ADVANCED TECHNOLOGY

Mixing methane from natural gas with the heavier hydrocarbons butane and propane produces a low-pressure liquid that can be used as a transportation fuel. The process was developed at the University of Oklahoma (Norman) Sarkeys Energy Center. The process allows the use of natural gas without the need to liquefy or compress it. The fuel has three times more energy than the same volume of compressed gas and about 70% of the energy of gasoline by volume. The fuel is inexpensive and burns cleaner

Oct 1st, 1996

Leonard LeBlanc
Houston

Methane plus butane and propane yields transportation gas

Mixing methane from natural gas with the heavier hydrocarbons butane and propane produces a low-pressure liquid that can be used as a transportation fuel. The process was developed at the University of Oklahoma (Norman) Sarkeys Energy Center. The process allows the use of natural gas without the need to liquefy or compress it. The fuel has three times more energy than the same volume of compressed gas and about 70% of the energy of gasoline by volume. The fuel is inexpensive and burns cleaner than gasoline.

First radial friction welder to be installed

An automatic radial friction welding machine, the first of its kind offshore, will be installed aboard Stolt Comex Seaway's Seaway Falcon pipelaying unit this fall. The machine spins the pipe joint to be welded and forces it against the stationary line in the clamps. The resulting friction welds the joint quickly, providing for a rapid pipelay. The first trial of the unit will be this winter on BP's Foinaven Field west of the Shetland Islands.

Data finally confirms sequence stratigraphy

Understanding how global sea level changes created sedimentary deposits on the margins of continents allowed for the targeting of high-probability hydrocarbon zones. Twenty years ago, Exxon developed the concept of sequence stratigraphy, which sets out that sea level controls continental margin construction throughout the world. Until then, the prevailing theory was that ice sheet extension and retraction determined sequences.

Exxon declined to reveal the supporting data, because the firm was using it to target likely hydrocarbon formations. Subsequently, sequencing became better known, but never enjoyed strong support, because there was no clear indicator as to whether the element in motion was sea or land. However, the picture is beginning to clear. The Ocean Drilling Program, probing a deepwater seafloor platform off New Jersey and near the Bahamas, drilled a number of holes with a multitude of sea level changes resulting in depositional sequences. Other data from Petrobras drilling off Brazil and research into strontium level swings in the ocean by Princeton University scientist also support the Exxon concept.

Reference: Science, Vol. 272, May, 1996, p 1097.

Anisotropy helps geologists spot separate core spin

Anisotropy or grain orientation is a well-used feature in geophysics that provides valuable information about formations and strata, namely pore space content, mode and extent of deposition, and fracturing. Grain orientation, induced by deposition or localized or general magnetism, permits sound waves to travel faster in certain directions. Determining this differentiation or anisotropy can reveal much about the earth's interior.

Anisotropy was used recently to determine that the earth's inner core, made up of solid iron, spins at a different rate from the surface or even the liquid outer core. Because of the earth's magnetism, it was believed the grain orientation was north-south. As soon as seismic receivers were perfected, several things were determined.

1. A seismic receiver at a specific geographic location would note velocity changes from the same source over a period of years.

2. Also, the highest velocities seem to rotate about the northern latitudes, indicated that the inner core grain (axis of anisotropy) was not exactly north-south.

Most recently, geophysicists studying this anisotropy determined there was a difference in seismic velocities through the inner core and velocities outside, and afterward, a reversal in these velocities over a period of 28 years. From this, some concluded that earth's solid iron core spins faster in an eastward direction than the exterior. The rate was calculated at a 36-degree shift every 30 years. Most geophysicists conclude that the driver of such a shift is the magnetic field generated by the liquid outer core.

Tilt-rotor helicopter development ongoing

Development of a commercial vertical take-off-and-landing aircraft (rotate engines, or wings and engines) is continuing in the US, Europe, and Japan. Flying models of the US version, Bell-Boeing's V-22 Osprey, are being tested. Two European versions, Eurofar and Iron Bird, feature a 13-ton model for 30 passengers and a lighter six-ton model. The lighter one is about to undergo wind tunnel testing. Prototype introduction is planned for 2004. The Japanese TW-68 version is being prepared for wind tunnel testing and no prototype target date has been announced.

All three versions are being designed for several applications: a high-speed troop ferry for the military, hub feeders for commercial airlines in dense areas, and long-distance transport of petroleum workers. The US version is being designed for the military first, because of funding sources. The European version is being designed primarily as a hub feeder, Both US and European version rotate engines with large propellers on fixed wings, while the Japanese version rotates wings with fixed engines.

All three versions are being designed for forward flight speeds of 300 knots, with full hovering capabilities. Full cyclic control is present on both US and European versions, but the Japanese 90-degree wing shift will require a small tail rotor for balance. The following operating cost comparison was reported in a recent version of Rotor Journal: a propeller commuter airplane costs 15 cents/passenger/ nautical mile; a helicopter costs 90 cents/passenger/nautical mile; a tilt-rotor aircraft is expected to cost 30 cents/passenger/nautical mile.

Software mimics risks, opportunities of running oil firm

Hoskyns Group of London, in association with Enterprise Oil, has developed a computer game that mimics the operation of an oil company - replete with risks, opportunities, and consequences. Enterprise used the game to train oil executives on strategy and teamwork and also to help managers relate their work to corporate objectives. The game employs financial, operational, and geological risks.

Environmental reality of the month:

A research group at Carnegie Mellon University (Pennsylvania) found that the manufacture of paper utensils and packaging products takes twice as much energy and was more environmentally damaging than plastic products. The group, Green Design Initiative, when tracing the life cycle of manufacturing plastic products, found that plastics released 35% fewer pounds of pollution into the environment than paper products, largely because plastic products weigh much less. The group also cited plastic bumpers, which are lighter than steel bumpers and result in much less pollution over the life of the vehicle.

Copyright 1996 Offshore. All Rights Reserved.

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