Central Petroleum announces new horizontal drilling plan for Surprise-1

Central Petroleum, (ASX:CTP) fresh from plans to re-enter the Surprise-1 Sidetrack-1 in the Amadeus Basin on Saturday 18 November, has announced horizontal drilling plans for Surprise-1.

The Surprise-1 re-entry is the first of this current liquids focussed drilling programme on Central’s acreage position including Madigan or Simpson East and Mt Kitty.

Previously, it had been planned to drill a sidetrack section in preparation for a possible vertical completion and production scenario.

Now Central intends to drill through the bottom cement plug at (top of approximately 2,300m) to an approximate depth of 2,770 metres in 8.5” hole before running a full suite of electric logs and rotary sidewall cores.

The new direction is due to new chief operating officer Dalton Hallgren and exploration manager Trevor Shortt's North American horizontal and unconventional drilling and completion experience.

“This new well plan devised by Central’s capable technical team gives us the flexibility to apply advanced drilling and completion techniques that have been well understood and widely applied in North America for some time, especially in unconventional plays” said Mr John Heugh, Central’s managing director today.

New plan

Following evaluation of the section from the base of the Mereenie Sandstone to the mid Pacoota Sandstone, 7” casing is planned to be run to the depth of 2,750m before contingently drilling ahead in 6” hole to a Total Depth of approximately 3,450m to evaluate possible Direct Hydrocarbon Indicators (DHIs) in the lower Pacoota Sandstone, the Goyder Formation and the upper section of an interpreted salt dome.

Although the already drilled lower Stairway Sandstone with very positive oil shows may have suffered formation damage from exposure to drilling mud for close to 12 months, the rest of the section will be fresh formation and electric logging will “see” well beyond any potentially damaged zones close to the well bore.

Production from a vertical well bore may be possible, however, if the results of evaluation show that the company could anticipate considerably enhanced production potential there are contingent plans to drill horizontal well bores or high angle slanted directional well bores through selected target zones.

Timeline

Central plans to complete the drilling of Surprise-1 by about mid December 2011, contingent on Total Depth (TD) drilled to and evaluation of ongoing results.

Under the terms of the contract, Hunt Rig 3 is expected to be stacked in Central’s warehouse and yard facilities at Alice Springs during any break in drilling occasioned by the wet season.

Hunt Rig 3 has been extensively refurbished with new or upgraded main motors, rotary table, mud tanks, Blow Out Preventer (BOP) and mud pumps.