West Mailisu #2 Prospect
The West Mailisu #2 prospect in the Kyrgyz Republic lies adjacent to the Mailisu IV oil field, which has produced more than 42mmbbls of oil. West Mailisu #2 is a large structure adjacent to a significant oil field, which if successful, will make a significant impact on Caspian’s Kyrgyz production.
We believe West Mailisu #2 has the potential for oil in Eocene age sands and carbonates (Beds III, V & VII) and gas in the Cretaceous and Jurassic-age sands. The West Mailisu #2 well is targeting oil in Eocene age sands (Bed III) at about 1740m and the carbonate Beds V & VII to 2000m. The targeted feature is defined by a NW-SE trending reverse fault on the northern flank.
The prospect could contain oil reserves of up to 9.7mmbbls, with mean potential reserves of 4.5mmbls calculated for the Eocene reservoirs. Gas reserves of 5-10bcf could also be discovered in the Cretaceous or Jurassic reservoirs. Seismic sections across the structure indicate a robust closure (see figures 2 and 3).
Figure 1 - Time structure map top Eocene Carbonates
Figure 2 - Seismic Line FESN09-02
Figure 3 - Seismic Line CAS10-05
Caspian completed interpretation of the 2010 seismic and spudded the West Mailisu #2 well on 13 June 2011. Good oil shows were encountered over the interval of 1691-1697m in the well. This was initially thought to be Bed II, however further analysis indicated it was more likely to be Bed III, a primary target. The shows were described by the wellsite geologist as “strong oil shows with visible oil in cuttings with a smell of hydrocarbons and bright yellow-bluish fluorescence”.
Fluorescence and gas shows were encountered from the top of Bed V with continued higher gas reading throughout the section carbonate interval (1805-1825m) including Bed VII. However, no further gas or oil shows were observed in the deeper Cretaceous-aged sands.
After perforating Bed III with a shot over the interval 1785-1795.5m, progress on our West Mailisu #2 well was slowed by the unavailability of equipment. However, Caspian recovered oil from the well when it decided to run a low-volume mechanical pump into the well to confirm presence of moveable oil. Using this method, a small volume of oil (about 10 bbls – equivalent to the pump capacity) was pumped from the bore. The oil was essentially water-free and appeared to be heavy crude (API <20˚). Laboratory tests were requested to confirm these observations. During the test, pumping fluid levels were monitored and remained essentially static with a head of about 840m during pumping operations.The use of an air compressor to obtain definitive flow rates proved unsuccessful so Caspian decided to run a PCP downhole pump and put the well into trial production, which is expected to happen in late September or early October. Based on the results of the trial production, a forward plan will be made which could include appraisal/development drilling, in-well-bore radial drilling or fracture stimulation.
Initial estimates suggest that there is a potential mean recoverable resource of 1.0 million barrels, with an upside case of 2.2 million barrels of oil within Bed III of the West Mailisu structure.