Packers Single or Straddle (double) Packer Assemblies

P/N Packer1

Types
Packers come in two basic types, fixed end or sliding. A fixed end packer expands in the middle as its inflated, pressing against the side of the borehole. They are generally lower cost but are limited by lower inflation pressures (up to 500psi) and the amount of packer area that seals the borehole. A sliding packer has a center pipe or mandrel running the length of the packer. As the packer is inflated the bottom of the packer begins to slide up the mandrel. This allows a larger area of the packer to seal against the borehole. Sliding packers allow for the greater inflation pressures needed for jobs like hydrofracturing, injecting or fracturing.

Configurations

Depending on your work, packers can be set up differently to achieve the goal. Single Packer can be used for grouting, casing tests, fracture tests, hydrofracturing, or sealing off a section of the well. A pump can be added to a packer to test or pump from an area of the well. The straddle packer assembly consists on two packers, upper and lower with piped section in the middle, usually ten feet.

The center pipe is perforated to allow injecting or pumping for sampling. Moving the Straddle Packer assembly down the well allows testing of each water bearing zone for flow, water qualities, or contamination entering the well. Pumps can be lower inside the drill string if small enough, larger pumps can be mounted between the packers using shrouds. Placing transducers above and below packers allow you to test for different changes in the zones while working.

Using transducers can not only tell you water level changes are taking place but if in fact the packers are properly sealed against the borehole. Getting quality real time data with transducers in the zones can be tricky. Previously cables for the transducers had to be fished into each zone when building the packer assembly, requiring cutting and splicing of the data cables. EE/S has developed a method for getting real time data readings from each zone without the fishing of cables through the assembly.

Installation

Wire line or Drill Strings are the two ways to lower the packer in the well. The wire line or cable is normally used for lowering a single packer when no pumping is required. Using the drill string or pipe to place the packer is the preferred method. Pipe allows for better control and using pipe allows you direct access into the zone below the top packer for pumping, injecting, or measuring.

Nitrogen works best for inflating packers but water or compressed air has certain applications. With the use of a double valve system mounted with a nitrogen regulator, packers can be inflated separately or at the same time. Using the valve system with regulator and pressure transducers allows the monitoring of each zone to assure proper inflation and sealing of the borehole. Once you know this is the case, you can be confident of the results.

Environmental Equipment and Supply rents and sells TAM International Packers along with pumps and transducers. If you need help designing or purchasing a packer assembly for your next project, call Larry or Bill at 800-739-7706.