Each site is unique and the challenges each project faces is different, more often comprising multiple stakeholders and influencers bring together an array of skills, expertise and equipment to aid project execution.
For over 40 years P&B have been closely engaged with the major Oil & Gas operators and engineering procurement and construction businesses (EPCs) in supply and support of these projects over their entire lifetime.
Electrical networks designed for oil and gas sites are complex and highly dynamic systems which are fully integrated to the process control operations of the plant.
The modern protection relay is very much a key enabler of these control systems, and extends far beyond its function in providing electrical protection. The relay is responsible for behaving as a data gathering hub within the switchgear, acting as a permissive control logic device and most commonly communicates over a variety of protocols to provide critical feedback for near-immediate decision making at the control system.
Arguably P&B’s modern relay technology platform ‘Vision’ was born out of this environment and earlier experience, influencing the design, specification and the modularity of the products which we manufacture today.
Continue reading our case studies to understand how P&B have been involved and able to enhance these types of projects.
Jamnagar is the largest petrochemical complex in the world, processing imported crude to multiple derivatives for the entire Indian sub-continent.
The summer ambient conditions in Jamnagar’s sub-stations proved to be the most challenging environment modern P&B relays have ever faced.
At the end of the 90’s when ‘Vision’ was first introduced, Jamnagar’s electrical system required almost 4000 protection relays. Unlike the electromechanical Golds relays which would be quite comfortable in all manner of harsh environments, a high ambient temperature and additional heat rising through the motor control tier meant uncomfortable conditions for the sensitive electronics of P&B’s new relay.
As a result of Jamnagar the mk1 relay design was replaced with the mk2 which has further evolved into today’s production. The relay now incorporates a host of heat dissipation and anti-heat generating measures within the relay design, at a hardware level and aided within the product software. These defensive measures have benefitted our entire platform design, not only improving the relays tolerance to heat but to improve the electromagnetic compatibility (EMC), making the relay more robust and suitable for a wider variety of critical applications.
Accumulating return statistics now measure the product’s mean time between failure (MTBF) well in excess of 100 years.
The Elgin PUQ (process, utilities and quarters) and the Franklin satellite are jack-up platforms in the North Sea producing gas and condensate from one of the world’s highest pressure and highest temperature well fields.
The Elgin and Franklin are 5 kilometres from one another and connected via a sub-sea cable. P&B was selected for the primary protection system on the 13.8KV, 6.6KV and 415V switchgear.
The automatic transfer system, or automatic changeover, was required for each of Elgin’s switchboards equipped with two incomers and a bus coupler. P&B achieve ATS or ACO with the use of Advanced Feedervision Relays for overcurrent, earth fault, under and overvoltage protection as well as check sync with in-built logic for full automatic transfer on loss of an incomer and automatic restoration upon the upstream supply becoming available again. This transfer system – redundancy approach helps maintain the availability of the power supply to the process boards and those responsible for utility feeds – even under a faulted condition, or allowing maintenance to be performed without reducing the capacity of the plants production. This is particularly useful in a platform situation where the electrical system is islanded and reliant entirely upon its own power generation.
In addition to the ATS standard scheme P&B also implemented special changeover systems for the main generator auxiliaries’ switchboard and at the incoming end of the Franklin sub-sea feed which was additionally equipped with a back-up diesel generator. This would auto-start on loss of the Elgin link, powering the platform, then reclose and auto-stop the generator once the subsea feed was re-energised.
Petroleum Development Oman is the state owned exploration and production of the Sultanate of Oman. The onshore wells are dispersed across the interior of the Sultanate.
The ability for intelligent motor reacceleration controlled by the motor protection relay was a key part of the electrical specification within PDO. Although motor reacceleration in its basic form simply means the motor will automatically restart following a short power outage, there are in reality many scenarios to consider.
Normally within a motor control duty, the auxiliary power supply to the relay is derived from the bus bar voltage, hence losing power no just to the motor but also the controlling device. So the relay must be equipped to cope with ride through in the shortest of dips and storage and retained memory in the event of longer outages. Equally when power is restored a sudden attempt to restart all motors would create another overload on the system with the potential to cause wider instability and prolonging a temporary outage into a major plant wide shutdown, with significant economic effects.
Within the Motorvision software, the flexibility of the re-acceleration settings allows the relay to be easily programmed to perform precisely against the requirements of any particular client.
Humber Refinery is one of the largest refineries in the UK. Originally built in the late 1960’s it has changed owners and has been extended and modernised over its long history.
As a result Phillips 66 must maintain a whole host of differing equipment from all manner of manufacturers on its plant.
As an extension to having previously used our new relays for retrofitting of older P&B relays at this particular site we were asked to undertake a feasibility of replacing another manufacturer who has recently withdrawn support of an older relay used extensively.
The existing protection relay was housed and integrally fitted within the manufacturers’ withdrawable switchgear cubicle, the available space was already limited and the opportunity to alter the design substantially would have proven too costly.
P&B rehoused their standard protection relay parts within a shallower case more similar to the oems. The integral CTs were tested for linearity and an input attenuator circuit was designed to interface to the oem CTs which would remain fitted in the starter tray. A very simple adaptor plate was designed to carry the new display. The existing wiring loom and terminal positions differed greatly from a standard P&B relay. An interface pcb was needed to translate the P&B terminals into the same format as the original relay so that there would be no wiring changes need.
The solution was created, a pin for pin, mechanically similar protection relay, which was of a present day design (by virtue of standardised P&B relay modules) from the ‘Vision’ range with the benefit of onward support and serviceability for the client.
As a global operator BP has a huge number of assets of varying ages and origins. In the UK many of those assets are offshore in the North Sea. And as is the case with many large scale capital assets they are still required to operate fully despite reaching and being beyond the original anticipated life time.
The Schiehallion and Andrew assets, amongst others, were first commissioned many years ago with much earlier vintage P&B protection relays. As the OEM (original equipment manufacturer) P&B were approached and asked to help upgrade the electrical system to a more modern and maintainable standard. This involved replacing the older equipment with new, allowing the client to inherit newer features such as communications.
Of course the newer relays were in no way similar in size or shape to the original devices. However, having retrofitted systems previously and understanding the complexity and time scales required to do so, the available shutdown period of a North Sea oil rig did not allow sufficient time in a single trip to undertake the entire workscope.
P&B thus created electrically and mechanically compatible devices using the Vision relay technology, effectively a new relay packaged in a format to suit the retrofit requirement. This made the actual process of retrofitting much simpler and faster.
The interaction with BP was largely responsible for creating the P&B range of retrofits for legacy and previous generation protection relays.
P&B is a leading UK innovator of electrical protection, safety and control technologies.
Our specialist expertise and unrivalled experience is relied upon in heavy industries throughout the world to ensure the highest levels of safety and performance.