Engineered fabricated coil-tube assemblies are often used in upstream downhole applications as a cost- and time-effective way to provide well intervention solutions. Operations such as cleanout as well as heat exchanger, electronics and pressure controls can be efficiently performed with fabricated coil-tube assemblies.
Nitrogen coils comprise one type of coiled tubing assembly used in exploration as a heat exchanger to remove heat in high-temperature applications and/or control pressure to open and close a valve. High pressure and high temperature are huge challenges to the oil exploration industry. Such coils are used to regulate differential pressures to help close "flapper springs" on subsurface safety valves in deep well applications.
When a valve is used to regulate the flow of natural gas or crude oil, a safety valve is necessary. The flammable nature of what flows through the tubing requires precise and rugged manufacturing. For example, during Operation Desert Storm, the Kuwaiti oil fields caught fire when Iraqi soldiers blew off wellheads, the component at the surface of an oil well with the structural and pressure-containing interface for drilling and production equipment. The wellheads had no subsurface safety valves; if equipped, the oil would have automatically stopped flowing, and an enormous amount of environmental damage could have been avoided. Today, nitrogen coils are used to control pressures of (open/close) valves and prevent such disasters from occurring.
The tubing varies in length from deep to shallow wells, depending on whether the application is for natural gas or crude oil. The amount of well pressure put onto the valve is determined by the nitrogen coil. Deep drilling results in higher temperatures, and companies are drilling increasingly further into the earth. Currently, Engineered Spring Products® (ESP), a division of MW Industries Inc., is manufacturing a high-pressure application rated at greater than 40,000 psi. That's the type of challenge customers often ask for help with: obtaining nitrogen coils that can handle more pressure and more heat transfer than older designs.
Other challenges pertain to getting information from the drilled bore itself. Electronic extender tube-coiled springs are used by drilling companies as a communication link between two instrumentation housings in the drill string for the sampling process to take measurements while drilling (MWD). Customers use MWD to evaluate the production value of the reservoir during and after drilling.
Wire is fed through the coiled body, which acts as a spring that connects the housings. This extender spring stabilizes the tool string and allows it to compress and extend in both directions. Again, this type of device must withstand high pressure and temperature. ESP's device is safe up to 35,000 psi, and the manufacturer is redesigning it to withstand more than 40,000 psi.
ESP's electronic extender tube-coiled spring gets real-time data to operators on the surface in minutes. Prior to this component design, it would take up to weeks to get the same information.
New technology has allowed downhole drilling to reduce downtime and increase output. The more uptime drillers have, the greater their output. And more output means greater profits.
For more information, visit www.mw-ind.com/brands/engi neered-spring-products.