In an April 4 update, Oil Search said its first of two North Slope wells and their sidetracks this winter was a resounding success. The Pikka B/Pikka B ST1 appraisal well flowed at a stabilized rate of 2,410 barrels of oil per day, its flow restricted by the capacity of the testing equipment. (In a presentation on Feb. 18, Oil Search said the well "has intersected the thickest Nanushuk reservoir seen in the field,")
The Pikka B ST1 was spud Jan. 23 at the southern end of the Pikka unit, its target the Cretaceous Brookian Nanushuk formation with the objective to assist defining potential resource volumes and reservoir deliverability in the unit.
All coring, wireline and pressure data acquisition was completed and on March 5, a well test commenced in the 71-degree angle wellbore over a single stage stimulation in the Nanushuk reservoir. The flow test included cleanup, low flow rate and pressure build-up periods, prior to the final flow, with the test concluded on March 19.
The final flow test was conducted over a two-hour period with a flowing bottom hole pressure of 1,270 psi and flowing well head pressure of 240 psi on natural flow with no artificial lift. Based on the productivity index calculated during the final flow test, the well flow rate potential is estimated at approximately 3,800 bopd at a flowing well head pressure of 50 psi.
The objective of the second well, the Pikka C/Pikka C ST1, in the central part of the unit was to reduce uncertainty on well deliverability and test the northern extent of the Nanushuk reservoir trend.
During March, logging-while-drilling data was successfully acquired over Pikka C ST1. A flow test program began on March 14, which included testing of six stimulation stages within the 3,800-foot-long horizontal section.
Mechanical problems with the test equipment delayed starting of the test and down-hole blockages restricted flow rates and the ability to clean the well out properly. Despite the down-hole restrictions, stabilized rates of more than 860 bopd were established at 800 psi flowing bottom-hole pressure, with higher peak rates recorded during unloading the well. In addition, modelling of the geological properties recorded in the well indicate the potential for much higher flow rates than observed. While unlikely to be indicative of the full potential of the well, the test data, combined with the comprehensive data suite acquired, will be fully evaluated and integrated into the forward planning ahead of the FEED decision for the first Pikka unit development project.
Oil Search has previously said it expects a FEED, or front-end engineering and design, commitment for the Pikka project by mid-2019, subject to appraisal and an Environmental Impact Statement, or EIS, Record of Decision from the U.S. Army Corps of Engineers.
Demobilization of the Doyon Arctic Fox and Nabors 105E rigs and personnel on the wells was expected to be completed by mid-April.
- KAY CASHMAN
See story in April 14 issue of Petroleum News, available online Friday, April 12, at www.PetroleumNews.com.
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