This paper describes the production assurance strategy adopted to resolve scaling deposition in hydraulically fractured wellbores by means of incorporating a ceramic proppant infused with a controlled release scale inhibitor in the primary completion. This chemical delivery system has been applied as an integral component in the offshore field development program and yielded positive results.

Production assurance and scale inhibition chemicals are traditionally injected via a dedicated capillary in the production string, but this approach is often not very efficient or effective as a prevention strategy due to the uncertainty surrounding the severity and timing of the phenomenon. Contributing factors to the scale deposition include variations in the water production rate, water breakthrough from water flooding and changes in the bottom hole flowing pressure and temperature. These variable conditions also complicate the scaling prediction efforts. A ceramic proppant based chemical delivery system was selected to ensure multiyear inhibition of scale with a onetime treatment. The engineered ceramic proppant provides effective chemical delivery, high fracture conductivity and strength so it can be used to replace part of the proppant in hydraulic fracturing and frac pack completions or be incorporated into a gravel pack completion.

The strategy was successfully applied in a field in West Africa. Significant learnings from this implementation of controlled release scale technology in the primary completion was realized. The controlled release of the scale-inhibiting chemical into the production stream as it flows through the proppant pack effectively prevents scaling in the fracture, the wellbore, and completion string to surface. The key concept was to eliminate the uncertainty surrounding the onset of the scaling problems, which inevitably results during well selection process due to the variation in water production and chemistry among the wells. Another important goal was to also reduce the frequency of costly interventions in an offshore operating environment and to maximize well and field production uptime. The field application of this delivery system has successfully eased the operational challenges being observed in offset wells which otherwise require repeated treatments of scale inhibitor. Operational benefits resulted from the increased free space on the platform and eliminated any need of well interventions for remedial scale control on these treated wells.

The information presented in this paper will benefit production engineers facing similar scale and production challenges and seeking a comprehensive production assurance strategy and desire a cost-effective solution. The application of infused scale inhibitor proppant has shown to provide production assurance as a onetime treatment, regardless of well type, and can provide a sustained multi-year scale prevention solution.

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