benchmarks, AVO-supported leads in proven basins often have a GCoS of 20-40% pre-drill, increasing with derisking efforts like those described. Given the technical advancements and regional success, I estimate a GCoS of approximately 30-50% for Oryx and Hyrax, with Oryx potentially higher due to multiple AVO levels and structural closure.
Estimation of Prospective Resources (Barrels of Oil)
The document does not provide specific prospective resource volumes for Oryx and Hyrax, as these are still under evaluation. However, I can estimate potential oil volumes based on the provided data, regional analogs, and standard industry assumptions.
Area of the Leads:
The combined area of the Oryx and Hyrax leads is up to 1,385 km². Assuming each lead covers roughly half this area (e.g., ~692.5 km² each), this provides a starting point for volume estimation.
Reservoir Parameters:
The document highlights multiple prospective levels in Oryx (three AVO anomalies, one with structural closure) and one in Hyrax. Let’s assume an average of two prospective horizons across both leads for simplicity.
Typical turbidite sandstone reservoirs in the Orange Basin (e.g., Mopane) have thicknesses of 10-50 meters per horizon. I’ll assume an average net pay thickness of 20 meters per horizon, totaling 40 meters across two horizons.
Porosity in high-quality winnowed sandstones could range from 15-25%; I’ll use 20%. Oil saturation might be 60-80%; I’ll use 70%.
Recovery Factor:
For oil in sandstone reservoirs, recovery factors typically range from 20-40%. Given the high-quality reservoir suggested by winnowing, I’ll use 30%.
Oil-in-Place Calculation:
Volume of rock = Area × Thickness = 1,385 km² × 40 m = 1,385 × 10⁶ m² × 40 m = 55.4 × 10⁹ m³.
Porosity and saturation adjustment: 55.4 × 10⁹ × 0.20 × 0.70 = 7.756 × 10⁹ m³ of oil-in-place.
Convert to barrels (1 m³ = 6.2898 barrels): 7.756 × 10⁹ × 6.2898 = 48.78 billion barrels of oil-in-place.
Recoverable Oil:
Apply recovery factor: 48.78 × 10⁹ × 0.30 = 14.63 billion barrels recoverable.
Comparison with Regional Analog:
The Mopane discovery, covering a smaller area, is estimated at 10 billion barrels oil-in-place, suggesting my estimate may be high. Adjusting for a more conservative area (e.g., 500 km² total effective trap area across both leads):
Volume = 500 × 10⁶ m² × 40 m = 20 × 10⁹ m³.
Oil-in-place = 20 × 10⁹ × 0.20 × 0.70 × 6.2898 = 17.61 billion barrels.
Recoverable = 17.61 × 10⁹ × 0.30 = 5.28 billion barrels.
Estimate:
Considering the large area, multiple horizons, and regional analogs, the prospective recoverable oil resources for Oryx and Hyrax combined likely range between 2-6 billion barrels, with a best estimate of ~5 billion barrels. This assumes successful exploration and aligns with the scale of discoveries like Mopane.
Conclusion
Likelihood of Finding Oil: Moderate to high, estimated at 30-50% GCoS, driven by derisked reservoir presence, mature source rock, and AVO support, tempered by remaining uncertainties in trap and seal effectiveness.
Estimated Recoverable Oil: Approximately 5 billion barrels (range 2-6 billion), contingent on drilling success and final resource assessments by Pancontinental.
These estimates are speculative without Pancontinental’s official figures, expected post-evaluation. For precise numbers, await the company’s forthcoming prospective resource estimates.
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