In the years before the invention of the Sentinel Drilling Safety Float Valve (DSFV) by Drilling Innovative Solutions, the oil and gas drilling industry was employing drilling floats that were quickly becoming outdated. These floats had long carried a reputation for being faulty, unreliable, and requiring costly maintenance time. As the fluid flow is always across the sealing surface during drilling, the integrity of the sealing surface quickly becomes compromised. Fortunately, such issues have virtually become a thing of the past industry-wide, thanks in no small part to the Sentinel.
How the Sentinel DSFV Works
Unlike the standard floats of the past, the Sentinel was designed to be open during drilling or circulating operations. However, it is also designed to close when a fluid and/or gas flows back up the drill string at a rate of 3-7 gallons per minute and 7 pounds per square inch of pressure differential across the valve. Another interesting feature that sets the Sentinel apart from standard drilling floats is the actuated ball valve. This innovative aspect of the tool means that flow and differential pressure can cause the valve to close and isolate pressure and flow below the valve, with a maximum differential pressure of 10,000 psi across the valve. As a result of the engineering and build quality, the Sentinel is able to operate in 450 degrees Fahrenheit.
When the Sentinel is in the neutral flow position, there is no downward drill string fluid flow from pumping. Furthermore, there is no upward flow from wellbore formations and/or tube flow from annular overbalance. The ball position is open via spring force to allow pressure to equalize, and the spring force causes the flappers to close. The valve remains nominally open to allow the pressure to equalize, allowing bottom hole pressure to be determined with the pump off and the pipe connected.
When the Sentinel is in the open flow position, however, and pumping fluid through the drill string from the surface, the ball position is open as a result of spring force and downward fluid flow. In this position, the downward flow also forces the flappers open. This is in contradiction to the closed flow position, when differential pressure forces the ball position closed. This is a result of the back flow triggering the piloting flappers to close the valve and stop the flow up the drill string.
Advantages Over Standard Drill Floats
The reason the Sentinel was responsible for the paradigm shift in drilling safety floats was that it offered several unique and revolutionary advantages, all of which can save hours of rig time for operators, and millions of dollars as a result. Among the advantages of this new type of drill float are:
- A significantly longer service life in abrasive flow regimes
- Higher pressure capability (10,000 psi +) with elastomeric-to-metal sealing
- The ball valve used for sealing is always protected from erosion
- Valve is full-opening with minimal pressure loss
- Non-slamming
- High resistance to vibration
- Highly adaptable to a broad range of conditions
The versatility of the Sentinel is a large contributor to its impact on the industry. In any application that requires drilling floats, the Sentinel can be deployed, and it’s especially advantageous in operations requiring full-opening drill strings. The Sentinel is also versatile in that it can be deployed in both Managed Pressure Drilling (MPD) and Underbalanced Drilling (UBD) operations. The Sentinel has been successfully deployed everywhere from the Alaska North Slope, Mexico, Argentina, Brazil, the North Sea, and beyond; saving operators time, money, and carbon emissions each time.
Innovate With Us
As always, Drilling Innovative Solutions looks to create revolutionary tools and save time and money for oil and gas operators. Our engineers will continue to identify problems and potential in the oil and gas drilling industry and develop solutions that reduce rig time, emissions, and make operations safer. Keep a look out for our next innovation as we continue to assist oil and gas operators in deployments across the globe! Be sure to follow us on Facebook or LinkedIn to get updates on new tools and jobs.
