The well, drilled by the ENSCO 70 jackup 1.8 km (1.2 mi) northeast of the Breagh Alpha platform, intersected 112 ft (34 m) of net pay in four separate zones. The Schlumberger well stimulation vessel Big Orange XVIII, working in tandem with the rig, conducted hydraulic stimulations over two of the four sands encountered within the main productive area.
Previously these zones were thought to be of lower reservoir quality than the other two zones and so viewed as suitable for stimulation to boost the well’s production potential. Sterling says 300,000 lb of proppant was pumped in, following which the well was flow tested at 25 MMcf/d (707,921 cm/d) in conditions 500 psi (34.4 bar) higher than the current platform export pressure.
In contrast, one of these intervals flowed at 4 MMcf/d (113,267 cm/d) in the offset A05 well.
Further perforations followed over these stimulated intervals and the remaining two sands that had not been stimulated. A final combined flow rate of 44 MMcf/d (1.2 MMcm/d) was then achieved at flowing conditions 400 psi (27.6 bar) higher than the current platform export pressure. Sterling estimates the unconstrained rate at 55-60 MMcf/d 1.6-1.7 MMcm/d).
A08 is expected to enter production in mid-November delivering 42 MMcf/d (1.18 MMcm/d) of sales gas and 140 b/d of condensate.
“We have achieved another very successful hydraulic stimulation in this well, achieving rates from the middle two zones which are at least three times what would have been expected from a normal completion and with a much higher producing pressure,” said John Rapach, Sterling’s COO. “Our expectation is that we will be able to sustain production at the tested rate for an extended period, as the well is opened-up to lower the back pressure on the reservoir. In addition, the hydraulic stimulation should lead to incremental reserves from these stimulated intervals."
CEO Jake Ulrich said: “We look forward to returning to the Breagh Alpha platform for further drilling and stimulations during 2015.”
ENSCO 70 will next drill the Crosgan appraisal well in block 42/15, 25 km (15.6 mi) northeast of Breagh. Sterling Resources has a 30% in the Breagh and Crosgan license areas. RWE Dea UK has a 70% operated stake in both licenses.