Nostrum acquired the asset in 2023 and has since conducted appraisal activities to refine the development plan, leveraging its existing infrastructure at Chinarevskoye. The asset comprises multiple discovered hydrocarbon accumulations across the Permian Artinskian, Filippovski, and Kalinovski reservoirs in the West Kazakhstan Region. The governing licence remains valid until December 2044.

The Stepnoy Leopard CPR, an independent third-party evaluation of the reserves and resources of the SL fields as at 1 January 2024, was prepared by Xodus Group Limited.

A summary of the Reserves associated with Stepnoy Leopard, on a gross and working interest basis, is shown in Tables 1 and 2. The reserves are an arithmetic summation of the economically recoverable resources for five different fields in Stepnoy Leopard, including the four eastern Artinskian fields and the Kamenskoye field in the west of the area.

Reserves by Reservoir

Artinskian Reservoir: Contains the majority of the Petroleum Initially-In-Place (PIIP).

Massive stromatolitic reefal carbonates (dolomites and limestones) were deposited in the final stage of Moscovian-Artinskian carbonate cycle, which built a broad shelf along the northern part of the Pre-Caspian basin. These carbonates build a long chain of barrier reefs, separated by perpendicular passages to the shoreline acted as current channels, forming a rim along the shelf edge. Shelf rims rises from 150 m to almost 300 m above shelf table. Reservoir rocks are fractured, which greatly contribute to their permeability. In general, vugs and fractures are unevenly distributed and are controlled by the primary reefal macro-structure.

Filippovski Reservoir: Holds a subordinate volume of PIIP. Dolomite formations within occasionally dolomitic limestones above Artinskian and partially onlapping. Gradually thickens away from the Artinskian shelf rim to the North-West and reaches 250 m within the boundary of the licences block. It was deposited within a broad shelf lagoon in the North-West of the Artinskian barrier rim.

Kalinovski Reservoir: This overpressured reservoir, which occurs only in the Kamenskoye field, has a proven hydrocarbon accumulation in a thick,
salt-entrapped carbonate-clastic sequence (Lower Permian Kungur), which is influenced by salt tectonics. The subordinated clastic horizon is thin and located at the bottom of the sequence.

Economic Evaluation

The Net Present Value (NPV) at a 10% discount rate for the Stepnoy Leopard reserves is summarised below:

The project economics are based on Brent Oil Forward Curve pricing (as of May 2024) for oil and condensate, with domestic pricing for gas and LPG set by Kazakhstan’s Ministry of Energy. The reserves estimates reflect an economic cut-off, ensuring commercial viability under the current fiscal regime.

Field Geology & Development Potential

The Stepnoy Leopard fields consists of eight hydrocarbon-bearing structures in which the Artinskian, Filippovski and Kalinovski reservoirs may be formed. Reserves have been identified for only 5 structures (4 eastern – Artinskian reservoir and Kamenskoye – Kalinovski reservoir), while the 3 western structures only hold resources. The primary reservoirs are carbonate formations, characterised by a high degree of reservoir properties heterogeneity and partially high fracture permeability. Initial geological studies and dynamic modeling indicate strong reservoir continuity, supporting long-term production potential.

A phased drilling campaign is planned, focusing first on the eastern Artinskian fields and the Kamenskoye field. Infrastructure development includes well tie-ins to existing processing facilities at Chinarevskoye, which will enable efficient hydrocarbon extraction and transportation.

Contingent Resources & Long-Term Outlook

In addition to booked reserves, Contingent Resources in the western Artinskian fields and post-licence production opportunities amount to 361.76 BCF of raw gas (2C) and 7.05 MMSTB of condensate & oil (2C). These volumes represent future development potential, subject to additional appraisal activities and regulatory approvals.

Future Work & Strategic Focus

Nostrum is committed to maximising value from the Stepnoy Leopard fields through a phased development approach, starting with the eastern Artinskian fields and the Kamenskoye field. The company is also exploring post-licence production opportunities in the western Artinskian fields.

• Drilling & Appraisal: Drilling of new wells with well data acquisition and continuous geological work to optimise reserve estimates.
• Infrastructure Optimisation: Expanding processing capacity and integrating Stepnoy Leopard production with existing Nostrum assets.
• Regulatory Compliance & Sustainability: Ensuring all operations align with Kazakhstan’s environmental and fiscal frameworks.
• Reserves Growth Strategy: Continuous assessment of new drilling targets (deep potential) and enhanced recovery techniques to maximise field output.

Table 1 – Reserves summary (Gross)

Table 2 – Reserves summary (80% Working Interest)