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发表于 2008-3-13 12:56
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来自： 新加坡
三用工作船 AHTS 和 平台供应船 PSV / OSV
Anchor Handling Towing Supply (AHTS)
Anchor Handling Towing Supply vessels, or AHTS vessels, tow rigs from one location to another and are equipped with powerful winches which are used to lift and position the rig’s anchors. In addition, many can carry moderate amounts of supplies such as drilling fluid or drill pipe and also support offshore construction projects. Variations of the AHTS vessel include those that can only handle anchors and tow rigs (i.e. they can’t carry supplies) and others that can only do towing work. AHTS vessels are usually specified in terms of horsepower (BHP) and towing capacity.
The current size of the AHTS fleet at 1562 vessels with another 120 on order, according to Clarkson research. Almost 75% are over 20 years old. We do not believe that all 1562 are still working in the oil industry and would not be surprised to find out that many of those boats are not actively employed or that they are in such a state of disrepair that they will never work.
New generation, deep-water capable vessels typically have much greater horsepower (at least 8000 BHP) and winch strength (at least 250 tons). Winch strength determines the size of an anchor and the maximum depth to which it can be placed. In addition, their winches also have longer spooling lengths, which are needed to place anchors in deeper waters. Most have dynamic positioning capability (although that is not an absolute requirement). Dynamic positioned vessels use global positioning systems and computer controlled propulsion systems that allow the boat to maintain an exact position, regardless of wave and wind forces. In addition, a vessel that is typically built today can carry more supplies than its 25-year-old peers.
Offshore Supply Vessels (OSVs) / Platform Supply Vessels (PSVs)
Offshore Supply Vessels, or OSVs, deliver drilling supplies such as liquid mud, dry bulk cement, fuel, drinking water, drill pipe, casing and a variety of other supplies to drilling rigs and platform. OSVs are also referred to as PSVs (Platform Supply Vessels) – they are the same thing, although some industry participants like to think of a PSV as the larger version of an OSV. Offshore supply boats are usually specified in terms of cargo carrying capacity, measured in dead weight tons (dwt), but it is more common just to specify the boat by its length (in general, the two specifications are highly correlated).
We estimate the size of the current OSV fleet at about 1014 boats, with another 84 on order. Sixty-three percent of the fleet is over the age of 20 years. We do not believe that all 1014 are still working in the oil industry and would not be surprised to find out that many of those boats are not actively employed or that they are in such a state of disrepair that they will never work.
The majority of boats in service are old, legacy boats built during the boom in the late 1970s/early 1980s. A typical boat from that era is about 180 ft. (55m) long, can carry about 1200 barrels of liquid mud and about 1000 tons (dead weight tons, or dwt) of deck cargo. In addition, keeping this type of boat on station beside the rig or platform was closely tied to the captain’s ability to read the wind and waves and make adjustments using a single bow thruster and an antiquated control system. New generation boats can carry three to ten times as much liquid mud, two to four times as much deck cargo and the captain has a joystick and computer assisted global positioning systems with multiple thrusters to control the boat. We summarize the differences between the boats built in the late 1970s and early 1980s relative to boats built today in Table 4 below.
One important point worth mentioning is that not all new generation boats are deepwater capable. This is particularly true for OSV class boats. New generation OSVs that are not deepwater capable are still much superior to their older 180 foot peers. However, they still cannot challenge new generation deepwater boats when competing for work in deepwater environments. We believe that most new boats under construction will be deepwater capable (but not all). Tidewater, the largest player in the industry has a relatively large number of new generation boats that were not designed for the deepwater.
Crew Boats
Crew boats transport personnel to, from, and between offshore rigs and platforms. These boats are much smaller than their AHTS or OSV cousins, and can range in size from 75 ft to 190 ft (23m – 58m). Crew boats are generally specified by cruising speed. The smallest boats (75 ft) are typically used to transport crews between offshore installations and not to and from shore. |
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