Broaching Analysis – Managing Risk with Simulation and Prediction
The most catastrophic event during a drilling or workover operation is a blowout or an uncontrolled flow of formation fluids from the wellbore. Wild Well has focused its efforts to provide technology solutions that help to mitigate well control risks during the life cycle of any given well. Among those well control risks is the broaching risk. Broaching results from a venting of fluids to the surface or to the seabed through channels external to the casing.
Broaching has always been a concern to many operators while drilling, especially in shallow formations. The concern has been more focused lately on broaching during deepwater drilling operations. In the US, the Bureau of Safety and Environmental Enforcement has adopted a Well Containment Screening Tool to assess new wells' adequacy for capping and containment should a total loss of well control takes place. The geological integrity and broaching possibilities of drilled and cased formations is one of the assessment criteria to gain required permits to drill.
The goal of Wild Well's broaching analysis is to determine what geologic conditions might lead to broaching (fracturing to surface) from an underground blowout where the blowout from a deeper influx zone has broken down and is fracturing at a shallower casing seat or a shallower weaker zone. This objective is typically accomplished by building a relevant geologic model for fracture simulations and determining the "injection" rate into the zone being fractured due to outflow from the blowout zone.
The broaching simulation is an iterative process requiring several iterations to achieve an optimum solution. The iterations cover injection rate, different pore pressures, fluid loss layering, etc., to determine what geologic conditions may lead to "broaching."
For more information, read the full article Broaching Analysis, by Mo Amer.