Trillion Energy International Inc. is formulating a comprehensive redevelopment program for the South Akcakoca Gas-Basin (SASB) gas fields in the Black Sea to increase production levels by accessing additional proven gas reserves.
The company conducted operations to extend the life of the Phase I and II wells by lowering producing pressure to increase gas production, which resulted in a 50% production increase (555 Mcfd increase) to 1,517 Mcfd.
SASB gas field wells first started production between 2007 and 2011 and have produced a total of 41.66 bcf to date, an average of 4.166 bcf/well. The company recently completed a forecast for total economic recovery per well of 5.814 bcf for the 10 production wells drilled during Phase I and II development. Production from Phase I and II peaked in 2011 at 6.5 bcf/year and now currently produce 400 MMcf/year.
SASB consists of 23 shallow water wells, four offshore platforms, related pipelines and a gas processing plant for a to-date total development cost of $608 million.
The natural gas is produced from Eocene age sandstone reservoirs at subsea depths of 1,100-1,800 m in each of the wells. The wells are shallow water in less than 100 m depth. The 12,385-hectare SASB development license is 100% covered by 3D seismic.
Phase I development included partial development of the three nearer shore gas fields, Ayazli (discovered in 2004), Dogu Ayazli (discovered 2006), and Akkaya (discovered in 2005), with first gas in 2007. A total of 17 wells were drilled in Phase I to an average depth of 1,500 m subsea.
Phase II consisted of the deeper water Akcakoca field (discovered in 2006) which was developed with Phase II gas production coming online in 2011. Six wells were drilled and one platform was constructed during the phase.
In total, an 82% success rate occurred in drilling the wells for Phase I and II and finding gas based on the 3D seismic. Several prospects and field extensions were identified by 3D seismic, however, were not drilled at the time.
Trillion Energy is a 49% owner of the SASB natural gas field.
