| Startining Mills : |
Used to lover the whipstock into the setting posstionand bigin the window milling operaion. After setting the whipstockand shearing the shear bolt, the the starting mill is guided by the tapere pilot as the initial starting cut-out of the casing window is bogun. |
| Windows Mill: |
used for ctting the milkmillwindow as a follow up mill to the starting mill in whipstock operations. It moves down the engled face of the whipstock face. Can be used alone or in conjuction with a watermelon mill on a joint of drill pipe. |
| Watermelon Mill: |
Can be utilised in sevwral botton-hole assemblies during the window cutting operation. it is designed to mill up or down as it elongates and dresses the casing window. Can be used directly abowe the window mill or taperd mill as well as above the first drill collar white drilling the first several feet of formation after the casing window is complete. |
| Traporod Mill: |
used to mill burn and finish all the edges of the window. Not used to cut formation. |
| String Mill: |
The string mill is a stabilizer, as well as an elengating look to assist in the milling of a longer and smoother casing window. It is run directly above the window mill in the whipstock operation. Opten used in conjunction with drill collars and taper mills when reaming out a tight. |
