Tension relief of large deployed cable

[TeejT]

We are deploying a ~ 3/4" diameter cable into a well UNSUPPORTED by tubing or sucker rods by passing it from a spool over a 3' diameter sheave and into the well. The weight of the cable and attached components will be in the range of a few thousand lbs. The purpose of this is irrelevant to the question...

The cable contains a strength member and does not require vertical support but the wires inside are sensitive to crushing if the cable is squeezed. Despite the strength member, I still need to account for the possibility of failure of this member and the cable snapping.

My question is safety related, given the several thousand lbs of tension, were the cable to snap unexpectedly. I am only concerned about this when the cable is stopped and simply hanging over the sheave into the well, (not WHILE it's being lowered and the sheave is turning), as personnel have to get near the well head and attach equipment to the cable at these times when it is stopped. Does anyone know of an effective way to relieve the tension in the cable ABOVE THE WELL HEAD to prevent the possibility of injury to personnel in case the cable snaps?

Thanks very much!

 

[BigInch]

Release the cable brake on loss of load, or an axe, but wouldn't the cable actually tend to snarl up, knot and plug as the end travels up the casing, or is it not into the well very deep?

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"The problem isn't finding the solution, its trying to get to the real question." BigInch

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