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Course 902 - Well Site Preparation and Drilling Safety

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Drilling Ahead Safety (Continued)


Preparing to Break Out Pipe

In this process, the driller stops the drill string from rotating, and hoists the drill string with the drawworks until the kelly is out of the rotary table.

The driller then shuts down the mud pump(s). The floor hands set the slips around the joint of pipe. The tongs are then latched onto the tool joints above and below the connection.

Potential Hazards:

  • pinching fingers or other body parts between slips or slip handles and rotary table
  • experiencing muscle strain from improper lifting technique
  • pinching fingers when latching the tongs onto the pipe

Possible Solutions:

Implement effective, safe work procedures for using slips and tongs, which include:

  • Proper finger and hand placement on slip handles and tong handles
  • Proper stance and slip lifting techniques
  • Proper tong latching techniques

Breaking Out Pipe

tong swing radius
Click to Enlarge

During this process, the tongs and cathead are used to break out the pipe. Either the rotary table or kelly spinner is used to spin the drill string or kelly to unscrew it from the drill pipe joint.

The diagram to the right demonstrates the “Tong Swing Radius.” It is an illustration placed on the drilling floor and is a circular area marking the tong swing radius or four feet from the hole center, adjacent to the mousehole. In red, from the hole center and above in the upper quarter of the circle, is an arc marked as the hazardous area. All other areas are marked in yellow for caution. Only tong operators stand in the tong swing area. All other personnel are outside. No one should stand in the red zone.

Breaking Out Pipe (Continued)


Potential Hazards:

  • Being struck by:
    • swinging tongs if the tong dies fail, or the tong counterweight lines were to break
    • the slip handles if the rotary table is used to spin the drill string
    • reverse backlash of tongs (backbiting) during spinning out operations
    • the tongs if a snub line breaks or the tongs come unlatched
    • pipe
  • Release of excess drilling mud resulting in skin contact, loss of footing, etc.

Possible Solutions:

  • Inspect tong dies, counterweight cables, and snub lines hourly and prior to each trip.
  • Implement an effective spinning out pipe procedure:
    • Personnel other than tong operators stand outside the tong swing radius when breaking pipe.
    • No one should stand in the red zone
    • Use proper tong latching techniques and use proper hand and finger placement on tong handles.
    • Stand clear of the rotary table when it is rotating.
    • Use special operational procedures when using a high torque connection.
  • Maintain good communication between floor crew and driller.
  • Use a mud bucket to direct mud down into the rotary table.
  • Close the mud saver valve on the kelly (if present).

Making Up Pipe in the Mousehole


During this process, the crew swings the kelly out over the mousehole and stabs it into a new joint of pipe.

The driller then spins up the kelly using the kelly spinner or spinning chain and the crew uses tongs to torque the joint.

Potential Hazards:

  • being struck or pinched by the kelly
  • losing footing while swinging the kelly out over the mousehole and stabbing it into a new joint of pipe
  • being struck by or caught in the spinning chain

Possible Solutions:

  • Use proper hand placement.
  • Keep the work area around the rotating table clean and clear of mud, ice, snow, debris and other materials that may cause slipping or tripping.
  • Inspect chain for broken or distorted links. Chains with the metal reduced by wear at any point less than 90 percent of its original cross section area should be discarded.
  • Lubricate and maintain guide rollers to prevent undue wear on the chain or cable.
mud pumps

Raising the Kelly and New Joint

In this procedure, the driller uses the drawworks to raise the kelly and attached joint out of the mousehole.

Potential Hazards:

  • being struck by debris or overhead objects if the traveling block runs into the crown block or if the traveling block or swivel hits the derrick
  • being struck by kelly or pipe

Possible Solutions:

  • Install a crown safety device on the drawworks and ensure proper functioning.
  • Keep personnel clear of the potential swing path of the kelly and pipe.

Adding Pipe to the String

doping connection

In this process the new joint is guided over to the drill hole, the tool joint is doped, and stabbed into the end of the pipe suspended in the rotary table with the slips.

The joints are threaded together using the pipe spinner, kelly spinner, or spinning chain. Final torque is provided by the tongs.

The drawworks lifts the kelly and attached string to facilitate removal of the slips.

Potential Hazards:

  • being struck by:
    • swinging kelly and pipe
    • tongs if the stabber misses the stump
    • the jerk or spinning chain
  • being caught between the swinging pipe and the tongs
  • being caught between the joint of pipe being stabbed and the stump
  • getting pinched between tongs or pipe spinner and pipe
  • slips, trips, and falls

Possible Solutions:

  • Never step over a jerk chain and stay clear of spinning chain when a connection is being made.
  • Keep hands away from end of stump or inside of pipe.
  • Keep feet and legs away from underneath tongs when the pipe is being stabbed.
  • Use proper tong latching techniques and hand and finger placement on tong handles.
  • Never stand or walk under suspended loads.
  • Keep the work area around the rotary table clean and clear of drilling fluids, mud, ice, snow, debris, and other materials that may cause slipping or tripping.
  • Inspect chains for worn or damaged links, and replace a chain having a broken or distorted link with the metal reduced by wear at any point less than 90 percent of its original cross section area.

Resuming Drilling

In this process, the driller starts the pump and picks up off the slips.

The drill crew then removes the slips.

The driller lowers the string until the kelly drive bushing engages the master bushing.

Once the bushings are in place, the driller begins rotating the drill string, lowers the bit back to bottom, and continues making hole.

Potential Hazards:

  • being thrown off the rotary table when engaged
  • getting caught by loose clothing

Possible Solutions:

  • Stand clear of the rotary table.



In some cases the operator orders a core sample of the formation for testing.

A special core barrel is lowered to the bottom on the drill string and is rotated to cut a core from the formation.

This core is brought to the surface and examined in a laboratory.

Potential Hazards:

  • being pinched or struck by the core barrel and associated tools during floor operation being struck by the core as it is removed from the barrel
  • encountering other hazards similar to those encountered during tripping out/in

Possible Solutions:

  • Wear appropriate PPE.
  • Instruct workers in handling and using the special tools required during drill core extraction.


Before beginning this quiz, we highly recommend you review the module material. This quiz is designed to allow you to self-check your comprehension of the module content, but only focuses on key concepts and ideas.

Read each question carefully. Select the best answer, even if more than one answer seems possible. When done, click on the "Get Quiz Answers" button. If you do not answer all the questions, you will receive an error message.

Good luck!

1. Hazards associated with preparing the break out pipe include all of the following, except _____.

2. To prevent injuries associated with preparing the break out pipe, you can do all of the following, except _____.

3. Hazards associated with making up pipe in the mousehole include all of the following, except _____.

4. Hazards associated with adding pipe to the string include all of the following, except _____.

5. To prevent injuries while coring, you can do all of the following, except _____.

Have a great day!

Important! You will receive an "error" message unless all questions are answered.