Well R101 was spudded at the beginning of October 2005 and reached a depth of 4,579m in mid January. Mud logs indicated more than 200m of gas bearing Tournasian sandstones in a number of intervals from approximately 4,100m; gas shows were recorded at downhole pressures of between 9,000psi and 11,000psi. Drilling was halted at 4,579m when gas was encountered at pressures in excess of 12,000 psi. These pressures exceeded the design parameters for the well and were 30% higher than the maximum values reported in offset wells drilled by Ukrainian State organisations in the 1970s. A cement plug has been set to isolate this lower horizon and a liner has been run and cemented.
The N75 rig is currently being moved to the Molchanovskoye Field to drill the next horizontal producing Well M154 in the northern area of the field. On completion of Well M154, the rig will return to Rudenkovskoye to set the new high pressure casing, prior to logging and testing of the upper horizons of Well R101. Advanced 'through casing' logging techniques will be required as it was not possible to run open hole logs across the upper Tournasian sands prior to well suspension.
The Company is also reviewing options for drilling and testing the underlying high pressure Devonian formations; these include upgrading of the N75 rig or contracting a larger rig with a 15,000psi BOP system.
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