Gulf of Mexico Floating Drilling Tender

Drilling operations on the Gulf of Mexico continental shelf are followingtwo general plans. The first plan placed all buildings, equipment, andmaterials on a large platform while the second copies Lake Maracaibo drillingmethods by placing a minimum of equipment on the platform and using a floatingdrilling tender or drill barge anchored adjacent to the platform in an attemptto take maximum advantage of flotation in an effort to reduce costs. A complete power rig, mud pits, pipe racks, and small auxiliaries have beenplaced on the platform as shown in Figure 1, to assure proper handling ofdrilling operations under the most adverse weather. This has the economicadvantages of eliminating the fabrication of a large structure, a materialreduction of rigging up time on each structure, and elimination of delay timeon equipment while quarters and equipment placed on the tender are being riggedup. These factors have certainly proved their economic value in drill bargeoperations in the Louisiana and Texas coastal area. Naturally the heart of such an operation is the anchorage. This anchorage, topermit taking advantage of maximum economies, must hold the ship in arelatively fixed position under the following weather conditions:Winter northwestersSoutheasterly galesSevere rain squalls In hurricane weather all operations must be suspended regardless of methodof operation and the floating tender will, if possible, be moved to a protectedlocation. However, in case of an emergency the floating tender should beprepared to swing with the wind and seas on a single anchor as there is considerable doubt that either ship oranchorage could withstand the severe strains imposed by fixed anchorage inhurricane weather. Northwesters are reported to have developed wind gust velocities as high assixty miles per hour and steady winds of approximately forty-five miles perhour. Fortunately these winds do not travel a great distance over water beforearriving at our location, and, while they can possibly develop seasapproximately eight feet high, the waves are short and if taken on the bow orstern of a ship 250'Feet or more in length they should not present a difficultproblem. T.P. 2590