Fielding

Fielding photo 01

The GasGun is simple and easy to field. The propellant is conveyed to the formation in a high-strength hollow steel carrier under a fluid column that tamps the charge and assures that the energy is restricted to the pay zone (see Energy Loss Calculations). The fluid can be anything compatible with the formation such as fresh water, brine, oil, solvent.

The tool is usually fielded on wireline or tubing conveyed. It attaches to the wireline like a perforating gun, and is most often run using a casing collar locator. The tool is ignited while suspended at the correct correlated depth. Pressure control equipment, such as a lubricator, can be used when needed.

Fielding Photo 02The GasGun is compatible with both open hole and cased hole completions. Perforated casing must be of good quality and have proper cement bond. Experience has shown that a perforation density of 6 shots per foot with a 0.375″ entry hole diameter or larger is a recommended minimum for the 3.375″ and 4″ OD GasGun systems. A perforation density of 6 shots per foot with a 0.25″ entry hole or larger is the recommended minimum for the 2″ OD GasGun system. Larger diameters are preferred if available from your wireline company.

Typically little or no cleanup is required, and your well can usually be put back on production immediately after the stimulation.

Well Preparation and Fielding Guidelines

  • A minimum tubing size of 2.875″ is required for clearance with the use of the 2″ OD GasGun system. A minimum casing size of 4.5” or a 3.875” open hole is required for clearance with the use of the 3.375″ GasGun carrier. A minimum casing size of 7” or a 6” open hole is required for clearance with the use of the 4″ carrier.
  • Maximum 1-hour temperature rating is 280 F (138 C). Maximum 10-hour temperature rating is 260 F (127 C). **Warning: Exceeding the maximum temperature ratings can result in unintentional detonation.**
  • A minimum fluid column of 300 feet (100m) is recommended. An optimal level is 1000 feet (300m) or more.
  • Maintain a minimum 100 foot air cushion between the top of the fluid and the wellhead.
  • The fluid column can be anything compatible with the formation such as fresh water, brine, KCL water, oil, diesel, and most acids.
  • In cased hole wells, perforation density of 6 shots per foot with a 0.375″ entry hole diameter or larger is a recommended minimum for the 3.375″ and 4″ OD GasGun systems. Larger entry holes are preferred over deep penetration.
  • A perforation density of 6 shots per foot with a 0.25″ entry hole or larger is the recommended minimum for the 2″ OD GasGun system.
  • Minimum distance from PBTD is 15 feet
  • Minimum distance of 80 feet between a GasGun and a packer.
  • If there is a bridge plug in the well it is recommended that there be at least 20 feet of cement on top of it.
  • In open-hole wells no perforations are required.