Friday, June 03, 2011
Sterling Resources Ltd.
by SubseaIQ
Sterling announced the completion of drilling of the 210/30a-4X well on Block 210/30a in the United Kingdom North Sea. This is the fourth well (third side-track) drilled in the current four well campaign to further appraise the extent of the Cladhan reservoir.
The 210/30a-4X well was drilled in the most southern limit of the northern core area in a potentially separate channel, utilizing the Transocean Prospect rig. The objectives of the 210/30a-4X sidetrack well were to core the full reservoir section approximately one kilometer south and approximately 60 feet updip of the oil bearing 210/30a-4 well, and evaluate the southern fringe of the northern core area.
The 210/30a-4X well was drilled to a total measured depth (MD) of 10,614 feet encountering 171 feet gross, 105 feet net (vertical thickness) of high quality Upper Jurassic sands. Almost 180 feet of core was successfully recovered across the full reservoir section.
Petrophysical analysis of the interval showed five feet of oil-bearing sand at the top of the interval with an Oil-Down-To at 10,177 feet True Vertical Depth Subsea (TVDSS). An oil sample was obtained from the interval. A further 100 feet of water-bearing sand was encountered below thin shale which separates the top and bottom sands. A clear contact has not been observed although the top and bottom sands appear to be in pressure communication. The presence of a known Oil-Down-To bodes well for updip oil in other channels with the same pressure regime.
Generally, reservoir quality is very good with porosities up to 25 percent, substantiated by measurements obtained while taking fluid samples. These pressure measurements also confirm that the interval is over-pressured on trend with the 210/30a-4Y well, but some 900 psi lower than the discovery area. The implication of this information is that the southern fringe of the northern channel area is in communication with the central channel, being distinct from the main reservoir in the northern channel area. The well will be suspended for possible re-use as a future development well at this location or elsewhere after a sidetrack. With the completion of this four well drilling campaign, RPS Energy will start a review of the Cladhan resources with the intent of publishing an update report within a few weeks.
"Notwithstanding the presence of predominantly wet sands at this depth in this separate channel compartment, we are encouraged by the presence of oil in the top sand and by reservoir quality at this location. Further updip prospectivity is certainly promising," remarked John Rapach, Sterling's Chief Operating Officer. "We have proved that our current seismic model can adequately predict sand thickness but reservoir quality definition is now paramount for further appraisal and development drilling. Our next planned subsurface activity is to complete full reprocessing and interpretation of the existing seismic dataset incorporating all of the log, core, fluid and pressure results obtained during this current drilling campaign. Consequently, the next drilling campaign will probably commence in early 2012," noted Mr. Rapach.
"Our development planning is concentrating on either a subsea tie-back or FPSO development of the main northern core area with further definition of reserves and resources during our next drilling campaign. We are commencing pipeline route and environmental survey work within the next few weeks," added Mr. Rapach.
Mike Azancot, Sterling's Chief Executive Officer, commenting on these results noted, "The current exploration and appraisal drilling campaign on Cladhan has been successful in increasing the height of the oil column by 798 feet to 1228 feet in total. The extent of the development of the northern core area is now better defined with this increase in oil column. The fan area in the east of the field remains prospective as the results from the 210/30a-4Z well drilled in this campaign are not conclusive due to its proximity to a major fault. Our plan towards development with options for increased resource exploitation after further drilling is now underway with a target for first oil in 2014."
Sterling holds a 39.9% interest in license P1064 which contains Cladhan, and is the operator. The partners are Wintershall (UK North Sea) Ltd. with 33.5 percent, Encore Petroleum Ltd with 16.6 percent and Dyas UK Ltd with 10.0 percent.
Oil & Gas Post
Promote Your Page Too
No comments:
Post a Comment