As oilfield engineering enjoys a resurgence of interest and investment, companies continue to look to advancements in technology to both reduce costs, and improve the safety of offshore drilling operations. In particular, active heave compensation systems use advanced hydraulic cylinders and accumulators to achieve a system that reduces the relative motion of the drill pipe and the seabed, improving both efficiency and safety. In the area of active heave compensation systems, CPI’s unique subsea position sensor is seeing deployment into these applications due to its unique versatility and durability. Specifically, manufacturers and system integrators specifying hydraulic cylinders and accumulators for active heave compensation, are finding that our ATEX and IEC-EX certified sensors are perfect for both subsea, and surface use, both inside and external to the hydraulics. Position Sensing in Heave Compensation Hydraulics is Absolutely Critical. Oilfield Applications which use the CPI advanced draw wire sensor include many different types of heave compensation systems. For most of these, the CPI SL-2000 Safety Rated Linear Position Sensor, is both a versatile, and a durable solution.
The CPI SL-2000, A study in Durability and Ingenuity Our solution to harsh duty hydraulic cylinder position detection is unique in the world, and is often the only practical solution to harsh environments, and long stroke cylinder applications. Here are a few of the characteristics of our robust sensor design.
Call CPI Today to discuss your Oilfield Hydraulics Position Sensing Needs Original content posted on https://www.cpi-nj.com/blog/heave-compensation-systems-for-offshore-drilling/ As Oil and Gas companies seek to expand and extend their retrieval capabilities both on and especially offshore, concerns about safety and exploration costs are never far from mind. Things have come a long way since the tragedy of Deepwater Horizon, and technology has marched on to provide more robust safety systems for offshore drilling, while keeping costs of exploration manageable. One area of particular innovation has been in the area of Blow Out Preventers (BOP) a critical safety system in deep water mining. Blowout preventers are critical to the safety of crew, the rig and environment, and to the monitoring and maintenance of well integrity. Blowout preventers are intended to provide fail-safe operation to the systems that include them by sealing the top of the wellbore in the event of an emergency. Indeed, many will recall that the in the Deepwater Horizon blowout, the pipe line going through the BOP was slightly bent and the BOP failed to cut the pipe, contributing to the accident. One unavoidable fact is that exploitable reservoirs of oil and gas are getting more and more rare and remote, leading to increased deep sea well exploration and requiring BOPs to remain submerged for as long as a year in extreme conditions. As a result, BOP assemblies have grown larger, heavier and more complex. A key focus in the technological development of BOPs over the last two decades has been limiting their footprint and weight while simultaneously increasing their safe operating capacity. Undersea BOP meets SubSea Rated Sensor Last year CPI introduced the SL-2000, a linear position sensor unique in the world for its capabilities at the extremes of machine requirements. The sensor has both intrinsic safety ratings and a subsea capability that make it a perfect match for the unique requirements of Oil and Gas exploration machinery, residing deep below the ocean surface. One of the key functions of a BOP is to be able to deliver and remove fluid from a wellbore. This fluid is not sea water, it is typically drilling fluid or “mud” pumped from a reservoir somewhere. Critical to these systems is the knowledge of liquid levels in these enormous tanks sitting on the sea floor, miles below the surface. It’s actually a perfect job for the CPI SL-2000 Subsea rated sensor. In this BOP application, our sensor is deployed on the seawater side of a hydraulic piston type cylinder that monitors the rise and fall of liquid in the tank. The sensor is entirely exposed to sea water sitting 2 miles below the surface, running fully submerged at a pressure within 10 psi of the ambient pressure. Specifications call for for our sensor to operate in seawater at up to 6000m depth or over 8800 psi. Operation at these depths, fully immersed in sea water is actually no problem for our patented sensor technology which is uniquely designed with materials that are non-compressible, and withstand corrosive seawater and hydraulic fluids alike. Our sensor can be mounted and operate fully submerged in virtually any type of fluid medium while maintaining robust operation and an extremely long life. In this undersea tank, a hydraulic piston extends and retracts with changing fluid levels in the tank. Our sensor is required to operate within 10 psi of the pressure outside the tank and supports a 5 meter cylinder stroke length. The ability to support these massive stroke lengths, at depth and pressure, submerged in sea water or hydraulic fluids are unique to the CPI design and we are the only manufacturer in the world with a technology designed to withstand all these conditions while also being both subsea and intrinsic safety rated. Long Stroke, Deep Sea Hydraulics Have Only One Real Solution to Linear Position SensingWith the SL-2000, hydraulics destined for Oil and Gas exploration applications finally have the robust linear position sensing they need. Call our sensor team today to discuss your unique application. Original content posted on https://www.cpi-nj.com/blog/subsea-sensors-detect-reservoir-tank-levels-2-miles-under-the-sea/ Two important considerations when looking at the integration of any hydraulic linear position sensor are the underlying technology and the packaging of the transducer. These principles effect size, life, maintainability, and above all, durability.
The underlying technology used influences the linearity, repeatability, resolution, temperature immunity, maximum stroke length, emi immunity, and ability to achieve safety certifications. Things like signal conditioning are also affected and the need for sensitive, complicated electronics local to the sensor must be considered a drawback in most cases. With respect to packaging, a transducer’s internal and external construction should be rugged enough to stand up to physical abuse. Internal mounting maximally protects sensor components but then co-existence with the cylinder operation must be considered. Certain locations or attitudes subject the transducer to severe vibration that can cause catastrophic failure. Vibration and orientation of the cylinder are important as long rod-type magnetostrictive sensors for instance have a significant failure rate when deployed horizontally or subject to vibration. Enter CPI draw wire sensors in 2017 and you have a reinvented sensor tech that addresses most if not all of these concerns in the harsh duty world of offshore or underwater hydraulic operations for oil & Gas. Often referred to as “In-cylinder extensometry” CPI was the first to deploy a non-contacting, internally mountable draw wire using a linear-to-rotary-to-linear (LRL) mechanism to translate the long stroke of a hydraulic cylinder to the relatively small motion of a short-acting sensor, such as an LVDT or a very short magnetostrictive sensor. The LRL mechanism is a micrometer-like assembly, which forms the axis of a recoil spool mechanism. The spool uses a polymer-coated, stainless-steel cable to form a reliable, repeatable coupling between the piston and the sensor. Anchoring the connector to the piston causes the cable to wind or unwind from the spool as the piston rod retracts or extends, respectively. The big advantage to this technology is ease of installation – no core drilling of the piston rod is required. The assembly also offers extreme immunity to shock, vibration, and environmental factors, regardless of stroke length and no sensitivity to EMI as electronics may be removed from the sensor area. The CPI SL2000 sensor provides absolute output, and, unlike other sensor technologies it is both non-contacting, and pressure tolerant. The CPI sensor is designed to be mounted inside the cylinder housing with access provided through the protrusion of a short stroke magnetostrictive sensor. Developed initially for mobile equipment applications, our in-cylinder extensometers fill a void in the deployment of advanced hydraulic control feedback for a wide range of machinery, including offshore drilling equipment, underwater hydraulics, mining excavators, and other large scale agricultural and marine equipment. It is also one of the few sensor technologies suitable for telescoping cylinder applications. Original content posted on https://www.cpi-nj.com/blog/when-old-technology-becomes-new-again-part-ii/ The environment in which the search for oil is conducted beneath the surface of the seas is ever changing and often treacherous. It changes constantly due to the ebb and flow of the surface of the water and operation during inclement weather can be particularly treacherous. In deep water drilling, floating drill vessels are used, which are moored over the site of the well with large amounts of drilling tubular goods suspended from the anchored drilling barge, which is in constant motion. This barge is often more than a thousand feet from the ocean floor where drilling is occurring. Uncompensated stresses which compromise connections to various loads or the wellhead itself, can result in millions of dollars of additional repair expenses, long periods of downtime, and environmental disaster. In these ocean drilling platforms, motion compensation systems (aka “heave compensation) are used to nullify the effects of ocean waves on the fixed and rotating drill string and bit, wellhead risers, or in other cases, crane head tension. Systems generally fall into two categories of either active or passive heave compensation systems with active being the more modern and sophisticated of the two. Some systems use a hybrid approach, relying on active to kick in for only the most rugged conditions. Each system typically relies on the operation of one or more hydraulic cylinders or accumulators which act as “springs” to keep the load at a constant level or tension. As a way of understanding the incredible responsibility of these systems, a good heave compensation system can keep a crane load steady to within a few centimeters, in heaving seas with 10-12 meter wave heights! The Role of Linear Position Sensors in Heave Compensation Hydraulics. In active heave compensation systems, hydraulic cylinders or accumulators are manipulated by control systems which drive or drain fluid from the cylinders in response to movement detected by an MRU (Motion Reference Unit). While there are a myriad of variations on heave compensation or riser/tensioner systems, most active systems will require closed loop feedback on the position of the shaft in a hydraulic piston or accumulator over what is typically a very long stroke length.. This is an essential data point for the control system that insures both safety, and the accuracy of the overall compensation. CPI’s New Solution To An Old Problem – The SL 2000 Hydraulic Linear Position Sensor CPI’s newest sensor, the SL2000, achieves a number of things that are critical to hydraulic cylinder manufacturers attempting to deploy on the drilling platform or under water at the wellhead or surface/sea edge. ATEX & IECEx certifications – With these certifications, the SL2000 demonstrates all necessary intrinsic safety qualifications for sanctioned deployments in hazardous or combustible areas. These certifications cover regulatory requirements in both the United States and Europe. Subsea Rated, Internal Mount Capable – The new design of the SL2000 uses a short rod magnetostrictive sensor to accurately report the position of our advanced drawwire sensor. The entire sensor can be completely submerged within hydraulic fluid inside the cylinder itself and supports standardized SEACON connectors with almost any desired voltage and current signaling. Our sensor has been qualified to 1 million cycles of operation at a pressure of 5000 ft in highly oxygenated seawater. Long Stroke Lengths – Unlike other mechanically based or long rod systems, our sensor operates standard for a stroke of 10 meters. Our sensor is one of the few successfully deployed on telescoping cylinders. Even longer custom stroke lengths are available through our customization program. Cost Effective – Advances in technology and design have made the SL2000 one of the most cost effective solutions for hydraulic cylinder position sensing in harsh duty environments. The bottom line is this: If you haven’t looked looked at CPI linear position sensors for oilfield, or subsea mining hydraulics lately, then you haven’t really looked at CPI linear position sensors at all. Call us today to discuss your application or visit us at https://www.cpi-nj.com Original content posted on https://www.cpi-nj.com/blog/motion-compensation-system-hydraulics-can-get-a-whole-lot-smarter/ Interestingly when one looks back at the history of hydraulic position sensing technology some of the earliest ideas from as far back as the 1950’s revolved around both potentiometer based implementations and draw wire systems. Potentiometer based systems with their friction based wiper technology and inherent operational limitations were mostly relegated to the lab as straightforward easy to implement if non-robust solutions to measuring linear displacement.
Early draw wire sensors or “String Pots” as they were called suffered a similar fate. Also a straightforward method of mechanically determining linear displacement, it was perhaps too simple a solution to be considered elegant, or mechanically robust. Early versions after all, did use actual strings and crude spooling encoders to measure the length of the displacement. Eventually rod-type sensors were developed taking advantage of the physics of magnetostriction. By inserting a waveguide inside of a cylinder, small differences in magnetic field reflections could be detected as the piston traveled up and down. The rod (or waveguide) was carefully inserted through a center bore in the piston, running the entire stroke length. A long stroke cylinder therefore required a long rod. With longer rods came the problem of making a longer, perfectly straight center bore in the piston and making sure they fit perfectly in center of the cylinder. Despite these challenges, magnetostrictive technology is scientifically elegant, simple to manufacture, and can be highly accurate under the right conditions. So called “Magnetostrictive Sensors” became the most well used linear position sensing technology by hydraulic cylinder manufacturers. Draw Wire Sensors – The Sequel Other hydraulic linear position sensor technologies have entered the market over the years achieving some success for niche applications where their cost to performance ratio is acceptable. Microwave sensors, variable induction sensors, linear encoders, LVDT based sensors, MVDT Sensors and even new and improved versions of potentiometric sensors. Draw wire sensors, like the other technologies has seen a major reinvention as well. Satisfying a niche for extreme high endurance, draw wire sensors were reimagined by CPI in a way that retains the conceptual simplicity of the solution, but adds the technology and elegance that makes it a 21st century solution to any advanced hydraulic position sensing needs. In Part 2 of this blog we’ll talk about the key considerations in choosing a sensor and define the places where draw wire technology excels. Stay tuned. Original content posted on https://www.cpi-nj.com/blog/draw-wire-reinvented-part-1 CPI Internal Draw Wire Position Sensors Replace External Sensors in Oilfield Mast Raiser System.5/12/2017
If you’ve spent more than 5 seconds perusing the CPI Website, then you know that toughness and durability are the primary attributes of everything we make. Nowhere is this more apparent than in our newest SL2000MS, our hybrid design, long stroke linear position sensor for hydraulic cylinders and accumulators.
Our best clients for this technology are companies making long stroke hydraulics destined for some of the toughest environments in the world, and some of the toughest can be found in the world of Oil and Gas exploration both onshore and offshore. In these deployments 10 meter stroke lengths are common, often on telescoping or multistage hydraulic cylinders where achieving accurate position sensing is both extremely tough, and critically necessary. CPI SL2000 Deployed into Oil Rig Mast Raiser System Hydraulic cylinders deployed into oilfield mast raiser systems are going to be asked to endure some of the most challenging environments that hydraulic equipment will ever see on planet Earth. Temperature extremes, contamination, corrosive airbourne elements, and a demanding requirement that the actuator does not fail easily in service conspire to eliminate most position sensor technologies from consideration. Indeed, the cost of any downtime on an active rig is staggering, costing by some estimates, up to 1 million dollars a day. Recently CPI partnered with a major Hydraulic Cylinder Manufacturer to provide 6 of its SL2000 Linear Position Sensorsinto an oil industry mast raiser application for a land-based drilling platform. In this application, the CPI sensor replaces another company’s draw-wire sensor that could not survive in the application. In the mast-raiser system, double-acting telescopic cylinders are used which start out horizontally and move to a vertical orientation during operation. When considering a replacement sensor technology, our client initially considered rod type sensors but quickly eliminated this technology owing to a few important limitations.
The CPI SL2000 For Endurance and Flexibility Instead the CPI SL2000 was chosen for a number or reasons, offering a better overall solution that the previous sensor solution, or any existing rod type sensor.
CPI’s SL2000 Series represents an important breakthrough for long-stroke hydraulic cylinder position sensing. Leveraging years of magnetostrictive sensor development (the core sensing technology) while maintaining our patented hardened draw wire core, has substantially evolved the area of linear position sensor measurement for the worlds harshest, most extreme operating environments. Contact CPI today to discuss your need for harsh duty linear position sensors. Original content posted on https://www.cpi-nj.com/blog/Linear-Position-Sensor-Mast-Raiser-Hydraulics Perhaps one of the most memorable moments of my career at CPI happened over a decade ago, when CPI was first asked to produce a robust hydraulic position sensor for a large well known maker of construction vehicles and equipment. In their larger machines, rod-type sensors were being used in the control system of long stroke hydraulics but their installation was problematic, and they often failed in rough conditions.
After many months of engineering and testing CPI produced the first version of our SL series sensors. Our new sensor was durable, accurate, and used a well accepted linear position measurement principle, the draw wire. In our solution however, the draw wire mechanism was completely re-conceived and re-engineered for harsh duty and improved accuracy. The mechanical rotations of the draw wire were ingeniously coupled to an LVDT transducer system so the whole solution was non-contacting and virtually immune to all the environmental hazards, temperature and EMI your average 15 ton wheel loader runs into. The system was so unique and unlike anything that existed that we were able to receive several patents from it. Proudly we demonstrated our achievement to our client, certain that we were onto something big here. Do you know what they said? (wait for it….) “Not high-tech enough”. Maybe you’ve experienced this: one of those moments when words fail you and you’re quite sure your head will explode shortly. You see, having witnessed the amount of research into material science, alloy’s, precision engineering, and component testing that went into our sensor, all I could think was “well define high-tech!”. And so now a decade later, having seen our unique sensor gain wide acceptance in applications more diverse that we ever imagined (including construction vehicles), I’m calm enough to explain in this upcoming series, just exactly what constitutes “high-tech” in our hardened linear position sensor solution, and more importantly, why it outperforms every other sensor technology in the world for extreme duty, long stroke, or subsea applications. Original content posted on https://www.cpi-nj.com/blog/reinventing-draw-wire-sensors/ Well that’s a fine question indeed! And the answer, like the answer to many interesting new technologies, is that it depends mostly on your imagination, and your budget! Here’s just a few of the applications we’ve already been either designed into, or proposed as a solution. Applications For The CPI High Endurance Draw Wire SensorOver a 15 year period since our draw wire linear position sensor was introduced, it has evolved, improved, and now enjoys wide acceptance in high endurance, long stroke hydraulic applications across dozens of industries and military applications. Navy Vehicles – Navy subcontractors have used customized versions of our LVDT sensor for sea-going applications on surface ships and submarines. While some of these uses are proprietary, you can read here about our use of smart cylinders on the navy’s interdiction vessel, the Sea Slice. Offshore and Subsea Drilling, Mining and Refining Operations – Large scale hydraulic cylinders used in heave compensation systems and riser tensioners are typical high-endurance applications. Our subsea rated sensor can also monitor pre-charge pressure in hydraulic accumulators like those commonly used in blowout preventers at the well head. For applications above the surface or on the drilling platform, our SL 1490MS hybrid sensor is fully ATEX Intrinsic safety rated. Oil & Gas – Rig raiser systems now enjoy much improved reliability, as our internal mount sensors replace external draw wires on the mast cylinder. Commuter Trains – Telescoping pneumatic cylinders on commuter trains required sensors for a closed-loop feedback system to assist in rail car coupling. Onshore Mining – Remote hydraulic valve actuators can be reliably monitored with use of our external-mount 1M sensor, which easily mounts onto any NFPA cylinder. In-Plant Chemical Processing – External draw wire applications on linear and valve actuators include hazardous chemical, paper processing, as well as oil refinery installations. Internal applications range from hydraulic roller tensioners in paper manufacturing to telescoping cylinders used in pharmaceutical processing. Telescoping Cylinders – CPI sensors are one of the only high endurance linear position sensor solutions in the world for this class of hydraulics. Our sensors have the ability to mount either inside or outside the cylinder, in any type of hydraulic fluid or gas atmosphere, with stroke lengths available up to 15m. Infrastructure, Hydroelectric – Dam gate actuators are typically long-stroke. In some instances, these are oriented horizontally – this is where our draw wire solution overcomes deflection issues associated with long rod-type sensors. Specifying Your SensorCPI works closely with each engineering team to understand and define the particular needs of your sensor application. While some sensors can be used “off the shelf”, we expect to fully customize and qualify your solution for you, as partners in your success. Please call our engineering team today at 973-887-9400 and bookmark http://www.cpi-nj.com Original content posted on https://www.cpi-nj.com/blog/what-can-i-do-with-my-intrinsic-safety-rated-position-sensor/ Here at CPI we’ve developed a name for ourselves when it comes to precision engineered draw wire sensors, made for harsh duty applications. Sensors like our SL1200 draw wire position sensor get the job when other sensors just don't survive.
But “harsh duty” appears to be an overused term, at least in the hydraulic linear position sensor industry. Recently some of our competitors have touted their “harsh duty” sensors in a variety of really scary(?) applications.
On the other hand, when CPI says it has a harsh duty position sensor, we have some very specific ideas about what that means.
Call us today to discuss your application. This blog originally posted at https://www.cpi-nj.com/draw-wire-sensor-heavy-duty |
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