Exploration & Production | Drilling / Well Results | Key Wells | Production Rates
Rocky Results for Serinus' Latest Well
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Serinus Energy Inc. has reported an update on the Winstar-13 well in Sabria Field in central Tunisia.
Production testing of WIN-13 commenced on April 28, 2015, initially through on-site equipment, and was switched into the flowline on May 5th. It is producing 41.5°API light oil and solution gas, consistent with the rest of the field.
The test data to date is summarized in the table below:
Initial flow was mostly water as drilling and completion fluids that had been lost to the formation during those operations were recovered. The water cut has dropped continuously since then to its current level of 19%.
The current oil rate is fluctuating between 125 - 175 bbl/d with a gas-oil ratio of 2,200 ft3 per bbl and a flowing wellhead pressure of 403 psi. In contrast, the Winstar-12bis well averaged 553 bbl/d at a flowing pressure wellhead pressure of 2,550 psi during its first week of production in December 2014.
Management believes that this disparity is due to a combination of wellbore damage and some type of obstruction in the tubing string. This assessment is based on:
- The casing pressures on WIN-13 have been varying between 1,700 - 1,800 psi. This indicates obstruction in the tubing since the friction losses normally expected at these production rates cannot account for this large a difference between the tubing and casing pressures at the wellhead.
- Prior to opening the well for testing, several days of bailing were required in order to reach and remove the plug set in the tubing before the drilling rig moved off. The material recovered during bailing operations was a combination of drilling mud, barite and lost circulation material, with small amounts of formation sand. Management believes that this same combination of material is resulting in significant wellbore damage and inhibiting reservoir inflow.
- The Company is currently preparing a work program using chemical solvents and coiled tubing to address these issues. The requisite equipment and materiel is available in country, and laboratory tests of the solvent on drilling mud samples from both WIN-13 and WIN-12bis have been very encouraging. Operations .are expected to commence in mid to late May. In the interim, the well will remain on production to see if it will continue to clean up incrementally on its own.
- The Sabria Field covers approximately 11,250 acres and is 45% owned and operated by Winstar Tunisia B.V., a wholly-owned subsidiary of Serinus. The other 55% is owned by the Tunisian state oil company, Entreprise Tunisienne D'Activites Pétrolières (ETAP).
Jock Graham, Executive Vice President and Chief Operating Officer of Serinus said: "Although these initial production rates are below expectations, we are encouraged by the high casing pressure and are looking forward to remediating the apparent damage and obstruction issues in WIN-13."