Pigging: increasing appreciation of an industry truly come of age. (A Pipeline & Gas Journal Staff Report).
Both government regulations and economic sense have combined to drive the need for dynamic value engineering in pipeline operations. All aspects of pigging have moved steadily forward with combinations of functions through modularization providing popular savings. Built-for-purpose is the clarion call these days and clever designing and the sophisticated selection of suitable materials have brought outstanding product development to the benefit of pipeline operations at just the right time.
This is particularly true of pigs for gas lines where wear and seizure of moving parts is a problem. Here, pigability is being enhanced by giving more attention to the internal surface of lines and by more carefully considering operational conditions. These then optimize the capabilities of even already well-specified pigs; so better usage is also obtained.
Here are just a few of the developments in recent months that are putting the smiles back on grizzly pipeline operators faces.
General & Regular Pigging
TDW recently designed and fabricated a sloped, automated pig launcher. This product is new to the pigging industry and was inspired by an application that required a unique design solution. An innovative products pipeline company operating in Chile had just completed a new 16-inch, 130-km (81-mile) pipeline through which it is batching seven different refined products. The application required that four pigs he loaded into the launcher with the ability to launch single pigs at two-minute time intervals.
The launcher also had to be capable of launching a corrosion inspection pig and the launch had to be conducted with either a remote or local signal. To avoid a vertical unit, which would have been very tall, TDW conducted Tests to determine the minimum angle required to slide the TDW VANTAGE V-4CC Pig equipped with RealSeal Cups into launch position. Once this was determined, launch pins with automated controls were incorporated into the design.
A novel design of dual-diameter Paddle Pig has been launched by Pipeline Engineering Solutions, a division of Pipeline Engineering (PE). Cost-effective and efficient, it is claimed to offer pipeline operators the solution to pigging dual and multi-diameter pipelines during pre-commissioning, pre-inspection and routine operations. It is capable of towing inspection pigs. even with high drag. The system works by using polyurethane paddles to support the pig on the centerline of the larger pipe. Each paddle then collapses by rotation into the smaller diameter pipe. Sealing is performed by standard disc-type seals in both diameters. The design and technique have been patented world-wide.
The new pig satisfies the fundamental requirement that it must have seals that provide the drive in each size. It allows changes in line size currently estimated at up to a 60 percent increase. Typical diameter combinations that can be handled include 10 in x 16-in and 28-inch x 42-inch. By advancing the boundaries of what has seemed safely feasible. much greater flexibility in pipeline design is foreseen. Potentially, high savings are possible and a special benefit in the exploitation of marginal fields. Since every pipeline is different, each pig's design and development is a bespoken product for every application. Currently, with all dual and multi-diameter pigs of this tape requiring step changes to be tested for conformity, PE is also providing proving trials as necessary.
In signaling, Enduro's Pig Popper Model PPM is claimed finally to nail the rumor that some devices don't really work too well. Pipeline Inspection Company's latest Pipe Tracker Sensor (PTS) mounts directly onto the line for either occasional or permanent deployment and allows for a visual indicator to be fitted. And CDI's enhanced CD42 pipeline pig location/tracking systems offer operators speedy, comprehensive and accurate monitoring of every aspect of pigging activity in both onshore and offshore pipelining situations.
An especially innovative development is the OptionAll Pig from T.D. Williamson, Inc. Its standard components can be assembled to make a multitude of configurations designed to handle most pigging needs. TDW is offering custom-built pigs to specification and standard sizes are available in 4-inch through 14-inch sizes. After initial purchase, the customer needs only to obtain the necessary cups, discs or brushes, as the hard, polyurethane pig body is reusable.
Enduro's latest Advantage pigs for cleaning, purging and hatching are available with an even wider selection of ancillary and auxiliary items like cups, discs, brushes, magnets. paraffin plow blades--with tandem build-up and inspection equipment as needed; and its range now includes the flexible polyurethane Pig Links that allow even ID bends to be negotiated
Pigs Unlimited's comprehensive ranges of pigging products and services and Knapp Polly Pig's Ultra-Pig and BD-6K were further enhanced to users' needs. New models are now also available from Pipeline Cleaners, Pipeline Engineering, Pigs Unlimited, Nautronix and Ura-Flex Manufacturing.
Cornerstone Pipeline Inspection Group has introduced a new generation of high-resolution ILI intelligent pig systems claimed to minimize or eliminate unnecessary and expensive pipeline modifications. Capable of inspecting long sections of line in one pass, CPIG tools are relatively short, allowing them to pass 1.5D bends and up to 25% OD bore reductions.
An especially versatile system, the Vertiline tethered inspections service from Baker Hughes PMG (Pipeline Management Group) is said to offer important savings in lines where ILI intelligent pigging has not been possible. This wireline conveyed system carries out targeted MFL inspections, detecting and quantifying both internal and external corrosion in lines from 2-32-inch diameter. From a single access point, its instruments can analyze quickly segments up to four miles in length. Data collected in real time can be delivered to site for immediate verification digs or repairs.
Using only very few bell-hole access points. Petrochem Inspection Services' long-range ultrasonic Teletest equipment is also proving effective on previously unpiggable lines.
Tuboscope multiple-technology tools have been well-received as they provide a comprehensive picture of pipeline conditions. They have multi-axis sensors and magnetics along with mechanical damage detection arrays, INS/GPS and speed control. Likewise its deformation/geometry survey tools. These offer high resolution deformation information needed to pinpoint mechanical anomalies and high-stress areas and to assess the need for repairs, prioritize maintenance activities and reduce the risk of costly failures. There are also high-resolution corrosion survey tools that deliver unfiltered data.
Using the latest sensor technology and advanced data acquisition capabilities they are claimed to give an accurate and comprehensive profile of a pipeline. And the company's XYZ coordinate survey tools depict the exact location of a pipeline and surrounding area. These are now" available in a single, integrated package with Tuboscope Pipeline Services' leading MFL or deformation survey tools to pinpoint the exact locations of pipeline features and the surrounding environment.
Rosen has brought in its combined technologies 6-inch metal-loss/XYZ mapping tool. This multi-purpose tool is of modular design and is said to be capable of inspecting almost all 6-inch pipelines in one run and effectively pass through 1.5D bends. Its results are compatible with all major GIS programs.
Vee Kay Vikram & Co. is now offering caliper pigging services (electronic geometry pigging) using caliper tools of sizes from 8-24-inch. Tools for larger sizes are in final stages of completion. Test loops for a comprehensive range of calibration tests have been erected and VKV is floating a new company. Graffin Technologies, offering integrated pipeline data acquisition services with various specialized pigging tools. It also has an advanced R&D program for developing electronic gage plate pigs and mapping tools.
The Advanced Profile Tool (APT) from Profile International differs from conventional caliper pigs in that it stores data from a minimum of 16 independent sensors positioned radially around the pig body. These sensors provide independent radius measurements as opposed to a single minimum internal diameter measurement. This allows detailed evaluation of pipeline features. Sensor resolution on radius measurement is 1 mm and sensitivity on detection of bore changes is the larger of 0.5% of nominal pipe diameter or 2 mm.
Collection of the data is distance triggered, using pulses from a pair of odometer wheels. Pulses from the odometer wheels are fed through a fastest of two discriminators to minimize the effects of wheel slippage. The axial scan pitch can be set at 3.3 mm or greater, i.e., a complete set of independent radius measurement data can be recorded at intervals of 3 mm or greater along the pipe. In addition to radius data, an azimuth signal is recorded at 6-meter intervals along the pipe and the data is time stamped. The azimuth provides an indication of which sensor is at top dead center, thus allowing life angular position of features to be identified.
The time stamp can be combined with distance measurements to provide information on pig velocity. The data is viewed using "Pigout," a custom data analysis and viewing package. This package allows the viewing of data in a number of formats, each with advantages depending on the type of features being identified. The viewing software is a windows-based package. The software allows the operator to scroll through the data, which is displayed on axes of diameter or radius, vs. distance traveled. Currently, the software allows tot simple stepping between viewing formats though new software is being developed to allow simultaneous viewing of formats.
The new range of bi-directional MFL tools from 3P Services has been attracting attention. 3P Services specialized initially in tools for small diameter in line inspection and has rapidly expanded its range for a wider variety of applications. Tools can easily negotiate 1.5D elbows as well as full diameter T-pieces. All data is downloaded on site with the company's new software systems. assessment add interpretation can be carried out on-site, if required. The tools are claimed to be the first bi-directional tools especially developed for the inspection of liquid lines. 3P Services is now offering in-line (ILI) tools in the 3-28-inch range.
There's a new geometry inspection tool from TDW Williamson. The Clock KALIPER tool is short and lightweight, which means it is easy to use and maneuver. It is currently available in standard sizes 12-48 inches. Launched into a pipeline, it can test the o'clock positioning of dents, categorize pipeline bends and specify bend radius and angles, conduct quick field analyses so customer's can have clear, accurate and reliable data on which to base repair decisions and more significantly it call assess the pipeline's condition to comply with Office of Pipeline Safety rulings.
An interesting new equipment called Watchdog has been developed by StarTrak Pigging Technologies. Based on an intelligent pig marker and using low earth orbit (LEO) satellite communications, this periodically and automatically transmits pipe/soil potentials, provides data about pig passage, location and GPS time and warns of damage.
Girard Industries has introduced a new 30-inch Sphere for use in pipelines and meter provers. The sphere has an actual outside diameter (OD) of 29-15/16-inch (29.94-inch). This means the sphere will have a built-in oversize of 2.4% or standard wall pipe, without inflation, allowing significant savings in time and manpower. All the operator has to do is fill the sphere with the appropriate liquid and begin operations. The sphere is not over-inflated so it is closer to a perfect roundness, which is required for accurate meter proving and better pipeline sealing,
Because the sphere is not under extreme internal pressure from being over inflated, it call better cope with the demands of the piping environment. The wall thickness of the sphere is thicker than spheres currently available and this translates into longer sphere life and increased operational efficiencies.
The unique design of the Series JC Cup, a jetting cup launched by Apache Pipeline Products (patent pending in USA. Canada and other countries) is said to be able to provide users with all the advantages of the Series C cup plus the added benefits of the jetting action. The turbulence created jets the debris away from the front of a cleaning pig. The grooves in the surface of the cup allow a calibrated amount of fluid to pass along the wall of the pipe to jet away wax, sand and other debris.
The jetting cup works well in oil, gas and product pipelines. It eliminates the large accumulations of wax left in scraper traps after the arrival of pigs. The grooves on the lip of the cup provide increased scraping and cutting action of standard cups. The design of the jetting grooves causes the pig to rotate as it travels, ensuring even wear of the cup, increasing cup life and reducing operating costs.
Locating accurately a blockage in a pipeline caused by sand, hydrate, wax, a stuck pig or external damage has become an urgent matter. In such circumstances there can be a large accruing loss of revenue and it is essential to deal with the blockage as quickly as possible. Pitchford In-Line has developed a system for single-phase lines whereby a pressure pulse is introduced. Echoing off the blockage, this can be detected by sensitively tuned instruments. Knowing the speed that the pulse will travel down the pipeline allows the location of the blockage to be determined in terms of the distance down the pipeline The system is best applicable to partial blockages where more than 75% of the diameter of the pipeline is obstructed.
IST Molchtechnik has introduced a new manifold that can interconnect dedicated storage tanks (up to 50) with a variety of fully piggable distribution lines (up to 20--with different diameters). This unit is all hard piped and eliminates the so-called "snake pit" of hoses, with all of its inherent process and safety risks. The manifold can be run either fully automatically with a PLC control system, or the smaller ones can be operated manually.
Development In Hand
Pipeline Engineering (PE) is sponsoring research into wax removal at the University of Durham in the UK. This is to gain a fundamental understanding of the physical mechanisms by which wax is removed from the pipeline wails. There are a number of parameters involved in the pigging process and careful selection has allowed the formation of a robust experimental model that considers the interaction of variables such as tool type, pig velocity and wax thickness and consistency. A test rig has been constructed to allow experimentation to proceed over the coming year. The research at Durham differs from previous work in this area as it will concentrate not purely on quantifying reactive threes measured at the tool due to the pressure differential across the pig. It will attempt to fully describe failure mechanism within the wax under various conditions.
And watch out for a remarkable new modular in-pipe robot developed by Advantica Technology. This multi-functional toolkit can be configured to carry out a number of different tasks by adding or removing the necessary modules. The computer driving the robot recognizes which modules are fitted and which tasks are intended. The systems should ultimately have many uses in pipeline engineering.
Besides manufacturing a full line of regular pigs, Pigs Unlimited, Inc. has focused its attention on a novel process pigging system. New to the pigging industry, process pigging--a term primarily used for process plants--consists of a closed-loop launching and receiving system. This allows the user to recover unused product in the line; minimize cross-contamination, downtime, and the use of dedicated lines; and save on labor, solvent, and wasted product.
The pig, a bi-directional unit that constantly remains in the line, is used to batch products from one area of the plant to another, as from the storage tanks to the mixing area for example, and then returns to the launcher, awaiting its next run. With the addition of pig switches, pig detectors, three-way valves and meters, the entire pigging system can be fully automated and operated by a single person in a control room. The system is claimed to result in massive savings. Applications for this system are endless, including loading and unloading lines, mixing plants, storage facilities, packaging areas, and transportation lines in the oil, gas anti other industries.
Pipeline Research has been extending its extensive experience in pigging dual and multi-diameter pipelines with large percentage changes, claimed now to be a reality without compromising on efficiency. For example, Statoil has de-watered the 28-inch x 42-inch Asgard line with results comparable to single-diameter pre-commissioning. Other successful deployments include 10-inch x 16-inch and 11-inch x 12-inch x 14-inch lines. These breakthroughs are said to result directly from improved pig centralization methods and dual diameter sealing innovations that allow the balance between support in the large diameter line and flexibility in the small diameter line to be met.
Nautronix Helle Division has expanded its range of electromagnetic pig tracking and location equipment with the addition of a diver-held electromagnetic receiver, Model 6380. This compact receiver can be used in water depths up to 300 meters (984 feet). Detection is displayed on a red LED bar graph and audible signal verification is achieved through a molded earpiece. A sensitivity control allows accurate positioning capabilities ideal for monitoring of isolation plugs. Also new is a small diameter electromagnetic transmitter, Model 2910. This unit can be used in pigs as small as 6-inch diameter. It measures only 195 mm long with a 38 mm diameter. This unit completes the range of transmitters, which are now available for use in pipes up to 42-inch.
RTD (Rontgen Technische Dienst) were pioneers in the field of motor-driven and fluid-propelled cable tools for pigging of (off)-loading pipelines with single-sided access and diameters between 6-48 inch. Ultrasonics is used because of its superior capabilities. The company has further developed its new generation of derivative cable tools. Some have been tailor-made and successfully applied on jobs in Alaska, California and Chile to inspect risers on offshore platforms built in the 70s. These risers, for a number of reasons, are not piggable with common fluid-propelled intelligent pigs.
The new riser inspection tools, equipped with a large number of ultrasonic sensors to provide full circumferential coverage, can also include a field-proven module to detect corrision in and adjacent to the weld. The tools are of modular articulated design and use a combination of gravity and a powerful motor propulsion module to negotiate horizontal parts and a number of bends. Depending on the complexity of the riser configuration, the full riser can be inspected including a part on the sea floor.
In case of gas risers a field proven procedure with sealing pigs is used to fill the riser with a liquid to enable ultrasonic inspection. To further increase the corrosion detection performance of these multi-diameter tools, intended for sizes up to 12 inches, a rotating sensing module (pictured below) has successfully been tested prior to a challenging inspection job. This inspection will be performed in a number of 10-inch pipelines with many bends and great elevation differences in a densely populated area of Brazil.
Meanwhile, Inline Services Inc. continued its growth with the acquisition of Pipeline Cleaners (PLC) from BJ Pipeline & Process Services. PLC specializes in mandrel pig designs and brushes, Inline has acquired a distribution ship for the Aceco Launcher and Receiver Ball Valves as an alternative to conventional launching and receiving designs. The Aceco Valve is installed in-line as would a typical ball valve.
Inline has also become the North & South American distributor for the PCOM line of non-intrusive pig detectors and pig monitoring systems. The detector can be equipped with options which include a radio transmitter that can communicate wireless to other PCOM units as well as handheld remote receivers. These new specialty products will he added in Inline's current product lines which include industry leaders such as Knapp Polly Pig, Nautronix Offshore Pig tracking Equipment, and Apache Mechanical Pig Detectors.
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|Title Annotation:||pigging equipment and supplies for the pipeline industry|
|Comment:||Pigging: increasing appreciation of an industry truly come of age. (A Pipeline & Gas Journal Staff Report).(pigging equipment and supplies for the pipeline industry)|
|Publication:||Pipeline & Gas Journal|
|Date:||Aug 1, 2002|
|Previous Article:||How to get more out of your pigging runs. (2002 PPSA Special Section).|
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