Petroceltic International provided an update on operations at the Ain Tsila field on its Isarene permit (Blocks 228 & 229a) in south eastern Algeria. Petroceltic operates the permit with a 56.625 % interest, Sonatrach holds a 25% interest, and Enel holds an 18.375% interest, pending final Government of Algeria ratification.

AT-7 drilling and logging results

The AT-7 well, a vertical well located in the south west of the Ain Tsila field, commenced drilling on 26 July 2011 and reached a total depth of 2142 m on 17 August 2011. Following logging operations a completion string has been run and the Dalma Rig LR-12 ceased operations on 24 August 2011. This completes the drilling programme for the Dalma Rig.

The well was drilled approximately 12 km south of the AT-3 well and 15 km west of the AT-6 well to appraise the south western extension of the field and targeted a broad structural culmination in the centre of the main Ordovician glacial channel. The principal Ordovician objective was encountered at 1474m TVDSS. A gross reservoir interval of 206m was drilled with a calculated net interval of 93m and net pay of 40m. These results are much as expected.

Following the logging, an open hole packer multi-stage completion was run and the well has been suspended to await testing. The test programme, which will include the hydraulic fracturing of the main reservoir interval, is scheduled for October following the completion of test operations at AT-8.

AT-8 drilling and logging results

The AT-8 well, a vertical well located in the north of the Ain Tsila field, commenced drilling on 19 July 2011 and reached a total depth of 2123 m on 22 August 2011. This is the first well to be drilled with the KCA Deutag Rig T-211.The AT-8 well is located 5km north east of AT-1 and 4.5km north west of the AT-5 well in an undrilled section of the field. It is targeting a structural pop-up feature, and specifically the damage zone of an interpreted seismic fault with the expectation of encountering natural fractures. The top of the Ordovician reservoir was encountered at 1499m TVDSS. A gross Ordovician reservoir interval of 121m was penetrated with 33 m of net sand and 24 m of interpreted net pay. Initial interpretations of a borehole image log indicate the presence of fractures consistent with the pre-drill expectation of a fault damage zone. Reservoir quality is better than anticipated at this location and the well appears to include a unit of improved porosity and permeability at the top of the Ordovician sands.

Following the logging an open hole packer multi-stage completion has been run and the well will be suspended to await testing. The test programme, which will include hydraulic fracturing of the main reservoir interval, is expected to occur after AT-6 testing in September.

The KCA Deutag rig will now move to drill a horizontal well, AT-9, in the centre of the field between AT-1 and AT-2.

AT-6 testing update

The AT-6 well test programme is currently underway. The well was drilled as a vertical well outside the main 3D seismic to appraise the south eastern extension of the field. Test results are anticipated in September.

On completion of testing operations the rigless testing unit will move to the AT-8 well in the north of the field.

Brian O'Cathain, chief executive of Petroceltic commented: "We are pleased with the results to date of the AT-7 and AT-8 wells, both of which were drilled on time and on budget. Based on log analysis, we are in particular encouraged by the preliminary results from the AT-8 well, which have demonstrated a number of characteristics which indicate the potential for positive flow rates. Our appraisal programme is continuing at a rapid pace with four test results and the AT-9 well scheduled before year end."

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