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Update: Samson Hits Total Depth at Bluff #1-11 Well; IDs Oil Shows
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Samson Oil & Gas has reported that the Bluff #1-11 well has reached a total depth of 8,900 feet after intersecting pre-Cambrian basement.
Prior to reaching total depth, significant mud losses were observed (150 bbls) at 8,836 feet, which necessitated a trip out to the casing shoe, while the lost mud volume was replaced. On tripping back into the hole at 8,400 feet, the well kicked and was shut in at the surface utilizing the blowout preventer. 1,620 psi was recorded on the annulus at this point, increasing to 2,080 psi with a 9.3 lbs per gallon mud weight recorded.
Loss circulation material was circulated and primary well control was regained and the well was static so that drilling could continue to the total depth and the initial wireline logging program could be initiated. The tool string was unable to get past 7,330 feet on two separate occasions; the second attempt after a clean out trip.
A decision was taken to employ drill pipe conveyed logging tools. Whilst preparations were under way to do a further cleanout trip ahead of this operation, the well flowed with a 9.4 lb. per gallon mud weight in the hole and was therefore shut in at the surface with 200 psi recorded beneath the blow out preventer increasing to 1,100 psi. A surface kill operation is underway.
Various oil shows were recorded in the Permian, Pennsylvanian and Mississippian targets. Oily mud was observed at 8,090 feet and 8,430 feet and the mud analysis recorded up to 5% of contained oil at 8,650 feet. These shows will be evaluated using wire line logs after primary well control is re-established, which is expected to take several days.
Update June 18, 2014
The Bluff #1-11 well has set a drillable bridge plug at 7,160 feet in the intermediate casing and the pressure was bleed off enabling drill pipe to be run into the hole to the top of the plug. Currently the rig is conditioning mud in preparation to drill out the plug and to prepare the open hole for logs.
During the well control operations last evening a gas sample was obtained, and has been analyzed and has determined a 97% nitrogen content with 2% methane and heavier hydrocarbons. The generation of nitrogen is thought to be associated with dolomitic zones that are encased in anhydrite.
The proposed drill pipe conveyed logging program will enable the various oil shows that were recorded in the Permian, Pennsylvanian and Mississippian targets to be evaluated. Oily mud was observed at 8,090 feet and 8,430 feet and the mud analysis recorded up to 5% of contained oil at
8,650 feet.
