ADX Energy Limited, the operator of the Chorbane license, Tunisia, has advised that the testing operations at the Sidi Dhaher well have now been completed. Despite good flow rates from the two reservoir zones and substantial amounts of fluids being produced from the upper reservoir zone, the fluids were not observed to contain any quantities of oil.
Following the drilling out of the safety plug within the previously suspended well, two separate intervals within the Bireno Formation have been perforated and flow tested. A 5 meter section within the deeper Bireno Dolomite interval was perforated between 3,852-3,868 feet (1,174-1,179 meters) Measured Depth ("MD") together with a 16 meter section in the shallower Bireno Limestone interval between 3,789-3,842 feet (1,155-1,171 meters) MD.
Approximately 90 barrels of fluid were recovered which were identified as most likely consisting of a mixture of drilling mud filtrate and possibly formation water. The efficient recovery of these fluids during the test suggests that they were sourced from the deeper Dolomite interval. Although a large volume of fluids have been lost to the formation while drilling and in preparation for the test, and the total volume had not yet been recovered during the flow test, the Joint Venture participants agreed to plug off the deeper Bireno Dolomite section and test only the shallower Bireno Limestone section in isolation.
After performing a cement squeeze to close the perforations over the deeper Bireno Dolomite interval, and the setting of a bridge plug within the well-bore and between the Bireno Dolomite and the Bireno Limestone intervals, a flow test of the Bireno Limestone interval commenced. Prior to acid stimulation of the reservoir, no liquid flow from the Bireno Limestone was observed and an acid stimulation was undertaken.
Following completion of the acid stimulation, the well was flow tested, with the benefit of nitrogen lift and approximately 680 barrels of fluid were recovered over a flow test period of 35 hours. The initial interpretation from the well site is that the recovered fluid is a mixture of spent acid, drilling mud filtrate and formation water.
The well will now be plugged and abandoned, and the drilling information and test data will be interpreted before determining any further operations to be undertaken on the Sidi Dhaher structure.
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