Gulf Keystone commenced workover operations on well HEK-3, an oil and gas discovery well drilled by SONATRACH in 2004. At that time, the well was tested over the Cretaceous, Coniacian limestone interval and achieved, post acidisation, flow of 184 barrels of oil over a 4 hour period, prior to the well being suspended.
Gulf Keystone re-entered the well and tested the same zone, over the measured interval 2,439 to 2,446 metres, employing an acid fracturing technique to improve connectivity between the reservoir and the wellbore. After cleaning up the well, a stabilised flow rate of 1,040 barrels per day of 31 degrees API oil was achieved through a 32/64 inch choke. The well was flowed through a separator for a total of 4.5 days and over 3,500 barrels of oil were produced during this period. The crude contained little entrained gas and has an estimated gas/oil ratio of 93 scf/bbl. The well is presently suspended with a pressure gauge in the hole. This will be retrieved in 3-4 weeks to obtain the pressure data.
A large amount of good quality engineering data was collected during the test programme which, combined with the produced volume of oil and the long flow and shut in periods, will provide valuable data for reservoir evaluation and field development study purposes. Production optimisation studies will be carried out to analyse options for further increasing well productivity with a view to the possible early development of this discovery, subject to necessary consents. In this regard, consideration will be given to pump and/or gas lift options to further improve both the rate and delivery pressure of the well.