Many of the issues encountered during a frac job relate to the setting tool operation, redress, and running procedures. Understanding these tools is critical when planning your completion. The two main redressable setting tool designs are the Baker and Owen setting tools. They both provide the same operation and parts, including a firing head, piston, oil chamber, and setting piston, with a different configuration. There are several sizes of Owen Style setting tools, but the 3-5/8″ Compact Setting Tool is the most prevalently used and most closely matches the Baker Style E4-20.
The Owen Style setting tool includes a firing head and top piston assembly that contains the power charge and creates the gas chamber when the actuated. The oil chamber is between the top cylinder and the top piston assembly. The oil acts as a dampener to slow the setting sequence when the power charge ignites. The created pressure acts against the bottom of the top cylinder forcing the top and bottom cylinder downward. The bottom cylinder interacts with the setting equipment of the plug to set it in the casing.
The main difference between the Baker Style and the Owen Style is the piston location. The Baker-style setting tool contains the pistons and oil chambers entirely within the tool, while the Owen piston and oil chamber are open to the well environment. The pistons are pressure balanced during run-in to prevent a preset situation. One benefit of this is that the amount of oil installed in the tool isn’t as significant as the Baker Style tool. Any excess oil will expand and leak out of the tool, reducing pre-stroke risk. Wellbore fluids will replace a gap created by too little oil during run-in. The assembly includes a shear screw between the top cylinder and the firing head to reduce preset situations further.
Owen Style Setting Tool Operation
The operation of the Owen Style setting tool is as follows:
The firing head ignites the power charge.
- 1. The power charge burns to create pressure in the gas chamber.
- 2. The pressure acts against the bottom of the top cylinder.
- 3. The shear screw shears, and as pressure increases the cylinder strokes.
- 4. The oil is forced out of the top cylinder into the wellbore as the tool strokes.
- 5. The top cylinder shifts downward into an atmospheric chamber, forcing the bottom cylinder to do the same.
- 6. The bottom cylinder transmits force to the plug wireline adapter kit setting the plug.
- 7. The 3-5/8″ Owen Style compact tool provides 10″ of stroke, more than the Baker Style 20 8.625″. The additional stroke enables the Compact tool to set some plugs the Baker cannot, such as the Boss Hog XR extended range plugs. As the name implies, the Owen Style Compact tool is 40″ long, less than ½ the length of the Baker style 20 (83.59″).
Setting Tool Redress is Still Critical
Regardless of the setting tool chosen, redress is critical to operational success. The proper redress procedure can be found in the tech unit: here.
Owen Style Setting Tool Considerations
The Baker Style setting tool holds most of the market, though the compact setting tool is the primary choice in some regions (such as the Northeast US). The connections on the Owen style setting tool to plug setting equipment are different from the Baker Style, making it critical to communicate your choice before the job. The service company must deliver the proper Setting Kit that connects the plug to the setting tool.
The setting tool is often forgotten during the planning for Plug & Perf but plays a significant role in the success of the completion operation. Ensuring that your service companies understand this and are skilled at redressing the tools will increase the performance of your completion