Operators benefit from valve resilience in hostile P&A environments
HOUSTON -- Churchill Drilling Tools, an oilfield service company specializing in drilling innovation, continues to report growing demand, despite the global reduction in drilling operations, for its tools and in particular its flagship product, the dart activated DAV MX CircSub.
Operators are increasingly recognizing the value the tool delivers with Churchill reporting a 6% increase in activations in 2017, and growing demand for the tool on P&A campaigns.
The tool's resilience, which combined with its versatility, speed and reliability are enabling clients to cut operating time, was put to the test by a North Sea operator on a recent P&A campaign.
In hostile swarf-filled conditions, the operator activated one DAV MX CircSub four times across four separate runs, representing a first for the tool. The tool has been activated extensively across challenging swarf environments, however, in previous instances it hasn’t been necessary for operators to take advantage of the tool’s multi-cycle capability.
The overall pre-planned project was to section mill and cement a 7-in. liner across multiple zones. In addition to hole cleaning and removing swarf from the annular space, using the tool and its unique ‘Lock Open’ feature, the operator had 100% mill bypass control capability allowing the string to self-fill and drain while tripping in and out of the well. This meant faster, cleaner and more controlled tripping, and therefore reduced operating time.
The 100% bypass also enabled the operator to displace and condition fluids and boost annular velocity protecting the milling assembly and its cutting knives.
In this instance, the operator had a greater margin for risk-taking because of the tool’s Emergency Shut-Off Dart (ESD), a unique fail-safe feature used on the rare occasions the valve becomes damaged by swarf or an unexpected event. This toolcan be repaired in-hole. Knowing the ESD could seal any leak paths, maintain thru-bore and allow the campaign to continue without pulling out of hole encouraged the operator to push the boundaries and test the tool's resilience to the maximum.
