Flow dynamics during the hydrocarbon exploitation for prevention and management of water venues in oil field: A study case of Crystal field in Chad

Water management in any oil field is a challenge. This is particularly true when producer wells are drilled on a mature field, that has produced for some time and had already experienced a water breakthrough. The Crystal field is in the Doba basin at 430 km south of N’Djamena (Figure 1). The field was discovered with CRYS-01 well drilled by ExxonMobil in 2002 which proved the presence of hydrocarbons in Upper and Lower Cretaceous. From 2012, intensive drilling campaigns were conducted to develop the oil potential of the field. Two wells were drilled in 2012 and 28 wells were drilled from 2013 to 2019 including horizontal oil producers and water injector / disposal wells. The production started in 2013 and reached a peak of 15 000 bopd in December 2014 from 3 reservoirs (Figure 2): • The reservoir A (Upper cretaceous) produced by 12 wells including 10 horizontal wells. To date, the reservoir A cumulated 10.5 MMstb of oil leading to a recovery factor (RF) of 5% (OIP estimated at 192 MMstb).