South Akcakoca Gas: A Black Sea Discovery 30 Years in the Making

Michael J. Fitzgerald¹, Ed Ramirez¹, William Moulton², and Al Garcia^3
1Toreador Resources Corp, Dallas, TX
²Independent Consultant, N/A,
³Integral Technology Group, N/A,

Six Eurasian countries surround the Black Sea. Of those six countries, the Republic of Turkey has the longest coastline, 1595 km. of any bounding country. Prior to 2004 there had been only six well drilled in the Turkish Black Sea, four in the far western Black Sea area and two in the west central area offshore from a small vacation town, Akcakoca.
The Akcakoca #1 and #2 wells had been drilled in the mid-1970's designed to test Mesozoic and Cenozoic sediments seen onshore in outcrops and the subsurface. Early seismic had indicated the presence of sizable structures formed by compressional tectonics bounded by trust faults. The Akcakoca #1 well encountered gas shows in Eocene clastics from 1000m to 1400m and tested 3.25mmcfpd during an open-hole DST. The Akcakoca #2 well encountered gas shows but no tests were run.
In 2000 Madison Oil Turkey, later merged with Toreador Resources, acquired a 962,000 acre permit that contained the Akcakoca wells. Utilizing existing seismic and the original wells Toreador explorationists determined that potential existed for a significant accumulation. A conventional 2-D seismic survey and follow-up high resolution 2-D surveys enabled geophysics to map velocity anomalies that could be tied to the 1970's wells.
In 2004 the Ayazli #1 wildcat was drilled on a thrusted anticline 3 km south of the original Akcakoca #1 well. This well tested approximately 12.0mmcfgpd from four Eocene age sands. Drilling over the next two and a half years saw the exploration group drill 12 successful well out of 14 and initiate the first gas production in the Turkish Black Sea.
This paper will review the geology and geophysics that went into this effort.

AAPG Search and Discovery Article #90072 © 2007 AAPG and AAPG European Region Conference, Athens, Greece