Design of a Partitioning Interwell Tracer Test for a Chemical EOR Pilot Targeting the Sabriyah Mauddud Carbonate Reservoir in Kuwait

Abstract

Abstract This paper sheds light on the design of a Partitioning Interwell Tracer Test (PITT) for a normal 5-spot chemical EOR pilot targeting the Sabriyah Mauddud (SAMA) carbonate reservoir in Kuwait. This pilot is currently going through the water pre-flush phase which will be followed by chemical injection in the near future. Due to recent improvements in the synthesis of partitioning tracers, water-based partitioning tracers can now be utilized to evaluate variations in oil saturation pre and post EOR applications as well as interwell connectivity for chemical EOR pilots. A PITT is planned to take place in support of a normal 5-spot chemical EOR pilot in the SAMA reservoir. Four unique passive tracers will be injected into the pilot injectors prior to better understand reservoir conformance. This will be followed by the co-injection of four passive-partitioning tracer sets to evaluate oil saturation before and after chemical injection. A fit-for-purpose facility set-up has been installed to perform quasi-simultaneous injection of different tracer packages into the four EOR pilot injectors and a robust sampling strategy was developed to analyze the produced fluids from the pilot producer and sampling observation well in addition to other offset producers surrounding the pilot area. Periodic lab analyses involving techniques such as Gas Chromatography coupled with Mass Spectroscopy (GC-MS) will be performed to analyze tracer breakthrough times, peaks, dispersion and partitioning-passive tracer relationships. The findings from this PITT will be used to develop a comprehensive understanding of oil distribution and inter-well connectivity within the pilot area to assess the techno-economic feasibility of multi-pattern chemical EOR deployment. This PITT in a major carbonate reservoir is one of the first reported field cases to evaluate variations in oil saturation and interwell connectivity for subsurface chemical EOR applications in a normal 5-spot pattern pilot area.