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US 5,512,889 AGranted
Downhole instruments for well operations
AssigneeAtlantic Richfield Company
InventorPaul A. Fletcher
Life of this patent
Estimating the term…
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AssigneeAtlantic Richfield Company
InventorPaul A. Fletcher
Estimating the term…
Pressure and temperature signals are transmitted between a predetermined point in a wellbore and the earth's surface by an electromagnetic wave transmitter disposed in the well and connected to a bow-spring centralizer forming one contactor of a dipole and a mandrel or hanger connected to a landing nipple of a tubing string in the well whereby the other conductive path forming the other end of the dipole may be formed by a packer or similar mechanism in conductive engagement with the tubing string and the well casing. The hanger may be a lock mandrel or a suitable conventional downhole tool hanger. The electromagnetic wave transmitter may be deployed in the well and engaged with the casing by spaced-apart magnets to establish the conductive path and the dipole distance. The transmitter may also be deployed on and connected to coilable tubing which has an insulative coating on the exterior surface for a predetermined length to prevent short-circuiting the conductive path by engagement of the coilable tubing with the casing wall, for example.
In an arrangement for a downhole instrument for transmitting data to the surface from a well, said well having a casing extending through an earth formation, said well having perforating means in said casing in communication with a predetermined zone of said earth formation, a signal transmitting device interposed in said well, comprising at least one sensor for sensing a condition in a portion of the wellbore of said well and a signal transmitter for transmitting information related to said condition to the earth's surface, a contactor connected to said device and engaged with said casing at one point, a tubing extending within said well for positioning said devices and a mandrel engaged with a landing nipple connected to said tubing for locking said device in a predetermined position in said well and for providing an electrically conductive path between said device and said casing at a predetermined distance from said contactor for establishing a dipole for the generation of electromagnetic waves in the earth by said device.
In an operation for substantially real-time monitoring of at least one of pressure and temperature in a predetermined portion of a wellbore of a well extending within the earth, the improvement characterized by:
In an arrangement for a downhole instrument for transmitting data from a well, said well having a casing extending through an earth formation and perforation means in said casing in communication with a predetermined zone of said earth formation,
In an operation for substantially real-time monitoring of at least one of pressure and temperature in a predetermined portion of a wellbore of a well extending within the earth, the improvement characterized by:
In an arrangement for a downhole instrument for transmitting data to the surface from a well, said well having a casing extending through an earth formation and perforation means in said casing in communication with a predetermined zone of said earth formation, a signal transmitting device interposed in said well comprising:
Dependencies are inferred from the claim text.