Cross section well pair showing temperature profiling using oil plus’s souring model.
Reservoir souring predictive modelling allows operator to reduce capital and operating costs – offshore new field development
An operator was considering water injection to increase seep efficiency in secondary oil recovery for a new offshore deep-water field. Analysis of the water composition, obtained during initial well testing, indicated the field waters contained significant sulphates and short-chain carbon-containing VFAs, as well as nitrates. Laboratory tests. There was a likelihood of H2S generation and subsequent breakthrough at the producer wellheads.
Computer modelling using a 2-D finite difference flow simulator, was used to predict the reservoir souring potential for a single injector/producer well pair in each reservoir. The model incorporated the results of two laboratory test programmes for H2S generation and reservoir scavenging capacity conducted by Oil Plus:
The model provided worse case scenarios for H2S production, allowing the client to select materials resistant to H2S concentrations of up to 70ppm. Based on the results, the client was able to keep operational costs to a minimum by dosing a biocide and H2S scavenger to protect the process facilities against the risk of corrosion caused by the presence of H2S. By factoring reservoir souring into the design of the plant, this provided the client with and estimated ROI of the study of $100.4m