Safely Using Drill Collar Clamps North America Gas SPU - Wells

Introduction Drill Collar Safety Clamps are used to prevent the drill string from being dropped down hole accidentally if the slips or elevators securing the string lose their grip. When using the safety clamps, proper installation must be used to ensure the safety clamp holds the load, should the pipe not be gripped adequately in the main load carrying slip. This will best prevent pipe from sliding downward.

Operation: Safety clamps are able to handle a wide range of pipe OD’s by either adding or removing link assemblies and can be used with handles or lifting clevises. To ensure proper safety clamp operation, the proper number of intermediate tubular segments needs to be installed (Figure 1.). Figure 1: Please refer to the safety clamp’s operator manual to determine the correct number of intermediate segments.

Safety Clamp Installation: For proper safety clamp installation, refer to the operator’s manual.* An installation procedure for a safety clamp of one brand or type may be slightly different from another. For example, the procedure to install the Varco Multi Purpose Safety Clamp is as follows: Varco Multi Purpose Safety Clamp Installation Instructions Always do the following as a minimum: (Note: Never use safety clamps as hoisting equipment) Make sure the proper amount of segments are installed in the safety clamp to provide the most inserts in contact around the circumference of the pipe. Always ensure the bottom surface of the safety clamp is setting on the slips with even distribution of contact around the bottom of the safety clamp. Continued… * A DVD that briefly demonstrates the use of a safety clamp is available from PETEX. Titled: Part V of the Roughneck Training Series: Care and Handling of Rotary Slips http://www.utexas.edu/ce/petex/aids/av/roughneck-training-series/

Safety Clamp Installation: Varco Safety Clamp (Continued) Varco Multi Purpose Safety Clamp Installation Instructions Ensure the safety clamp is evenly tightened around the pipe. One procedure to ensure this is to: First tighten nut with the safety clamp hammer wrench by hand. Tap on the top of the safety clamp at each hinge pin with a hammer, ensuring safety clamp is level. Repeat steps i and ii until the safety clamp inserts are fully seated around the pipe and the wrench can not be turned by hand. With the hammer wrench firmly seated on the safety clamp nut, strike the hammer wrench with a hammer until nut is securely tightened. Repeat steps ii and iv until safety clamp nut is fully tightened. As a last check, slowly lower the traveling blocks, and transfer the pipe weight to the slips; checking to ensure the pipe does not slide in the slips. Again, this installation procedure is intended for the Varco Multi Purpose Safety Clamp. If a safety clamp of another type or brand is used, it is strongly recommended that the operator’s manual for that particular clamp is read and understood before use.

Figure 2: Clamp in Storage Case Maintenance: Safety clamps shall be lubricated regularly, both during use and while being stored to prevent corrosion. While in storage, the clamp shall be placed in its case and filled with oil (Figure 2). A lithium-based grease (or equivalent) should be used to grease the tool. Figure 2: Clamp in Storage Case

Maintenance: (Tool Maintenance & Repair) Preventative maintenance provides a systematic inspection which reduces the risk of failure and prolongs the life of the clamp (Figures 3 & 4). It is also recommended that a Safety Clamp undergoes factory magnetic particle inspection a minimum of once every six months and load tested once a year. Tool Maintenance Action Frequency - Visually examine Die Slots for wear Daily - Visually examine Hinge Pin for wear - Visually examine Screw and Nut for wear - Check for missing Springs, Cotter Keys, and Worn Pins Yearly - Check Inserts for even wear - Check Makeup Nut and screw for bad threads - Check Clamp parts for wear and cracks Before each job Repair Part Wear Data Screw Replace if threads are damaged Nut Springs Replace if there are signs of wear and/or fatigue Cotter Pins Pins Inserts Replace if teeth are rounded, broken, or missing Die Slots Replace if there are signs of excessive wear. Pin Holes Do not use over size pins and attempt to weld. Figure 3: Preventative maintenance begins with daily inspections. Figure 4: Basic repairs if tool is damaged.

Safety Instructions Operating Hazards A drill collar clamp attached to a drill collar shall not be hoisted over head-height into derrick. A dropped safety clamp has the potential to cause serious injury or death. Do not operate the safety clamp without the proper number of tubular segments being installed. Use of the clamps with the improper number of segments can cause serious injury. Ensure the clamp is properly tightened around the pipe. Failure to properly tighten the clamp could cause the clamp to malfunction and cause serious injury. Workplace Hazards Keep hands / fingers clear of clamp segments when installing the clamps on the pipe. Wear proper hand protection. Maintain a balanced body position and secure footing. Maintenance Hazards Improper welding and/or re-machining of cast alloy heat treated steel can cause the structural integrity of the clamp to fail, thus resulting in personal injury, property damage, or death. If pin holes or die slots show excessive wear, discard and replace them. Do not use oversize pins or attempt to weld them. Discard and replace worn pins.