Español| Home | Our Story | Distributors | News | Contact Us |

| Catalog | Manual | Features | Designation | Warranty | Calculator

Cable Installation for
Deep Wells

Cable Tension During
Installation

Operational Situations

Working Loads

Receiving & Handling

Installation & Spooling

Operating and Maintenance

Common Abuses

Damage Caused by
Excessive Tension

Wire Line Spooling

Installation Tension for
Well Logging Cables Chart

Cable Damage Due
to Drum Crush

Figures 1 - 5

Example for a 7H42 Cable

Example for a 7H47 Cable

Cable Installation
Tensions

Installation Tension
Graph

Manual Menu

OPERATIONAL SITUATIONS

During logging operations there are situations that can create conditions conducive to the line being crushed.

• Compression conditions

• Slack cable

• Cable Impacts

Compression conditions.  The ".476 - Slammer" is a stiffer cable since it uses larger outer armor wires. However, no conventional logging cable is designed to be used in compression - logging cables are designed for use under tension.  Cable compression may occur in situations such as "spudding".  During compression, the inner and/outer armor wires are likely to separate and open up.  Additionally, the core may be compressed and/or distorted, causing conductors to be damaged.

Slack cable.  In situations where a tool reaches TD or encounters an obstruction or a bridge in the hole and additional cable is paid out, the tension at the surface will fall off.  When the cable is put back on the drum, the slack cable goes on first at a lower tension.  When the slack is picked up, the tension will become greater at the moment that the slack cable is totally removed and the tool weight is added to the load that the cable must support.

This slack section of cable that has gone on the winch at low tension is "soft".  Low tension in the armor wires allow the cable to be compressed under the weight of the higher tension layers that will be installed over this low tension section. This is where cable crush is very likely to occur.  If the cable tension falls below installation tension during a job, the cable should be returned to the shop immediately following the job to re-establish the proper tension profile. Many times the crushed cable problems will not show up immediately and can be prevented by reestablishing , the proper tension spooling profile.

Cable Impacts.  When a cable is pulled at high tensions momentarily but repeatedly to work a tool free, the cable experiences tension "jolts" or "impacts".  Such tension impacts are more likely to cause problems than a slowly increasing tension or a steady pull.  Cable impacts are somewhat akin to taking a hammer and beating on the cable at the point it goes onto the winch.  These impacts are felt by all the layers below the point where the cable is entering the winch.  Likelihood of cable damage due to crushing exists in sections spooled at lower tension than normal spooling tension under the force of these impacts.

Previous Page | Print Page