Abstract: Fixed and traveling cable blocks along with first and second cable grip assemblies are supported adjacent the load to be lifted or lowered. A lifting/lowering cable is threaded through the cable grip assemblies before being secured to the load while a separate cable suspends the traveling block from the fixed block. By alternately closing one cable grip and opening the other, the load becomes movable upon the movement of the travelling block. Additionally, by closing the previously opened cable grip and opening the previously closed cable grip, the traveling block may be re-positioned or re-cycled while the load remains stationary. Upon such re-positioning, the lowering/lifting operation of the load can be repeated.

Abstract: Fixed and traveling cable blocks with first and second cable grip assemblies are supported adjacent the load to be lifted or lowered. A lifting/lowering cable is threaded through the cable grip assemblies before being secured to the load while a separate cable suspends the traveling block from the fixed block. By alternately closing one cable grip and opening the other, the load becomes movable upon the movement of the traveling block. Additionally, by closing the previously opened cable grip and opening the previously closed cable grip, the traveling block may be re-positioned or re-cycled while the load remains stationary. Upon such re-positioning, the lowreing/lifting operation of the load can be repeated.

Abstract: A method of locally supplying slack to an axially tensioned length of pipeline spanning unsupported across an undulating seabed. During pipeline deployment, the pipeline is fitted with two weighted masses that will be positioned on either side of the undulation to be spanned. These masses will be spaced a predetermined distance from each other along the seabed, this distance being less than that between them along the pipeline. Also during deployment, the mid-region of this span is vertically deflected upward while retaining the axial tension in the pipeline. Once the pipeline is properly positioned, the vertical deflection of the pipeline is reduced thereby relieving the axial tension in the pipeline while also introducing sufficient pipeline slack such that the pipeline can closely follow the contours of the undulating seabed.

Abstract: A method of recycling a portion of the overhead vapor stream to enhance ethane recovery from a demethanizer. After the overhead vapor stream is discharged from the demethanizer, a portion of it, reflux, is compressed in a cyrogenic compressor to a pressure greater than that of the demethanizer. Afterwards the pressurized reflux is chilled in a heat exchanger causing at least a portion of it, and preferably all of it, to condense to a liquid. The pressure of this condensed reflux is then equalized to that of the demethanizer across a recycle valve so that a liquid reflux can be fed back to the top of the demethanizer. This recycling of a liquid reflux enhances ethane recovery as a column bottoms product from the demethanizer.

Abstract: Fixed and traveling cable blocks along with first and second cable grip assemblies are supported adjacent the load to be lifted or lowered. A lifting/lowering cable is threaded through the cable grip assemblies before being secured to the load while a separate cable suspends the traveling block from the fixed block. By alternately closing one cable grip and opening the other, the load becomes movable upon the movement of the traveling block. Additionally, by closing the previously opened cable grip and opening the previously closed cable grip, the traveling block may be re-positioned or re-cycled while the load remains stationary. Upon such re-positioning, the lowering/lifting operation of the load can be repeated.

Abstract: A drive wheel unit for moving equipment inside a pipe. A housing is connected to associated equipment by U-joints on either side of the housing. A drive wheel which extends above the top edge of the housing is driven by a drive motor and gear reducer mounted in the housing. A brake connected to the drive motor allows precise positioning of the equipment. A hydraulic cylinder and piston arrangement and wheel attached thereto are provided at each end of the housing and are used to lift the housing into a driving position where the drive wheel is in driving engagement with the top inside surface of the pipe.

Abstract: A system and method for ocean transport of prefabricated offshore structures includes a self-propelled sea-going vessel having a submergible mid deck and one or more raised decks. Ballasting equipment is provided in the vessel for submerging the mid deck to a level at least deep enough to permit the floating of a shallow draft barge over the mid deck. The shallow draft barge carries a prefabricated offshore structure such as a drill jacket. The barge with the offshore structure loaded thereon is floated over the submerged mid deck, and the vessel is then deballasted to raise the mid deck. With the barge lifted out of the water, the barge is fixed to the vessel which may then transport the barge and its cargo over an ocean to any offshore drilling site.

Abstract: A closure assembly is lowered into the leg of an offshore jacket. Its alignment within the jacket is maintained by a series of centralizers on its outer periphery surface. A grout packer surrounding the closure assembly seals between this assembly and the inside surface of the jacket. Afterwhich grout, or some other sealant, is pumped into the annulus above the grout packer, when cured, rigidly forms a plug within the jacket leg.

Abstract: A process for separating the gas components contained in liquified natural gas wherein a small amount of heavier reflux liquid (propane, butane, pentane, iso-butane and iso-pentane) is recycled to the top of a demethanizer column. This alters its chemical equilibrium causing methane to vaporize in large quantities and to separate from the liquified feed stream. A fractionator receives the heavier demethanized liquid end product from the demethanizer column and through distillation separates the lighter ethanes and propanes from the heavier reflux liquid, a portion of the latter being recycled to the demethanizer column.

Abstract: A method for extracting natural gas liquids from a gas stream that has a high content of hydrogen and carbon dioxide is shown. This gas stream is scrubbed, dehydrated, filtered compressed and chilled prior to entering a demethanizer where the overhead residue gas consisting of hydrogen, nitrogen and methane are separated from the demethanizer bottoms product. Ths bottoms product is then warmed prior to entering a de-ethanizer where ethane, ethylene, and carbon dioxide are separated from the de-ethanizer bottoms product which consists of the heavier compounds of propylene, propane, butane, pentane and the like. The cold demethanizer residue gas is used to cool the incoming inlet gas stream via an inlet gas cooler, and expanded vapor from a high pressure separator is cross exchanged with the de-ethanizer overhead product stream.

Abstract: A process for separating natural gas constituents wherein a portion of the residue gas from the demethanizer column is cooled, expanded, partially condensed and recycled to the top of this column. This alters the chemical equilibrium in the column causing the lighter methane to vaporize and separate from the heavier constituents such as ethane, propane, etc. The lighter methane constituent rises and is removed from the top of the demethanizer column while the heavier constituents fall and are removed from the bottom of this column.

Abstract: A variable capacity floating articulated barge assembly including two barges which are pivotally connected at their mating ends. An elongated structure to be launched is jacked to initiate it sliding along skidways on each barge toward one end region where a pivotal support member finally supports this structure prior to it being launched from this barge assembly. During launching the barges and the support member of this assembly pivot with respect to each other depending upon the degree and location of the load.

Abstract: A pile lowering and coupling assembly having a plurality of latching arms pivotally secured to a follower pile that latch onto an annular catch secured to the skirt pile. A bias applied to the latching arms maintains the engagement of the follower and skirt piles by continuously urging the latching against the annular catch. Once coupled, both piles are lowered to the sea bed after which the skirt pile may be driven by applying a hammer to the free end of the follower pile which usually extends above the water surface. Once driven, the skirt pile and the follower pile are separated by removing the bias applied to the latching arms thus enabling the follower pile and the lowering and coupling assembly to be retrieved from the sea depths.

Abstract: A conductor guide assembly for conductors of an offshore well platform having a jacket with an interior pile for extending from a sea bed to above a water level which is over the sea bed. In accordance with one inventive feature, a first guide mechanism comprising a plurality of vertically spaced supports which hold the tubular conduits within the interior pile is assembled in a plurality of sections wherein the upper support of each section is provided with removable bolt-on units for supporting the first guide mechanism as successive sections are joined thereto. In accordance with another inventive feature, a second guide mechanism comprises a pair of circular plates positioned to rotate within a lower deck opening and which are connected together and define a plurality of passages for receiving the plurality of conductors that extend in the interior pile.

Abstract: An aligner and method of alignment of two tubular piles for joinder. The aligner extends from one end of one tubular pile for insertion in the other tubular pile. One or more shim members are disposed between and in engagement with the outer surface of the aligner extended portion and the inner surface of the other tubular pile when the extended portion is inserted therein for maintaining the two piles in alignment for joinder.