Deep Well Powered Capstan
• Operator friendly package design
• Adds to wireline safety as all high tensions are contained in the derrick
• Allows deep deviated high tension wells to be managed
• Advantage over other conveyance methods
• Improves cable life
• Reduces conductor failure
• Eliminates cable crush
• Cable head can be retained for speedy rig up
• Reduces rig down time
• Improves productivity
• Reduces operating cost
• Reduces drum stress
Ideally, wireline cable should be spooled off the drum and back onto the drum at the same tension. However when the wireline is coming up-hole the line tension is much greater than when it is going down-hole. The Powered Capstan is positioned between the hole and the main winch to handle the main hoisting work. This allows constant tension between the capstan and the main winch drum. A controlled target tension on the main winch is delivered regardless of which direction the cable is running.
The Power Capstan can give up to 9,000 lbs hoisting assistance thereby allowing standard winch units to be used beyond their normal operating range and removing the need for custom winches. The Powered Capstan automatically maintains a screen selected "TARGET" tension on the main winch with the cable running in either direction. The Powered Capstan thereby eliminates “cable crush” on the drum.
A typical 4,000 lbs target can be maintained on the winch whether the actual well tension is 13,000 lbs when hoisting, or only 200 lbs when running cable down-hole into the well.
The system is fully automatic and controls synchronize the movement of the capstan and the main winch as determined by winch operator. The system allows speeds up to 300ft/min and can run
The capstan can be used either secured to the horizontal deck or supported vertically in the derrick by the elevators.
The capstan is designed for minimal maintenance needs. The steelwork has 10 year corrosion protection.
The entire units is a 3 part lift, all with DNV 2-7.1 certification. The capstan and power pack are both rated Zone 2.
Product Details - Powered Capstan
The Powered Capstan has three main components
Wire line cable is carried around twin 31" diameter torque wheels by steel segments machined to give 180° of support to the cable diameter.
The grooves are machined to suit selected cable. Freewheel speed exceeds the normal winch operating range. The control system achieves an extremely smooth application of rim pull to the running or static cable. The winch is supplied in a Transit Frame, easily removed from the side or from the top, complete with lifting slings.
The winch can be mounted horizontally to the deck or vertically in the derrick.
The winch is hydraulic powered and is ATEX and DNV 2.7-1 compliant.
The power pack provides hydraulic pressure to the Capstan Winch. The pressure is generated by either an electric or a diesel prime mover.
- Choice of Zone2 or non-hazardous
- Optional electric or diesel prime movers
- Optional Zone 2 and non hazardous certification
- Detachable 50ft or 100ft hydraulic hoses
- Fitted with 200ft multi core control cables
This item has to be under the control of the cab safety shut down system if located in a pressurized cab and is sited in Zone 2 area.
Main control panel is designed to run two independent inline tension devices, thereby eliminating the need for any electrical interface to the present well tension circuit
- Programmable Logic Controller (PLC) allows selection of "TARGET" tension
- PLC automatically maintains the winch at the selected "TARGET" tension
- PLC maintains "TARGET" tension irrespective of cable direction and well tension
- Winch operator can alter "TARGET" tension while running the job (within design parameters)
- Operator friendly screen displays all required parameters
- Analog and digital presentation for operator
- Screen options provide six control modes and preferred displays
- Alarms, sounder, settings menu, instrumentation and manual stop control of power pack
- The control options allow the program to compute using
- well signal only
- combined well and winch signals
- just the winch signal only
- Provided with it's own transit case - normally ships in the hose basket