The SNE-2 appraisal well has completed drilling and evaluation and has delivered a positive result after being safely drilled, cored, logged and flow tested ahead of schedule.
Oil flows from drill stem testing (DST) are important in demonstrating SNE is a world class oil discovery with the ability to flow oil at commercially viable rates: A DST of the lower reservoir unit flowed oil at a constrained rate of 8000 bopd (stabilised) confirming high primary reservoir deliverability.
A DST of the upper ‘heterolithic’ reservoir unit flowed oil at a maximum rate of ~1000 bopd (unstable), highlighting the potential for these upper units to make a material contribution to SNE resource and production volumes.
New SNE-2 data, plus analysis of new and reprocessed seismic and well data, and further appraisal activity is expected to lead to a future revision of the SNE field resource estimates.
Preliminary results from SNE-2
A drill stem test (DST) of a lower principal oil reservoir unit over a 12m interval (~11.5 m net) flowed oil at a maximum stabilised constrained rate of ~8000 bopd on a 48/64 in. choke. The interpreted unconstrained flow rate of this interval is greater than the testing equipment capacity of 10 000 bopd. This result confirms the high deliverability of the principal SNE reservoir units.
A DST of a shallower ‘heterolithic’ reservoir unit over a 15m interval (~3.5m net) flowed oil at a maximum rate of ~1000 bopd on a 24/64 in. choke. The flow from this interval was unstable due to the 4.5 in. DST tubing, however, this result confirms the potential of the ‘heterolithic’ reservoir units to produce at viable rates and make a material contribution to SNE oil resource and production volumes SNE-2 appears to have the same high quality 32 degree API oil seen in SNE-1.
Gas-Oil and Oil-Water depths have been confirmed, showing a similar oil-down-to and oil–up-to depth at SNE-2 of 103 m gross (SNE-1 is 96 m gross).
SNE-2 has confirmed the correlation of the principal reservoir units between SNE-1 and SNE-2 and the potential for lateral reservoir continuity.
A total of 216 m of continuous core (100% recovery) was recovered across the entire SNE field reservoir interval.
The SNE-2 appraisal well is now being plugged and abandoned and the Ocean Rig Athena will then move 6 km south to drill the SNE-3 appraisal well to evaluate the SNE oil field reservoir quality and continuity at a more southerly location.
SNE-2 is the first appraisal well in a three-well, back-to-backdrilling program designed to comprehensively evaluate the SNE oilfield from the drilling of the SNE-2 and SNE-3 appraisal wells and Bellatrix exploration well.
SNE-2 is located 3 km north of the SNE-1 oilfield discovery well and it has been drilled in 1200 m of water approximately 100 km offshore Senegal in the Sangomar Offshore block.
Adapted from a press release by Louise Mulhall
Read the article online at: https://www.oilfieldtechnology.com/drilling-and-production/06012016/senegal-drilling-update-sne-2-delivers-a-successful-appraisal-well/