The technical presentation “Evaluating Waterflood Effectiveness and Hydrocarbon Recovery Using Constraint Inversion of Resistivity Sigma and Core Data” will be given by Harish Datir from SLB.
Abstract:
Accurate monitoring of waterflood performance in carbonates is often limited by uncertainty in water saturation (Sw) estimation. Resistivity measurements are sensitive to salinity variations, while Carbon–Oxygen logging may be affected by oil-filled annuli, introducing interpretation bias.
An enhanced joint inversion of resistivity and Sigma logs applied to reduce these uncertainties. The method incorporated reservoir-specific constraints, including salinity bounds defined by connate and injected seawater, Archie’s m and n from core data, irreducible oil saturation, and matrix/oil Sigma values calibrated with core and spectroscopy data. Resistivity was interpreted using the water equation suitable for clean carbonates, while Sigma, unaffected by annular fluids, provided a stable reference for salinity. Iterative inversion reconciled both datasets, enabling refinement of salinity and Sw estimates.
The approach delivered consistent present-day Sw profiles and improved quantification of flood front advancement. Time-lapse results showed a progressive deepening of the swept interval and reduction of hydrocarbon saturation to irreducible levels, confirming effective displacement and pressure support. The workflow reduces uncertainty in dynamic saturation monitoring, improves understanding of sweep efficiency, and can be applied in comparable carbonate reservoirs to optimize waterflood management and identify bypassed hydrocarbons.
Bio:
Harish B. Datir is a Principal Domain Champion for Petrophysics, Acoustics and Geology services, based in Stavanger, Norway. He began his career with SLB in 2007 as a Wireline Field Engineer in Saudi Arabia and has held various roles across multiple locations. In 2017, he assumed his current position as Domain Champion, leveraging his experience in formation evaluation in both carbonate and clastic environments. He worked in the Middle East for five years, and since 2012, he has been working in Scandinavia, covering Norway and Denmark operations. He has a degree in applied geology and a master’s in applied geophysics. His work focuses on developing new integrated answer products and improving the existing ones in support to better utilization of SLB log measurements and to contribute to more reliable reservoir characterization.