Leaks can occur at any depth of water where a well is located, posing a risk to operations, personnel, finances and the environment. A newly developed valve technology by Deep Sea Innovations LLC can quickly close a leaking well at any depth and allow the well to be reopened at any time thereafter for further production. The financial consequences of an environmental disaster would no longer be a concern for those operating wells offshore.
This valve, called the Intensifier, is compact enough to be stored on any drilling or production rig, avoiding the wait for any specialized equipment to be shipped to a leak site, and its installation is quick and reliable. There should not be a need to conduct extensive environmental cleanups that result in the expense of drilling kill wells and subsequently drilling another production well. This valve technology is designed to change an uncontrolled risk to a finite, calculable and reasonably priced risk, providing higher coverage at lower cost.
FIGURE 1. This patent drawing shows perspective and a cross section of the valve. (Source: Drill Right Technology)
How it works
The Intensifier has only one moving part that is not connected to any other part of the valve. The valve’s simplicity of design affords a high level of reliability in performance and maintenance. The valve leverages the use of ambient water pressure to close and reopen the valve, and it has no practicable limit to the depth at which it can operate. For shallow-water sites, accumulators can be used to provide the needed force to operate the valve to close the well or reopen it.
Analysis shows how water pressure exerts force onto the sidewall of the chamber that contains the valve’s piston, which can freely move within its housing despite the external ambient water forces. The resistance to the ambient water force allows the piston to move to close and reopen the leaking well. The valve is scalable to operate at any depth and overcome wellhead pressures.
The Intensifier is shown in perspective and cross section in patent drawings in Figure 1. A valve capable of closing a leak at about 1,524 m (5,000 ft) of water would be about 48 in. wide and about 84 in. tall, weighing between 6 and 8 tons.
FIGURE 2. The Intensifier valve can be used in a variety of applications. Shown here, from left to right, are emergency response/well recovery and well capping for future production, positioned in tandem with BOP for production and as a production BOP. (Source: Drill Right Technology)
The upper portion (10) of the valve defines the sealed chamber (12), which contains a movable piston (14). The arm (16) of the piston is movable within the engagement cylinder (18). The cylinder defines vent openings (20) that are positioned symmetrically around the cylinder.
The engagement cylinder is lowered over the leaking riser. Additional weight is required to place the valve properly. The leaking oil or gas flows through the engagement cylinder and out the vents, providing stability for the engagement of the valve to the riser. The engagement cylinder at this point may be optionally secured to the riser.
In operation, a valve (22) on top of the cylinder is opened to permit either pressurized ambient water or pressurized fluid from an accumulator into the portion of the sealed chamber above the piston head (26). The pressurized fluid exerts a force onto the head of the piston, causing the arm to move downward within the cylinder, thus closing the vents and shutting off the flow of oil or gas through the Intensifier valve. A dashed line below the vents illustrates the closed position of the piston.
The valve can be reopened simply by opening a valve (30) on the upper portion of the valve and leaving the valve on the top of the Intensifier open. The pressurized fluid that enters the lower portion (28) of the chamber and the pressure of the oil or gas on the bottom of the arm (16) will move the piston upward to unblock the vents and permit the oil or gas in the well to recommence flowing through the vents.
Subsequent opening and closing of the vents can be achieved using accumulators. For example, to reclose the valve, an accumulator can be attached to the upper valve and activated while the lower valve (30) is open. To close the intensifier again, an accumulator can be attached and activated through the lower valve while the upper valve is open.
Extremely high forces can be generated by this valve. For example, a 25-in. diameter head on the piston in about 1,524 m of water will exert more than 1.1 MMlb of downward force on the piston. With a 9-in. diameter arm, a closure force in excess of 17,000 psi can be exerted against the wellhead pressure. By varying the dimensions of the valve, whatever force may be necessary to close a well can be generated.
The valve technology not only offers financial benefits by avoiding disasters but also can provide savings in E&P within the oil and gas fields of the world.