US 6,212,763 B1Granted

Torque-turn system for a three-element sucker rod joint

OwnerFrederic M. Newmaninventor

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Abstract

A sucker rod tool system for oil wells monitors both torque and angular displacement of a three-element sucker rod connection. The tool system engages two sucker rods that are at least partially screwed into opposite ends of a sucker rod coupling. The system, however, does not engage the coupling adjoining both rods. The system determines whether a connection has been properly tightened by sensing the torque and angular displacement of the connection as it is being tightened, and comparing the data to a stored reference set of data or curves. In some embodiments, a properly tightened connection is based upon the number of straight lines that are needed to adequately approximate a plotted curve of the sensed torque versus angular displacement. Tightness of each connection of a string of sucker rods is recorded with reference to each connection's depth within a well to later serve as an aide in diagnosing connection failures. In some cases, the energy required to unscrew a connection is also recorded. In some embodiments, the system automatically determines whether one or both sucker rods of a three-element connection need to be tightened.

Claims14

Dependent claims

A sucker rod tool system adapted to simultaneously torque two threaded joints of a three-element connection, wherein said three-element connection includes a first sucker rod and a second sucker rod screwed into opposite ends of a threaded coupling, wherein said first sucker rod includes a first set of flats and a first shoulder and said second sucker rod includes a second set of flats and a second shoulder with said first shoulder and said second shoulder being adapted to abut said opposite ends of said threaded coupling upon said three-element connection being tightened, said sucker rod tool system comprising:

a rod tongs having a first set of jaws adapted to engage said first set of flats of said first sucker rod and a second set of jaws adapted to engage said second set of flats of said second sucker rod while said threaded coupling threadingly engages said first sucker rod and said second sucker rod;
a drive unit coupled to rotate said second set of jaws relative to said first set of jaws, thereby applying a torque simultaneously to said first sucker rod and said second sucker rod with said threaded coupling interposed therebetween;
a first transducer adapted to provide a first feedback signal measuring an angular displacement of said first set of jaws relative to said second set of jaws;
a second transducer adapted to provide a second feedback signal that varies as a function of said torque applied to said first sucker rod and said second sucker rod;
and
a control responsive to said first feedback signal and said second feedback signal to help determine an extent to which said drive unit rotates said second set of jaws relative to said first set of jaws, thereby verifying a predetermined acceptable tightness between said first sucker rod and said threaded coupling and between said second sucker rod and said threaded coupling.

3 more elements

Dependencies are inferred from the claim text.

Facts

Application: 09/342,564Filed 29 Jun 1999
Granted: 10 Apr 2001
Term ends: Not estimatedThe source records don’t support an estimate.

Classification13 codes

E21B 19/166
Control or monitoring arrangements therefor: arrangements of torque limiters or torque indicators
B25B 21/002
Portable power-driven screw or nut setting or loosening tools; ; Attachments for drilling apparatus serving the same purpose: for special purposes
B25B 23/14
Details of, or accessories for, spanners, wrenches, screwdrivers: arrangement of torque limiters or torque indicators in wrenches or screwdrivers
B25B 23/145
Arrangement of torque limiters or torque indicators in wrenches or screwdrivers: specially adapted for fluid operated wrenches or screwdrivers