BACKGROUND OF THE INVENTION

1. Field of Invention

The present disclosure relates to an assembly for use with transferring sucker rods, and that includes a means for biasing a safety ring into a retaining configuration.

2. Description of Prior Art

Most wells that produce fluids from subterranean formations typically rely on pressure in the formation to lift liquids upwards within the well to surface. In some of these wells formation pressure is insufficient to lift the liquids in the well to surface; which is sometimes the case initially, or in some instances occurs over time as the formation fluids become depleted. Artificial lift systems for unloading liquids from a well include pumps, such as electrical submersible pumps (“ESP”), which pressurize the liquid downhole and propel it up production tubing that carries the pressurized fluid to surface. Plunger lift pumps are also sometimes employed for lifting liquid from a well, which are usually operated by a reciprocating pump jack that is disposed on surface. A string of sucker rods deployed in the well usually attaches to the pump jack, and that transmits a force from the pump jack to the lift pump.

Sucker rods are elongated members with lengths that generally range from 25 feet to 30 feet, and with diameters from about 0.5 inches to in excess of one inch. Sucker rods are typically formed from carbon steel with varying amounts of manganese, phosphorus, sulfur, silicon, nickel, chromium, and molybdenum. As a result of their size and relatively dense materials, some sucker rods weigh in excess of 100 pounds. Due to their sometimes unwieldy weight, sucker rod transfers are used to handle sucker rods, such as when being unloaded from transport vehicles proximate a well. Sucker rod transfers are typically annular members that are suspended by a cable, and fitted with a slot on its lower end; most sucker rods have a wrench flat proximate an end that inserts into the slot, and which couples the sucker rod transfer with the sucker rod. Some sucker rod transfers include safety rings that are slid into place to retain the sucker rod end inside the transfer. These rings rely on gravity to remain in place and may be moved out of place inadvertently. Which could allow the sucker rod to fall from the transfer and result in property damage or personal injury.

SUMMARY OF THE INVENTION

Described herein is an example of a sucker rod transfer assembly that includes a body, a cavity in the body that selectively receives an end of a sucker rod, a safety ring that is slideable along an outer surface of the body and between, a retracted position that is spaced away from the end of the sucker rod, and a deployed position that is radially adjacent the end of the sucker rod, and a spring that circumscribes the outer surface of the body and that is in biasing contact with the safety ring. In an example, the spring has a spring index of at least around 30 and in an alternative has a spring force of less than 10 pounds force. The sucker rod transfer assembly further optionally includes a spring retaining ring mounted to an end of the body; which in an embodiment includes a frusto-conical crown on one end, a base on an opposite end, and a reduced diameter portion between the crown and base that defines a recess in which the spring disposed. In an example, a slot is formed radially through the base. An optional opening is included in the body that extends along a length of the body and that provides access to the cavity. In an embodiment an axial end of the spring is in contact with the safety ring along the full circumference of the safety ring.

Also disclosed is a method of transferring a sucker rod, and that includes obtaining a sucker rod transfer assembly that is made up of, an elongated body, a cavity in the body, an opening along a length of the body in communication with the cavity, a safety ring on an outer surface of the body, and a spring in biasing contact with the safety ring. The method of this example also includes manually sliding the safety ring along the length of the body to compress the spring, inserting an end of a sucker rod into the cavity through the opening, and releasing the safety ring so that the safety ring is moved into a deployed position that circumscribes a portion of the sucker rod and is in interfering contact with movement of the end of the sucker rod from within the cavity through the opening. The spring optionally has a spring index of at least 30 and in an alternative has a spring constant of around 10 lbf/in. In one example, the method further includes lifting the transfer assembly and sucker rod from a transport vehicle to a rack disposed proximate a well; and also optionally includes installing the sucker rod into a string of sucker rods mounted in the well, reciprocating the string of sucker rods to lift fluid from within the well. In an alternative, the spring is in sliding contact with the outer surface of the body.

Another example of a sucker rod transfer assembly is disclosed and that includes an elongated body having, a curved outer surface, an inner cavity, a lengthwise axis, sidewalls that span a length of the body and that extend around a portion of the axis circumference to define spaced apart radial surfaces, an opening between the spaced apart radial surfaces that defines an access to the cavity, a base formed on an axial end of the sidewalls and extends radially inward from the sidewalls, a slot in the base, a shoulder formed on a portion of the base that extends radially past an outer circumference of the sidewalls, and a recess formed longitudinally along an outer surface of the sidewalls. Also included with the transfer assembly is a safety ring that circumscribes the axis and is slideable along the outer surface of the sidewalls and a spring in close contact with the outer surface of the sidewalls and that biases the safety ring towards the base. In an alternative, a crown is provided on an axial end of the sidewalls opposite from the base and a spring retaining ring circumscribing the crown, wherein an axial end of the spring distal from the safety ring abuts a lateral surface of the spring retaining ring. In an embodiment an outer diameter of the crown exceeds an inner diameter of the spring. In this example, the cavity selectively receives an end of a sucker rod, wherein the spring exerts a resistive force of up to about 10 pounds-force against the safety ring in response to a manually applied force that slides the safety ring away from the base and to a position that is out of interfering contact with the end of the sucker rod, and wherein when the manually applied force is released the spring biases the safety ring against the base and in interfering contact with the movement of the end of the sucker rod from within the cavity.

