An important part of heave compensating equipment, the stand-alone CCTLF can be quickly and easily installed into the derrick. The CCTLF’s compensating cylinders protect the tubing/casing string against tensile failure during DST and completion-type operations, affording tension relief from vessel heave (upwards and downwards motion). They can be used as a primary or secondary means of compensating.
A standalone unit, it is fully operational during a blackout. The cylinder(s) are mounted vertically on the frame legs and receive energy from a high pressure/liquid system. The HP air originates from the vessels APV bank and is transferred and stored in a dedicated APV bank, which is part of the complete unit inventory. HP air is delivered from the dedicated APV bank to the Compensating Coiled Tubing Lift Frame – CCTLF air/oil accumulator via a standpipe and flexible hoses.
The Compensating Coiled Tubing Lift Frame – CCTLF is specifically designed as a self-contained system to protect the tubing/casing string against tensile failure during vessel heave (upwards and downwards motion). Acceptable levels of heave for such operations are defined by the rig operator, however, shall always be within the design stroke of the Compensating Coiled Tubing Lift Frame – CCTLF. Inefficiency will increase as the stroke exceeds (10 ft). The cylinder(s) are mounted to a cross plate frame with the capability of being remotely locked to the upper lift frame (static mode) during handling, string deployment, or during periods when high tensile loads are anticipated e.g. stuck packer. This is achieved by a hydraulically actuated locking bar.
The lock bar profile design is such that the system overpressure is required to allow extension or retraction of the locking mechanism. The Compensating Coiled Tubing Lift Frame – CCTLF assembly will be outfitted with padeyes suitable for lifting and handling the assembly. The assembly will be capable of being handled onboard the vessel with rig cranes.