Abstract
In layered carbonate reservoirs where high permeability streaks are present, it becomes challenging to keep track of injected water front movement. Pulsed Neutron Capture (PNC) surveys, in addition to other surveillance programs, served as a valuable tool to characterize premature water breakthrough in these heterogeneous reservoirs.
In this field, in many observation wells, time lapsed PNC log-interpretations have effectively been used to detect water encroachment in high permeability sub-zones. Time lapsed results also helped in developing a few type-logs, which show water front advancement in different sub-zones of various regions.
PNC interpretation results revealed behind casing water communication in certain wells. The findings assisted in carrying out reservoir management decisions.
PNC-log results were integrated with data obtained from Cores, PLT, and RPT to understand and identify water movement in different layers of the reservoirs. Water encroachment detected in different layers was also compared with the water saturation estimated in the layers based on simulation study.
