Casing exit systems are used to sidetrack a wellbore for many reasons, including re-entry of an existing wellbore, drilling a bottomhole assembly that has become stuck and is too costly to fish out, severe formation or drilling problems, the need to change the direction of a wellbore, or the need to drill multiple exits from a single wellbore.

 

Big Rig one-mill casing exit system is retrievable and has two retrieval tool options to accommodate severe hole conditions. A complete system includes a whipstock combination, an orientation device, an anchoring device, and a milling tool. This system provides a quicker kickoff with a higher build rate in short-radius drilling applications. Decreased length of the whipstock and a milling assembly consisting of only one multi-section mill form a significantly shorter window exit bottomhole assembly (BHA). The reduced-length BHA is capable of passing through higher doglegs in the wellbore. Our whipstock system provides an effective means to exit casing and provide a window to run drilling BHA, liners, and completion equipment through.

 

Big Rig field-proven fixed lug retrieving tool provides a safe, reliable way to engage our retrievable whipstock and remove it from the wellbore. Design features ensure that the lug can be re-engaged repeatedly as needed, and that the whipstock cannot be dropped while it is being pulled out of hole.

Big Rig recommends using the fixed lug retrieving tool as the primary method because it

can release from the whipstock at any given point and then re-engage as needed.

For retrieving a whipstock, the preferred bottomhole assembly includes the fixed lug retrieving

tool, jars, and drill collars. The lug is lowered to the correct measured depth and slowly reciprocated up and down, and can be oriented.

If the lug does not engage, the workstring should be turned and reciprocated up and down again. This process can be repeated until the lug engages. After the lug engages, the whipstock can be retrieved by releasing the anchor or packer below. Set-down weight can be applied without disengaging if the jars need to be recocked. The fixed lug can be released by applying a small amount of right-hand torque and lowering the lug through the neutral point.