Method and system for controlling tongs make-up speed and evaluating and controlling torque at the tongs
First Claim
1. A system for monitoring the torque at a set of rod tongs during a make-up process, comprising;
- rod tongs comprising an upper jaw and a back-up wrench;
a load cell positioned adjacent the back-up wrench; and
a block member capable of being in contact with the load cell, wherein the block member transmits a force from the back-up wrench to the load cell, the force generating the load signal at the load cell,wherein in response to a torque being applied to a rod held by the rod tongs, the second end of the back-up wrench moves in a first direction;
wherein the movement of the second end of the back-up wrench in the first direction causes a corresponding move of the first end of the back-up wrench in a second direction opposite the first;
wherein movement of the first end of the back-up wrench in the second direction generates a corresponding force in the block member in the second direction; and
wherein the load cell senses the force from the block member in the second direction and generates a torque signal.
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Accused Products
Abstract
Make-up speed for a tongs drive system is monitored and controlled to maintain the speed within a limited target range either throughout the make-up process or during the final portion of the make-up process, thereby improving make-up consistency and allowing for improved evaluation or torque during the make-up process. An encoder generates speed and position data during the make-up process. The speed data is compared to a target speed, which is based on rod and/or tongs characteristics. If the speed does not match the target speed or is not within a range of the target speed, a signal is transmitted to the tongs drive to adjust the speed accordingly. Furthermore, position data from the encoder, or other position sensors, provide position data for the rod during the make-up process to limit or vary the speed control parameters during different portions of the make-up process.
71 Citations
14 Claims
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1. A system for monitoring the torque at a set of rod tongs during a make-up process, comprising;
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rod tongs comprising an upper jaw and a back-up wrench; a load cell positioned adjacent the back-up wrench; and a block member capable of being in contact with the load cell, wherein the block member transmits a force from the back-up wrench to the load cell, the force generating the load signal at the load cell, wherein in response to a torque being applied to a rod held by the rod tongs, the second end of the back-up wrench moves in a first direction; wherein the movement of the second end of the back-up wrench in the first direction causes a corresponding move of the first end of the back-up wrench in a second direction opposite the first; wherein movement of the first end of the back-up wrench in the second direction generates a corresponding force in the block member in the second direction; and wherein the load cell senses the force from the block member in the second direction and generates a torque signal. - View Dependent Claims (2, 3, 4, 5)
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6. A method of evaluating a torque signal from a set of tongs comprising a tong drive, the tong drive comprising a set of upper jaws and a back-up wrench, the method comprising the steps of:
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accepting at a processor a high torque limit for a rod make-up process; accepting at the processor a predetermined amount of time; conducting the make-up process of a rod and a coupling with the tongs by applying with the upper jaws a torque on the rod; applying with the upper jaws a torque on the rod; receiving a torque signal from a load cell representing an actual torque; determining with a processor if the actual torque is greater than the high torque limit; determining with the processor if the actual torque is greater than the high torque limit for a time period equal to or longer than the predetermined amount of time based on a positive determination that the actual torque is greater than the high torque limit; and automatically stalling the tong drive in response to a positive determination by the processor that the actual torque is greater than the high torque for a time period equal to or longer than the predetermined amount of time. - View Dependent Claims (7, 8, 9, 10, 11, 12, 13, 14)
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Specification