Snubbing contractors calculate this snub force and add in a friction factor from the BOP and wall contact on either a casing or tubing string. In certain instances, thousands of feet of pipe can be moved with minimal effort since the pipe weight is at an equal state with the snub forces. The balance point occurs when there is enough pipe weight in the wellbore to equal the snub forces generated against the pipe. This transition is an equilibrium typically referred to as the "balance point". While snubbing into the hole, there is a transition point the tubular goes through from being pipe light, to pipe heavy. Pipe heavy occurs when either enough pipe has been snubbed into the well bore and fluid weight inside of the pipe is greater than the snub forces acting against the pipe in the well bore. The other two slip bowls are designated for "pipe heavy" operations. Pipe light is when the well bore forces are greater than the tubular weight in the well bore. Two slip bowls are designated for "pipe light" operations. Typically, a minimum of four slip bowls are used in snubbing operations. Stationary and travelling slips are operated in sequence to grip the pipe as it is snubbed into the well. One of the main components of a snubbing unit is the slip.
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