GB2230988A - Torquing device - Google Patents

Abstract

A torquing device comprises a pair of arms 1 and 2 each provided with vice jaws 3 and a chain 4 by which the arms 1, 2 can be clamped to a tube 5. Each chain 4 is fixed to a hook point 7 and to the ram 8 of a hydraulic cylinder 9. A torquing cylinder 11 is fixed to the first arm 1 and has a ram 12 which is affixed to the second arm 2. In operation the device is used to torque up or break out a threaded joint on a tube. The hydraulic cylinders 9 and associated rams 8 tension the chains 4 to the tube on either side of the joint. The torquing cylinder 11 is then operated to extend the ram 12 thus forcing the arms 1 and 2 apart such that a torque is applied to the tube. The device may be manually operated. <IMAGE>

Description

TOROUING DEVICE This invention relates to a torquing device for the assembly and disassembly of threaded tubular components.

The assembly and torquing of threaded tubular components is a basic requirement of the Oil Industry.

The major proportion of tubular components comprise drill pipe, production tubing and casing, and these are normally assembled and torqued on the drill floor using hydraulically operated power tongs. There are however, other types of tubular assemblies which require to be torqued or "broken out" either on the platform, drill site or at an onshore workshop. In these cases the use of power tongs is either not suitable or not convenient.

Examples include, downhole tools, MWD assemblies, drilling motor and turbines, tubing hangers, casing shoes etc. This type of work is normally carried out onshore by specialist workshops, who have specialist torquing facilities and equipment. Such torquing equipment can handle tubulars up to 30" diameter and provide up to 150,000 ft/lbs of torque. These items of torquing equipment are large and heavy (2-5 tonnes) and are also very expensive.

Since the torquing requirements of most companies are intermittent, they cannot justify the purchase of such a high cost item of equipment, hence the work is subcontracted to a specialist. This can be expensive and time consuming particularly where components have to be brought in from the field to the nearest workshop with the necessary facilities.

It is an object of the present invention to provide a torquing device having similar capabilities to existing equipment but being both smaller and lighter.

According to the present invention there is provided a torquing device comprising first and second elongate arms arranged for longitudinally spaced engagement with a tubular and relatively rotatable about a central axis of said tubular, means being provided to clamp said arms to said tubular against rotation about the tubular and means being provided to effect movement of said arms such that a twisting torque is applied to said tubular between said arms.

Preferably the means for clamping said arms to said tubular comprise chain arrangements provided on the arms.

More preferably said chains are affixed at one end to the arms and provided with tensioning means at the other end.

Most preferably said tensioning means comprise hydraulic cylinders.

Preferably also the clamping means includes gripping means for engaging the tubular Preferably also gripping vice jaws are provided on the arms for engagement with the tubular.

Preferably also the means for effecting movement of said arms comprises a hydraulic cylinder extending between said arms.

Preferably also said hydraulic cylinder is affixed to the arms with double pivot joints.

Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings in which: Fig 1 is a simplified schematic side view of a torquing device in accordance with the present invention; Fig 2 is a side view of one embodiment of a torquing device in accordance with the present invention with various parts omitted for clarity; Fig 3 is an end view of the device of Fig 2; Fig 4 is a side view corresponding to Fig 2 with some of the previously omitted parts included; and Fig 5 is top plan view of the device of Fig 2.

Referring to Fig 1 of the drawings a torquing device in accordance with the present invention comprises a pair of arms 1 and 2 each provided with vice jaws 3 at one end. Each arm 1, 2 has a chain 4 by which the arms 1, 2 can be clamped to a tubular 5. One end of each chain 4 is fixed to a hook point 7 on the arm 1, 2 and the other end of the chain 4 is fixed to the ram 8 of a corresponding hydraulic cylinder 9 for that arm. Each cylinder 9 is mounted at one end to a bracket 10 on the arms 1, 2. A torquing cylinder 11 is fixed to the first arm 1 and has a ram 12 which is affixed to the second arm 2.

In operation the device is used to torque up or break out (reverse torque) a threaded joint on a tubular.

The hydraulic cylinders 9 and associated rams 8 tension the chains 4 so that the arms 1 and 2 are clamped to the tubular on either side of the joint. The torquing cylinder 11 is then operated to extend the ram 12 thus forcing the arms 1 and 2 apart such that a torque is applied to the tubular. The tubular is prevented from slipping and rotating in the vice jaws 3 and chains 4 by means of serrated inserts (not illustrated) fitted both in the vice jaws 3 and the chain links 4.

Break-out or reverse torque is achieved simply by reverse action of the torquing cylinder 11.

The hydraulic cylinders are designed to provide the maximum depth torque of 150,000 ft/lbs at a pressure of 3000 p.s.i..

The unit is supplied with a hydraulic power unit which can be powered by electric motor, diesel engine or even manually. For use offshore in hazardous areas, the power unit can be supplied certified to Zone 1 or Zone 2. Alternatively the torque unit can be operated directly from a rig hydraulic supply.

The device illustrated in Fig 1 is simplified to provide a clearer view of the basic operating principles. The device illustrated in Figures 2-5 provides a more detailed view of the device and for ease of reference like parts are accorded like reference numerals. However several further features of some importance are illustrated in this embodiment.

The torquing cylinder 11 and ram 12 are attached to the arms 1 and 2 by double trunnion joints 13 and 14 which avoid out of plane forces caused by the two arms not being in the same vertical plane. In addition it can be seen that the mounting brackets 10 for the cylinders 9 are mounted on the inner faces of the arms 1 and 2.

Although the torquing cylinder 11 is double acting for both make up and break out the cylinders 9 need only be single acting with spring returns.

To provide the ability to operate on different tubular diameters a plurality of hook points 7 can be provided.

Alternatively chain links may be added or removed. In the embodiment illustrated the chain cylinders 9 operate at 3000 p.s.i. and have an 8" stroke. The torquing cylinder 11 also operates at 3000 p.s.i and has a 15" stroke. If a single stroke of the torquing cylinder is insufficient the arms 1 and 2 can be reset, the chains 4 tightened and the operation repeated.

The arrangement of the cylinder 9 and chains 4 is such that during make up the cylinder 9 is the anchor point for chain tension but during break out the hook point 7 is the anchor point. As break out torque always exceeds make up torque this ensures that the greater force during break out does not overstress the cylinder which can be sized for the maximum make up force.

A typical specification of a torquing device is provided in table 1 below TABLE 1 SPECIFICATION OF TOROUE DEVICE 1. Torque Range : 0-150,000 ft (204 Kn m) 2. Diameter Range : 31/2" - 30 Diameter 3. Weight (excluding : 850 kg power unit) N.B. Unit can quickly and easily be broken down into 4 major components for transport, if required.

4. Material : Harox 400 High Tensile weldable steel. (ultimate tensile strength 1000 N/mm2) 5. Operation : Hydraulic Power Pack - electric - diesel - pneumatic - manual operation or rig hydraulic supply 6. Safety : Designed with high safety factor. No castings may be operated in hazardous areas.

This particular design of torquing device has a number of advantages over the prior art devices described. It is lower in cost, weighs less, is more compact and is thus portable. The device is thus ideal for use in remote sites and other situations where the prior art apparatus is not practical.

Modifications and improvements may be incorporated without departing from the scope of the invention.

Claims (9)

1. A torquing device comprising first and second elongate arms arranged for longitudinally spaced engagement with a tubular and relatively rotatable about a central axis of said tubular, means being provided to clamp said arms to said tubular against rotation about the tubular and means being provided to effect movement of said arms such that a twisting torque is applied to said tubular between said arms.

2. A torquing device as claimed in Claim 1, wherein the means for clamping said arms to said tubular comprises chain arrangements provided on the arms.

3. A torquing device as claimed in Claim 2, wherein said chains are affixed at one end to the arms and provided with tensioning means at the other end.

4. A torquing device as claimed in Claim 3, wherein said tensioning means comprise hydraulic cylinders.

5. A torquing device as claimed in any one of the proceeding Claims, wherein the clamping means includes gripping means for engaging the tubular.

6. A torquing device as claimed in any one of the preceding Claims, wherein gripping vice jaws are provided on the arms for engagement with the tubular.

7. A torquing device as claimed in any one of the preceding Claims, wherein the means for effecting movement of said arms comprises a hydraulic cylinder extending between said arms.

8. A torquing device as claimed in Claim 7, wherein said hydraulic cylinder is affixed to the arms with double pivot joints.

9. A torquing device substantially as hereinbefore described, with reference to and as shown in the accompanying drawings.