Patent attributes
Downhole mechanical or electrical equipment that possess, induce or supply large electromagnetic interference or magnetic fields are sometimes placed in subterranean wells, usually as part of or attached to wellbore tubulars. These magnetic fields can interfere with the efficient operation of some electronic, gyroscopic or magnetic well tools that pass by, through, near or adjacent to such downhole equipment. In general, a subterranean magnetic field protective shield apparatus is provided which reduces or substantially eliminates this magnetic field interference or enhances the operation of, or minimizes damage to, sensitive electronic or magnetic well tools. Such a subterranean magnetic field protective shield enhances the operation of other tools and protects other devices from adverse effects of magnetic fields stronger than the earth's magnetic field intensity.
