Understanding the Treatment of Low Flow Pipelines Using a Solid Time Release Product through the use of Residence Time Distribution Models

With time, many shallow gas systems experience a large decline in production. As the pipeline gathering lines have been sized for early production, flow rates are now low and liquid residence times are large. Baker Hughes has developed a new solid time-release encapsulated product for treating such systems. Residence time distribution (RTD) models were used to simulate the transport of chemicals in these low-flow systems. RTD functions are often used to understand reactant conversion in non-ideal reactors.  It is believed that their use in understanding the transport of chemicals in slow moving systems can be useful for improved corrosion control. There are many parameters that affect the deliverability, effectiveness and release control of encapsulated products in oilfield systems. One factor is the diffusion of inhibitor within the encapsulating matrix and its variance with particle size. Other factors are related to the mass transfer to an external fluid phase and the intrinsic residence time of fluids within the system. Some factors can be controlled by the design of the product while others are controlled by the system. In this presentation, the factors controlling time release properties of the product are discussed.  Laboratory results on product release are best fit to an appropriate diffusion-mass transfer model of the product. An RTD model for an existing field in Canada has been developed based on the best fit of an earlier field trial. This model, in conjunction with a model of time release of a newly developed product, has now been used to predict the new product’s time release in field application.  The predictions and the actual experimental results from the field trial will be compared with a view to using the product in different systems and achieving optimal inhibitor release profiles.