CASE HISTORIES

Master Block removal		Images (click on image to enlarge	****JavaScript based drop down DHTML menu generated by NavStudio. (OpenCube Inc. - http://www.opencube.com)****
Client	Offshore Operator
Location	Offshore Platform -Gulf of Mexico
Project Description
A 20-year old, 5000 lb Master Block had to be removed from a wellhead for maintenance. It was firmly attached to the wellhead and had become further compromised as a result of rust, corrosion and internal friction. The gap between the flange surfaces was less than 3mm, with no room to insert or use wedges, and no time to install a heavy-lift crane.
Technology Supplied
ISI Technicians provided well servicing expertise and Thinjacks manufactured for an API6A flange of 7 1/16 inches and 10,000 psi.
Work Scope
A 2mm gap was created between the Master Block and the wellhead using ISI's rust and corrosion removal expertise. The first ring of three ThinJacks was then inserted into the gap and energized hydraulically with a ThinFlate 34k system. This expanded the ThinJacks by 10-12 mm. A second ring was then used to expand the gap sufficiently to allow hydraulic spreaders to be inserted. A floating crane on a jack up barge was then able to lift the Master Block free from the wellhead.
Why ThinJack was the best solution
Time and cost budgets were critical There was no lifting or pulling capability on the structure To install a facility with sufficient force to separate the corroded flamges would first require a costly strengthening of the existing structure to bear the load of casing jacks It would then have taken time to install the new lifting and pulling facility with the attendant cost of barge and personnel ThinJack came as a complete service package and got on with the job with no disrupton to any other activities ThinJack was the cheapest and fastest solution!