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Course 903 - Well Site Completion and Servicing Safety

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Special Services Operations Safety (Continued)

hobbled line

Stimulation

Well stimulation involves techniques to optimize well performance. This may include pumping of acids, energized fluids, and various other chemicals to improve formation flow characteristics.

Rig Up

Rig up is the process of spotting and assembly of equipment to perform stimulation operations.

Potential Hazards:

  • being struck by moving vehicles
  • being exposed to potential ignition and respiratory hazards
  • overexerting or receiving sprains and strains
  • being exposed to pinch points (such as, hammer union wings and hammers, pump iron and racks)
  • being hit by flying particles
  • falling from heights
  • slips, trips, and falls
  • being struck by falling equipment
  • being injured due to potential ignition of flammable or combustible carrier or base fluids

In the next tab, we will take a look at the possible solutions for the hazards involved when rigging up.

Rig Up (Continued)

Possible Solutions:

  • Preplan equipment locations and use a spotter(s) to position equipment out of fall lane of the derrick and upwind of vents, vapor and gas sources.
  • Use mechanical lifting aids, proper lifting techniques, and team lifting where appropriate.
  • Use proper hand and body positioning.
  • Wear proper PPE including fall protection and respiratory protection where appropriate.
  • Conduct a pre-job inspection to identify, then eliminate or correct hazardous work surfaces.
  • Require all non-essential personnel to stand clear.
  • Secure all elevated lines.
  • Provide adequate bonding and grounding for blending, pumping and sand transfer equipment.
  • Use hose covers or shielding for transfer or suction lines containing flammable liquids.

Pumping

blender

This process may include pumping of acids, energized fluids, and various other chemicals to improve formation flow characteristics.

Potential Hazards:

  • being struck by high-pressure lines or unexpected release of pressure (for example, mismatched or excessively worn hammer unions line failure)
  • being exposed to chemical hazards (such as, silica, toxics, and asphyxiants)
  • being exposed to high noise levels
  • slips, trips, and falls
  • overexerting or receiving sprains and strains while handling materials (such as sacks and buckets)
  • being exposed to temperature extremes
  • being exposed to radiation associated with radioactive tracer materials

Possible Solutions:

  • Require all non-essential personnel to stand clear.
  • Direct equipment operators to stay by their controls.
  • Conduct adequate pressure tests on pump(s) and lines and ensure proper valve alignment before pumping. Install a check valve as close to the well head as possible.
  • Hobble high pressure lines properly.
  • Use proper equipment inspection techniques to include hammer.
  • Wear proper personal protective equipment (such as respiratory, skin, and hearing) as appropriate for the hazards present.
  • Conduct a pre-job inspection to identify, then eliminate or correct hazardous work surfaces.
  • Use mechanical lifting aids, proper lifting techniques, and team lifting where appropriate.
  • Keep non-essential personnel away from marked-off areas where radiation hazards may be present.
  • Allow only authorized and qualified company personnel to handle radioactive tracer materials or radioactive densiometers.
  • Prevent contamination and exercise proper personal hygiene when working around radioactive materials.

Rig Down

During the rig down phase of the well site stimulation operations process, the crew dismantles the equipment. The hazards are similar to the rig up phase.

Potential Hazards:

  • being struck by moving vehicles
  • being exposed to potential ignition hazards, including flammable or combustible liquids or gases
  • being exposed to potential skin and respiratory hazards
  • overexerting or receiving sprains and strains
  • being exposed to pinch points (such as, hammer union wings and hammers, pump iron and racks)
  • being struck by particles or fluid
  • slips, trips, and falls
  • being struck by falling equipment
  • being injured due to the unexpected release of trapped pressure

Possible Solutions:

  • Use a spotter(s) to direct equipment movement.
  • Use mechanical lifting aids, proper lifting techniques, and team lifting where appropriate.
  • Use proper hand and body positioning.
  • Wear proper personal protective equipment (such as fall protection, respiratory, skin, and hearing protection) as appropriate for the hazards present.
  • Conduct a post-job inspection to identify, then eliminate or correct hazardous work surfaces.
  • Direct all non-essential personnel to stand clear.
  • Follow procedures to release trapped pressure safely.

Swabbing Operations

swabbing

Swabbing is a temporary special services process to pull fluid from the well bore through the use of wire rope and cup assembly. Swabbing is a temporary operation to determine whether the well can be made to flow.

During the process of swabbing, a swab on a wireline is used to lower the pressure in the well bore and bring well fluids to the surface when the well does not flow naturally.

A swab is a hollow mandrel fitted with swab cups used for swabbing. A swab cup is a rubber or rubberlike device on a special rod (a swab), which forms a seal between the swab and the wall of the tubing or casing.

If the well does not flow after being swabbed, a pump is installed as a permanent lifting device to bring the oil to the surface.

Swabbing equipment includes a swabbing assembly, lubricator with an oil saver, and shut-off valve on the well, also called a swabbing valve. General precautions during all swabbing operations:

  • Conduct swabbing operations during daylight hours.
  • Keep all personnel clear of the derrick or within six feet (two meters) of the wellhead during swabbing operations.
  • Locate swab tanks at least 100 feet (30 meters) from the well, where location allows.

Swabbing Operations (Continued)

Potential Hazards:

  • loss of well control
  • fire, explosive, or respiratory hazard from leakage or venting of oil or gas from tanks, lines or lubricator
  • being struck by a pressurized line
  • being exposed to a high-pressure connection failure caused by mismatched or excessively worn hammer unions
  • being struck by pressurized fluids or the lubricator when removing the lubricator from the well
  • getting strains and sprains from handling the lubricator
  • pinching fingers between swab assembly and lubricator when changing swab cups or mandrels

We will take a closer look at the possible solutions involving hazards in swabbing operations in the next tab.

Swabbing Operations (Continued)

Possible Solutions:

  • Use appropriate equipment, rated for the expected pressures, to shut in the well.
  • Inspect lubricators, swages, and unions for defects such as cuts, corrosion, and thread damage before use.
  • Adjust oil savers by remote control with a hydraulic pump placed safely away from the wellhead.
  • Train all personnel in emergency evacuation procedures.
  • Place fire extinguishers in accessible positions.
  • Move sources of potential ignition (such as, open fires for melting of babbitt) to designated areas at a safe distance from the wellhead or flammable liquid storage areas such as the swab tank before swabbing.
  • Make provisions to contain spilled flammable liquids.
  • swabbing
  • Monitor the oil saver for wear and potential leakage.
  • Remove all spillage of flammable liquids from equipment, cellars, rig floor, and ground area adjacent to the wellhead.
  • Wear proper PPE, including respiratory protection, as required.
  • Avoid approaching, walking over or standing near pressurized lines.
  • Securely anchor pressurized lines to prevent whipping or bouncing caused by pressure surges.
  • Use proper equipment inspection techniques to include hammer unions.
  • Close the shut-off valve and bleed the pressure from the lubricator before removing it.
  • Use a lubricator that will allow removal of the swab or other tools with the well shut in (valve closed).
  • Use a dolly or other method to minimize manual handling of the equipment.
  • Use a winch line, where available, not the swab line, to handle the lubricator.

Hot Oiling Operations

swabbing

In hot oiling operations, a hot oil unit circulates heated oil or similar fluids down a well bore where it dissolves and dislodges paraffin, tar-based oils and other hydrocarbon deposits. The heated oil is circulated into piping, tubing, casing, or tanks. The image to the right displays a hot oiling truck.

Potential Hazards:

  • fire or explosion hazard from contact with flammable liquids, vapors, or gases
  • being burned by hot oil or hot oil line
  • frostbite injuries from contact with propane or propane lines
  • unexpected release of pressure

We will take a look at the possible solutions to the hazards in hot oiling operations in the next tab.

Hot Oiling Operations (Continued)

Possible Solutions:

  • Locate hot oil trucks and tanks a safe distance (100 feet is recommended) from the well and out of the fall line of the derrick, if it is on site. Where impractical, use additional safety measures.
  • Position hot oil units upwind or crosswind from potential sources of flammable liquids, vapors, or gases. Wind direction indicator should be present and visible to the operator.
  • Shut down hot oiling operation immediately if a leak occurs.
  • Make fire extinguishers readily accessible to the hot oil operator.
  • Avoid parking over or placing lines containing flammable fluids under trucks or other vehicles.
  • Install check valve in the pump line as close to the well head as possible.
  • Inspect all components of the hot oil unit before each use.
  • Shut the burner down if the wind dies.
  • Shut the burner down and reposition equipment if the wind changes direction so as to create a hazard.
  • Wear proper personnel protective equipment such as heavy padded, insulated, leather gloves.
  • Do not connect heavy joints of pipe to the small nipples on the pumping.
  • Secure all hot oil and discharge lines.
  • Connect the hot oil line directly to the flow line if pump pressure exceeds safe limits (500 psi).
  • Remain clear of pressurized lines.

Snubbing

snubbing

Snubbing is the control of a tubing string while running it in or out of a well bore under pressure. A snubbing rig is used to conduct this operation. When snubbing is performed while the well is under pressure, it’s called “hydraulic workover.” See the image to the right.

Note: The special service supervisor should hold a pre-job meeting with the special service crew and other involved personnel to review responsibilities and to coordinate the operations to be performed.

Potential Hazards:

  • falling from heights
  • being exposed to an unexpected release of pressure, and loss of well control
  • being burned by a fire and explosion
  • having limited ingress and egress
  • working in an unstable basket due to lack of guy wires
  • being caught between the rig assist pull down and crows nest

Possible Solutions:

  • Ensure proper fall protection.
  • Inspect and maintain all pressure control equipment prior to operations.
  • Provide adequate means of access to and exit from the basket.
  • Provide emergency escape methods.
  • Rig all equipment should be in accordance with equipment recommendations.
  • Ensure proper body and hand placement.

Coil Tubing

coil tubing

Technology allows tubing to be manufactured in a continuous coil without joints. Coiled tubing is inserted into the well down the production casing without the need for tongs, slips, or elevators.

Potential Hazards:

  • pinching fingers and hands
  • being exposed to an unexpected release of pressure
  • getting struck by falling or shifting objects (such as suspended injector heads)
  • falling from heights

Possible Solutions:

  • Keep all fingers and hands away from pinch points (such as tubing spool, rollers, and injector head).
  • Inspect the tools and equipment before use.
  • Rig up boom trucks in accordance with manufacturer's recommendations.
  • Use fall protection.

Video

Instructions

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. The hazards associated specifically with pumping phase of the well site stimulation process on a well site include all of the following, except _____.

2. To overcome the serious hazards associated with the rig down phase of the well site stimulation process on the well site, you can do all of the following, except _____.

3. Which of the following is one of the primary hazards specifically related to hot oiling operations on a well site?

4. Hazards specifically related to hot oiling operations on a well site include all of the following, except _____.

5. Which of the following can be inserted into the well down the production casing without the need for tongs, slips, or elevators?


Have a great day!

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