The present disclosure relates generally wellbore operations and, more particularly, to magnetostrictive power supplies for bottom hole assemblies with rotation-resistant housings.
Power for use in a downhole environment generally has been either stored in a device, such as a battery, and conveyed downhole, or it has been transmitted via conductors, such as a wireline, from another remote location. More common as of late is the use of vane turbines in the mud flow which use magnets and stator windings to generator power.
As is well known, batteries have the capability of storing only a finite amount of power and have environmental limits, such as temperature, on their use. Additionally, batteries are not readily recharged downhole. And vane turbines are subject to wear and lock up in the event of unfavorable debris in the flow.
Electrical conductors, such as those in a conventional steering tools where a cable is run on the outside of the drill pipe and enters the bottom hole assembly through a side wall port to power the down hole equipment, provide a practically unlimited amount of power, but require special facilities at the surface for deployment and typically have depth limitations and the drill string can not be rotated etc. while the conductors are in the flowpath.
In wellbore operations, a wide variety of mechanical devices are used that convert electrical power to mechanical energy in order to perform work downhole. Those mechanical devices may be subject to a variety of forces, and much of the mechanical energy may be directed to the performance of that work, while some of the energy may be released in secondary ways. What is needed is a method of harvesting mechanical energy downhole and generating electrical power therefrom.
While embodiments of this disclosure have been depicted and described and are defined by reference to exemplary embodiments of the disclosure, such references do not imply a limitation on the disclosure, and no such limitation is to be inferred. The subject matter disclosed is capable of considerable modification, alteration, and equivalents in form and function, as will occur to those skilled in the pertinent art and having the benefit of this disclosure. The depicted and described embodiments of this disclosure are examples only, and not exhaustive of the scope of the disclosure.