Sterling Resources has successfully completed the Ana-2 appraisal well, in the Romanian Black Sea. Ana-2 was drilled as a follow up appraisal well following the Ana-1 discovery well which was drilled and tested earlier this year using the Prometeu jackup.
The Ana-2 well encountered gas within the Doina Main Sand Formation at 1,121 metres true vertical depth subsea (TVDss), some 10 metres shallower than originally mapped. The well has been extensively evaluated with electric logs, MDT pressure tests and a collection of wireline gas samples. These results confirm the presence of a 39 metre gas column with a net pay of 23 metres in high quality reservoir sands with porosity of up to 32% and good permeability. The pressure data also confirms a gas water contact consistent with the earlier Ana-1 well. The reservoir sands encountered in the Ana-2 well are equivalent to, or slightly better, than those encountered in Ana-1. The original Ana-1 well tested gas, at rates up to 20 million cubic feet of gas per day (MMcf/d) under conditions restricted by equipment. Under unrestricted conditions, a final completed rate in excess of 30 MMcf/d per well is anticipated.
The Ana-2 well also encountered a 5 meter gas bearing reservoir in a shallower horizon at 766 metres TVDss. This shallower horizon was also present in the Ana-1 well and will be further evaluated, in order to determine its feasibility as a new reservoir.
The well reached a total depth of 1,600 metres on September 10th and was located approximately 750 metres north west of the original Ana-1 seabed location. Following conclusion of the successful acquisition of the logging suite, the well is now being suspended and rig release is expected by the end of the week. As previously reported, Ana-2 was directionally drilled from a seabed template which provides re-entry capability for both of the Ana wells for future production.
"We are pleased with the drilling results from Ana-2 as they confirm the continuity of the reservoir sands and our theory that this area of the field may be higher than originally mapped. The well has proven positive on both accounts and we will be able to upgrade our gas in place estimates for the field based on the results of this successful well," stated Stephen Birrell, Sterling's Vice President of Romanian Operations.
"The Ana-2 well was drilled using directional technology to test the feasibility of deviated wells through the shallow overburden, above the field. The success of the well has confirmed our ability to develop this field using directional wells from a common drill centre. This will permit us to optimize future field development," commented John Rapach, Vice President of Operations for Sterling.
Stewart Gibson, Chief Executive Officer of Sterling, saluted the team responsible for the successful completion of Ana-2: Grup Servicii Petroliere S.A. (GSP), the drilling contractor, North Sea Well Engineering Ltd. (Norwell), Sterling's drilling management team, and all of the subsurface and operational staff. "On behalf of Sterling we wish to express thanks to all of the members of this team, whose diligence and technical expertise resulted in the successful execution of the Ana-2 well," noted Mr. Gibson.
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