Cairn Energy plc has revealed that the SNE-3 appraisal well offshore Senegal has flowed thousands of barrels of oil as a result of two drill stem tests within its upper reservoirs.
DST 1a produced a maximum flow rate of around 5,400 barrels of oil per day (bopd) and a main flow rate of approximately 4,000 bopd over a 24 hour period from a 49-foot zone. The second drill stem test, DST 1b, covered an additional 18-foot zone and delivered a maximum flow rate of around 5,200 bopd, with an associated main flow rate of 4,500 bopd over a six hour period. Both main flow periods utilized a 56/64” choke.
Multiple samples of oil and gas were recovered to the surface from the drill stem tests and wireline logs, according to Cairn, which confirmed that SNE-3 holds a similar reservoir quality to the SNE-1 and SNE-2 wells. The energy company also stated that initial indications confirm the same 32 degree API oil quality as seen in the previous two wells.
Commenting on the tests at SNE-3, Cairn Energy Chief Executive Simon Thomson, said in a company statement: “Cairn is delighted with the flow rates from the latest well in the Senegal appraisal program, which validate the scale and growth potential of the SNE field.
“The results have demonstrated the ability of the upper reservoirs to flow at commercially viable rates and we eagerly look forward to the results of the BEL-1 well which will commence operations shortly.”
Following the latest development at SNE-3, resource estimates for the SNE field will be revised and an update will be announced at Cairn’s preliminary results March 15. Last month, best estimate 2C contingent resources at Cairn’s SNE oil discovery increased by 42 percent to 468 million barrels of oil, according to an independent resources report from RISC Operations Pty Ltd.
The report, which incorporated recent data available from wells SNE-1 and FAN-1 and reprocessed 3D seismic, also outlined 1C contingent resources of 240 million barrels of oil and 3C resources of 940 million barrels of oil. Australia’s FAR Ltd, which commissioned the report, has estimated that the SNE oil field minimum economic field size is approximately 200 million barrels of oil. FAR, one of Cairn’s joint venture partners in Senegal, has requested RISC to update its independent assessment of SNE contingent resources following results from each of the wells in the ongoing three well SNE appraisal program.
RISC’s Independent Resource Report notes that the SNE field contingent resource estimates have not been updated to reflect the results of the SNE-2 appraisal well or any other changes since December 2015, and that new data may materially impact these contingent resource estimates.
Following its discovery at SNE-1 in 2014, Cairn announced Aug. 18, 2015 that it had reached an agreement with the government of Senegal over an extensive evaluation plan, which commenced in September 2015 with a new 3D seismic survey over the Sangomar Deep, Sangomar Offshore and Rufisque Offshore permits. Final processed products from this survey are expected to be available by mid-2016.
The evaluation plan includes the SNE-2 and SNE-3 appraisal wells, and an exploration well, which will evaluate the Bellatrix prospect that lies above the northern flank of the SNE discovery. The BEL-1 exploration well will commence operations between the first and second quarter of 2016 and plans are in place to develop this well into an additional appraisal well, which will evaluate the northern part of the SNE field. At the end of the third quarter of 2015 Cairn Energy also presented, to its joint venture partners, a program and budget for three further optional wells in Senegal for 2016/2017, suggesting the country will be the subject of continued exploration for these companies in the near term.
In January of this year, Cairn Energy plc announced that it flowed oil from the SNE-2 appraisal well at a rate of around 8,000 barrels per day from one interval and 1,000 bopd from another.