Swabbing is the act of pulling fluid from the well bore through the use of wire rope and cup assembly. 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.

Potential Hazard:

• Loss of well control.

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.

Potential Hazard:

• Fire, explosive, or respiratory hazard from leakage or venting of oil or gas from tanks, lines or lubricator.

Possible Solutions:

• 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.
• 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.

Potential Hazard:

• Being struck by a pressurized line.
• Being exposed to a high-pressure connection failure caused by mismatched or excessively worn hammer unions.

Possible Solutions:

• 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 (Note: This is a particular problem with 602 and 1502 and others, as they will couple but will not hold beyond the lower pressure rating number).
  • High Pressure Lines and Hammer Unions. International Association of Drilling Contractors (IADC) Alert 98-01, (1998).
  • More On Mismatched Hammer Unions. International Association of Drilling Contractors (IADC) Alert 99-33, (1999).
  • Additional Serious Incidents With Mismatched Hammer Unions. International Association of Drilling Contractors (IADC) Alert 00-15, (2000).

Potential Hazard:

• Being struck by pressurized fluids or the lubricator when removing the lubricator from the well.
• Getting strains and sprains from handling the lubricator.

Possible Solutions:

• 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.

Potential Hazard:

• Pinching fingers between swab assembly and lubricator when changing swab cups or mandrels.

Possible Solutions:

• Use a winch line, where available, not the swab line, to handle the lubricator.
• Use a lubricator that will allow removal of the swab or other tools with the well shut in (valve closed).

Additional Information:

• Standards. American Petroleum Institute (API).
  • RP 54, Occupational Safety for Oil and Gas Well Drilling and Servicing Operations. (2007, March).

Reference: osha.gov

In oil drilling, pressurized liquid is used to cool the drilling equipment, move soil and debris out of the oil’s path, and ultimately, force the oil into a path of the liquid’s creation. In order to get the process of oil production officially started or restarted, one must engage in oil well control. One way to do this is to initiate a process called well swabbing.  This is done so that the liquids that have pooled in the well during the pressurized liquid “drilling” and “cleaning” will be removed from the oil well and force the oil to gush out due to the pressure build up in the well shaft.

 

Gas and oil well pumping or swabbing devices to remove oil from an oil and gas well relying on the residual gas pressure in the well to lift the swabbing device and the attendant column of oil thereabove in said oil well casing are exemplified byU.S. Pat. Nos. 4,813,485, Coyle, 4,528,896, Edwards, 4,070,134, Gramling, and 3,179,022, Bloudoff, as well as others. Many of these devices contain a valve which, when open, permits the inherent weight of the swabbing device to cause it to sink downwithin the oil well casing through the accumulated oil and gas therein to a predetermined position near the bottom of the casing, at which time a stop or a pressure sensor will cause the valve to be closed, and as gas pressure builds up underneath theswabbing device, it and the column of oil thereabove will be raised to the surface, at which time the valve will again be opened, either automatically or manually, and the swabbing device will repeat the cycle.There are a number of stops for actuating the valve in the swabbing device disclosed in the prior art, some of which are retrievable. However, many are not. (ref: docstoc.com)

When a well is swabbed a swabbing rig is backed as closely as possible into the production zone. According to Tiger General, “these swabbing rigs normally have a winch with a cable and a foldable mast with a pulley on top. The operator raises the mast and moves it until it is aligned with the center of the well. Next, the operator lowers the cable in and out of the well via the ‘winch drum’.“ This process forces the oil to gush out from the bottom hole as the pressure is increased due to the vacuum created by the process. A batch of pumped out liquid is called a run. An average oil well usually has 6 runs before the oil or gas can properly gush out of the bottom hole.