Free 2,000 page industry supply catalog
The "Industrial Supplies Buyer's Guide," a free 2,000 page catalog, offers a selection of industrial and safety supplies. There are more than 200 pages of new products inside including hand tools, first aid, material handling, pneumatics/hydraulics, plasticware/glassware, and storage systems.
Every price in the catalog is guaranteed through Dec. 31, 2000, the company says.
Source: Lab Safety Supply Inc., Box 1368, Janesville, WI 53547-1368.
New downhole dredgehead
The removal of subsea wellheads and the subsequent plugging of the well can often be compromised by materials that have settled not only around but also inside the structure-from muds, sands, and other sediments to shells and small pieces of debris.
Normally diver-operated dredges have proved effective in removing these materials, particularly where the buildup is around the outside of the oil-field structure. What has often proved more difficult is to remove materials that have settled inside the wellhead.
A new downhole dredgehead for the Barracuda jet-pump system complements the system's standard diver-operated hand pump.
The new internal head, called the "bullet," consists of a 100 mm jet pump within a streamlined aluminum housing designed to pass through the concentric wellhead casings without snagging. With a diameter of 7 in., it can dredge within the 95/8 in. central casing of a wellhead. The dredge provides a primary suction action capable of removing soft sediments at a rate of 30-50 tonnes/hr plus a jetting action to dislodge or nudge any difficult materials in the hole, using as many as eight agitation jets.
Lines into the Bullet include water to power the jet pump and a discharge hose to remove sediments and small debris. These are introduced via a specially designed manifold, which this firm is able to customize for the particular wellhead application. The Bullet head weighs about 40 kg and is normally lowered into the wellhead directly from the diver's downline. A separate hose from the manifold allows the diver to connect the head to the motive water pipes. The Bullet can reach 100 m into a wellhead. A 6-m-long rod attached above the manifold guides the Bullet into the casings. The system is rated to work at depths of 300 m, subject to hose handling.
The company also offer a Barracuda dredgehead for dredging outside the wellhead. It weighs just 10 kg underwater and can remove most soft sands and sediments including particles up to 75 mm in size. It can operate at typical production rates of 30 tonnes/hr to as high as 50 tonnes/hr in free-flowing sands in 30 m of water.
The external head also incorporates water jetting/agitation nozzles, which fluidize the sediments to assist their entrainment. The number of jets can be increased for more difficult materials such as hard silts and clays. Oversized materials are prevented from blocking the dredge by an integral inlet guard.
Source: Andrews Genflo, Salmon Rd., Great Yarmouth, England, NR30 3QS.
Inspection pigs for oil and gas pipelines
A versatile new range of inspection pigs measures geometrical parameters in oil and gas pipelines. These include pigs for measuring internal diameter, for determining pipe-liner condition, for wax and scale measurement, and for localized pipe mapping to detect profile deviations. All pigs in the range can be configured specifically for any particular operation using different sensor packs as required.
These advanced geometry pigs (AGPs) are designed on a modular basis using standard disk pigs as the carrier for the AGP acquisition pack and a range of sensor options. The basic tool is a high-resolution caliper pig for measuring defects such as dents, creases, wrinkles, and other bore changes. It has been designed with independent radial sensors and multichannel data acquisition capabilities and provides accurate fingerprinting of features and anomalies as well as the measurement of bend direction and angle.
The tool can be reconfigured with 16 independent sensors for measuring the thickness of an internal liner or, alternatively, it can be configured with a combination of thickness sensors and caliper sensors for accurate bore and liner measurement. Using the combination of liner and caliper sensors provides a means of identifying and quantifying liner failure.
When configured with thickness sensors, the AGP can also be used to measure the thickness of deposits on the pipe wall. Wax buildup in crude oil pipelines is a common problem and regular cleaning is required with multiple runs of various pigs to maintain the flow. The AGP can be used to survey crude lines before, during, or after cleaning, and the information can be used by the pipeline operator to assess the effectiveness of the cleaning operations, optimize the use of the cleaning pigs, and reduce the cost of cleaning.
On the mapping pack, a strap-down inertial sensing system provides 3D geometric data on the position of the pig as it passes through the line. The data are processed to produce short-range deviations of the pipe, which can be used to assess bend radius and displacement of the pipeline-and ultimately compute the bending strain in the pipe.
Equipment is available for operational pipe diameters of 8-48 in., and the pigs can cover up to 100 km at velocities up to 4 m/sec (13 fps) through a minimum bend radius of 1.5 D.
Source: Advanced Engineering Solutions Ltd., South Nelson Rd., South Nelson Industrial Estate, Cramlington, Northumberland, NE23 1WF, UK.
