Challenge: Obtain field-wide information to optimize waterflood and find bypassed pay in channel and sheet sand reservoirs of Gudao field.
Solution: Conduct three surveys with DeepLook-EM crosswell electromagnetic imaging service to track fluid displacement within the mature waterflood area.
Result: Characterized the interwell sand-shale formations and identified a bypassed oil zone that is now being produced.
Understanding a challenging environment
Gudao field in central China is a challenging production environment. The reservoirs are in both discrete channels and continuous deltaic sheet sands within an anticlinal trap. Waterflooding has been most effective in Zones 3 and 4, which are well-defined, continuous deltaic sands that range in thickness from 4 to 12 m [13 to 29 ft]. Recovery has not been as successful from Zone 5, which is less continuous and contains heavier oil. A cyclic steaming strategy has achieved some success in Zone 5