The Kul-Bas Exploration and Production Contract area surrounds the Akkulka Block. This large area remains underexplored and has very prospective exploration.
The Kul‐Bas block is a large exploration area of approximately 7,632 sq. km. There was already reasonable seismic coverage over the area and the Company had reprocessed these vintage data as well as acquiring and interpreting over 700 km of new 2D seismic here and in the Akkulka block identifying several prospects at both shallow and deep levels. The Kalypso (KBD-01) wildcat exploration well was the first deeper exploration well drilled by Tethys on this block. The well, drilled in 2011, is located on a large structure some 50 km to the north west of the Doris oil field in the Akkulka block which produced over 4 million barrels of oil. Electric logs indicate two potential Jurassic targets and some potential 100m of gross pay from a depth of 4,128 metres in what is interpreted to be Permo-Carboniferous limestones. The well was unable to be completed due to technical issues.
The company also identified the “Klymene” prospect which is located to the west of the producing assets in the Akkulka block. The prospect was identified from acquired and interpreted seismic and indicated a four-way closure with bright spots at 2 of 3 prospective stratigraphic levels within the Cretaceous and Jurassic sequence, both of which have been productive in the Company’s Doris oilfield some 60 km to the east. The Klymene prospect has the potential to be an order of magnitude bigger than the Doris oil field and surrounding prospects in the Akkulka block (the geographical area of the prospect is up to ten times the areal extent of the Doris oil field).
The Klymene (KBD-02) exploration well was drilled to a depth of 2,750 metres in December 2019. The well was tested from April to December 2020 producing over 380,000 barrels of oil at rates of up to 4,000 bopd from three productive zones.
Subject to Tethys securing financing, the company is planning to drill four wells in 2021 in the Kul-Bas field at distances of approximately 500-2000 meters away from KBD-02 (KBD-03, KBD-06, KBD-07, and KBD-08).
The Kyzloi and Akkulka development is one of the first dry gas developments carried out in Kazakhstan with one of the first tie-ins by a non-State company to a major gas trunkline in Central Asia. Production commenced in December 2007.
Kyzyloi and Akkulka fields contain sweet (no sulphur), dry natural gas at shallow depths of up to 610 metres making for relatively low development and operating costs. The Kyzyloi and Akkulka fields are tied in to the major Bukhara-Urals gas pipeline by a 56 km pipeline owned and built by the Company and with a design capacity of up to 2.0 million cubic metres per day. Gas is pumped into the Bukhara-Urals trunkline at the Company’s Booster Compressor Station (BCS) at 910 km on the trunkline. The BCS consists of five separate compressor units plus continuous gas composition and flow measurement fully integrated into the Bukhara-Urals gas export system. The Company has been very successful in exploring for new gas in the area.
The AKD-01 well was the first deep exploration well drilled under the Akkulka Exploration Contract on the Akkulka block and has produced in excess of 4 million barrels of oil.
AKD-01 encountered two oil bearing zones, the lower zone being an Upper Jurassic carbonate sequence at approximately 2,355 metres and an upper, Lower Cretaceous sandstone zone at approximately 2,174 metres. Oil shows were also encountered in the Triassic sequence but not tested. Oil quality is very good in both zones, with the lower zone having 46 degree API low sulphur crude and the upper zone 37 degree API low sulphur crude.
The upper lower Cretaceous sandstone interval showed extremely good permeability (in excess of 1.0 Darcy) and a large investigated distance and therefore a large connected volume, that indicates a very high quality laterally extensive reservoir. The lower carbonate zone also showed good permeability with a large investigated distance and significant connected volume.
The Company produced oil under a Pilot Production Contract and oil from the same Doris discovery horizons has tested successfully from wells AKD-05 and AKD-06 and there is a further discovery, Dione, in an Upper Jurassic sand in well AKD-03.
There is very good potential exploration in the area. Further similar prospects have been mapped in the Akkulka and Kul-Bas block near to Doris. A full appraisal programme on the Doris oil discovery, the Dione field south of Doris and further exploration on the Akkulka block is subject to funding.
The AKD-12 well drilled at Akkulka in 2020 has been tested and has produced gas at a rate of approximately 29.4 thousand cubic meters per day using a 6mm choke, and approximately 34.5 thousand cubic meters per day using an 8mm choke. The interval perforated was 587.97-592.57 meters. The company is planning to complete the AKD-12 test and then contract this rig to spud the next well at Akkulka. This new well will target the same shallow gas zone (approximately 600 meters). The AKD-12 well will not likely go into production until 2022. This well is in a new structure and will require new approvals as well as construction of a new pipeline to the well. The plan is to drill additional offset wells to AKD-12 to develop this new structure.