Australian oil and gas company Buccaneer Energy Limited has announced that it has stopped drilling operations at its Cosmo #1 well, in the Cook Inlet, off Alaska.
Drilling, originally planned to be completed at 6,000′ Total Vertical Depth(TVD) before setting casing, was stopped at 5,600′ TVD due to encountering oil / condensate shows in the Lower Tyonek formation ~400′ higher than expected.
The company stated in a press release that it is now getting ready to run wire line logs, carry out pressure tests and side wall cores in gas sections.
According to the report, three primary gas zones totalling 175′ have been penetrated while drilling. The Logging While Drilling (“LWD”) equipment indicated good resistivity, permeability and porosity characteristics. These results need to be confirmed with wire line logs and flow testing, if warranted.
The gas zones were all accompanied with a sharp increase in gas, relative to background gas measurements, prior to intersecting each gas zone. Generally, gas levels over background gas amounts increased by a multiple of 5-10 times, measured resistivity from 10-30 ohms, and permeability and porosity characteristics would indicate production capable sands based on previous basin experience.
There are 4 additional potentially gas bearing zones of interest, similar in total thickness to the primary zones, which the Company classifies as secondary zones of interest.
On completion of drilling and logging operations the well will be plugged back to the bottom of the Tyonek gas productive zones. Gas zones within the Tyonek Formation that are identified as potentially commercial through drilling and logging will then be perforated and flow tested. The well will then be temporarily abandoned as a future gas producer.