Hydrogen Sulfide Forecasting Techniques for the Kuparuk River Field

Abstract

ABSTRACT This is a case study on developing hydrogen sulfide (H2S) forecasting techniques for the Kuparuk River Field. Initial oil production from the field was sweet. However, the field is currently souring while undergoing recovery from a combination of waterflood and water alternating immiscible gas injection. Evidence of microbiological souring and discussion on the evolution of H2S forecasting techniques are provided. The evolution of H2S forecasting techniques involved: 1) developing an initial forecasting model, 2) investigating H2S data on a well and field basis, and 3) altering the initial forecasting model to keep it consistent with H2S data. This work resulted in a model that is consistent with field data. These data indicate that at produced water sulfate concentrations ≥250 ppm, H2S production is independent of sulfate availability and averages approximately seven pounds per thousand barrels of water. Furthermore, these data suggest that H2S that is being reinjected into the reservoir is either being removed (stripped by reservoir fluids and/or scavenged by iron bearing minerals) or reducing H2S generation.