A Modern Well HAZOP Approach

Although hazard identification and risk assessment are regarded as key factors in present Gulf of Mexico regulatory environment, practical applications are not common. Limited literature exists on HAZOP for fossil fuel wells and how to approach and document properly. Recently, several custom-made techniques have been applied for hazard identification (HAZID) method for wells; however, wells project teams continue to struggle on how to apply HAZOP to their well designs.

This paper proposes a structured, comprehensive method to apply HAZOP to well design that ensures that containment, pressure isolation and well control are achieved during the drilling, completion, intervention, stimulation, and abandonment of the well. This method addresses wells’ process safety in light of the complexity of modern deepwater wells under:

—    Higher pressures and temperatures

—    Reservoir H2S content and H2 charging due to operational exposure

—    Completions add intricacy by adding perforations, packing and/or screens for sand control, down hole gauges, gas lift, gas/water injection mandrels, and even smart flow/pressure and temperature measuring arrays

—    Multiple zones of the wellbore and zonal isolation

The crucial elements of this method are to apply and customize the typical HAZOP methods for wells, including guidewords for relevant phases and containment barrier envelopes: primary, intermediate, secondary; well intervention, and contingency well control.In comparison to current practices, the authors observed that this method was a structured and comprehensive method to perform HAZOP to well design.This paper will research and compile information for a HAZOP method that can be used as best practice for process safety applied to fossil fuel wells.