Churchill Drilling Tools has announced that its downhole bypass tool DAV MX CircSub made a major contribution to a recent managed pressure drilling (MPD) run in the North Sea.
In April 2018, the circulating sub was activated on an MPD completions run for a North Sea operator. Requirements were for a tool with the resilience to withstand significant differential pressure and acid breakers; the contingency capability to combat losses; and the versatility to boost displacements and drain the pipe while pulling out of hole to cut operating time.
The operator ran 200 bbl of acid breaker fluid through the tool to break the filter cake. Designed to withstand differential pressures of 10,000 psi, the DAV MX withstood the 5,000 psi required to set the completions hanger.
The operator anticipated a high risk of losses during this campaign and, therefore, required a tool that was flexible enough to provide 100% bypass to pump lost circulation material to cure losses at depths of 13,000 ft. Without the DAV MX in its string, the operator would have pumped lost circulation material down the annulus from surface, a more time-consuming and expensive process.
At the end of the completions run, the operator used the tool to boost circulation rates, cutting operating time when displacing from oil-based mud to calcium bromide brine fluid. Finally, enabling the DAV MX’s uniquely robust lock open feature, the operator was able to drain the pipe while pulling out.
The DAV MX’s emergency shut off dart (ESD) was not deployed but formed part of the operator’s decision-making process. In the unlikely event that the tool incurred acid damage, deploying the ESD would have enabled the operator to complete the run and save an extra trip to replace the tool.
Stewart Macindoe, Sales Director at Churchill Drilling Tools, said, “We’re pleased our award-winning DAV MX CircSub continues to help operators drill faster, more efficiently and at low risk. This recent North Sea completions run adds to our strong track record and growing operator demand for the DAV MX across a wide range of applications including: coring; deviated, tapered and extended reach drilling; well bore clean up; completions and plug & abandonment.”