Carl Pilmer, Global VP, IWOCS, Field Technology Services, Proserv, explains how controls technology is set to transform subsea well interventions.
Through the lifetime of a subsea field, intervention workover control systems (IWOCS) represent an integral piece of equipment. On the one hand, IWOCS enable operators to undertake a myriad of well interventions when required, while, on the other, original equipment manufacturers (OEMs) can use the systems to land the subsea tree and subsequently bring a well online.
At Proserv, in the North Sea for instance, we typically utilise IWOCS for interventions such as well stimulation, chemical injection or controlling valves to shut down production while wireline logging operations are undertaken down the open wellbore.
For operators, it makes perfect business sense to have an IWOC umbilical on standby, ready to go and compatible with the various interfaces into the tree, so the system can then be used for any manner, or number, of interventions during the entire period the well is in production.
Ask any operator what it prioritises from its IWOC system, and its supplier of choice, and it will invariably emphasise the need for safety - a secure environment for the service technicians on site to operate in - as well as speed of response, so that when remedial work is required, support is available quickly and it is conveniently accessible within the local region.
But the reliability of the equipment, while always a crucial factor, has become ever more important for operators as they continue to adjust to a conservative investment model since the industry began emerging from the challenges of 2014-2015 onwards.
You can understand why. If an operator steams out into the North Sea in a vessel for several days to the West of Shetland, shipping vital IWOCS equipment, only to see it fail, then it has had a very costly and frustrating journey, with its on-going issue still unresolved. So, with efficiency at the apex of requirements, IWOCS suppliers such as Proserv need to provide extra reassurance to its customers.
Applying controls technology
As a controls technology company, we naturally believe developing a form of “smart” IWOCS is the way forwards. If an IWOC system incorporated enhanced monitoring technology, then there would be major benefits for both the operator and the supplier.
Increasingly, IWOCS are taken on a lease basis as such an arrangement avoids the need for a major initial lump sum investment and provides the sort of flexibility attractive to cost-conscious operators. By integrating controls technology, it would be possible to generate detailed service logbooks so that any prospective customer could assess the equipment’s previous usage and wear and tear.
It would be feasible to catalogue all operations carried out by the IWOC system. For instance, in deep water, there could be 21 different hydraulic lines in the umbilical. But, via the development of smart IWOCS equipment, the supplier would have the capability to tell the operator, at any time, which specific hoses in the umbilical had been used, what levels of pressure they had experienced, how many times they had been deployed and retrieved, had they been clamped correctly – the narrative behind that one umbilical would be extremely detailed.
There would be further additional benefits from smart IWOCS. By directing fibre optics down the umbilical itself, it would be possible to gauge temperature readings. This would be valuable when the IWOCS equipment was being operated in shallower waters, as a significant length of the umbilical might simply be heating up, as an electric coil, lying on the deck of a vessel. So, temperature monitoring could help prevent damage and would significantly enhance on-board safety.
Being able to draw such a picture of how an IWOC umbilical had been utilised would also enhance the potential leasing model, again corresponding to the prevailing philosophy of moderate operational expenditure.
Some IWOCS providers have preferred to supply not only the equipment itself but also a dedicated team of personnel to operate it – increasing the prospective outlay for the customer.
But the advent of smart systems would allow the IWOCS specialist to rent out the equipment separately, as the supplier would be able to assess how the operator’s team had used it once it had finally been returned. This would negate the necessity for personnel to be deployed and so the investment required by the customer would be reduced accordingly.
Implementing controls technology is the future direction for IWOCS. By connecting to an offshore facility’s virtual private network, it would be viable for the supplier, as well as the operator’s subsea control managers and IWOCS technicians, to monitor the umbilical in real time, hundreds of miles away, assessing how it is performing and what it is doing.
There is no question the extra reassurance provided by detailed service logbooks and the close monitoring of the IWOCS equipment’s performance would be a very attractive package for operators wanting to steer clear of costly downtime and potentially unreliable kit.
Market analytics undertaken by Proserv suggests that the way forward for the subsea segment is into increasingly deeper waters. By 2025, we estimate that more than 400 new subsea wells will have come on-stream over the previous ten years at depths greater than 600 metres. Wider industry experts also see a compound annual growth rate of 3.9 per cent in the installation of subsea trees below 600 metres across the next four years. These are exciting opportunities for operators and service providers alike, but they also represent ever-greater challenges for the equipment required.
Umbilicals may have to withstand pressures of up to 20,000 pounds per square inch in very deep water and so knowing that their IWOC system is reliable and able to be assessed every step of the way, via controls technology, would instil greater confidence in the operator.
Whether it is in the deep waters off West Africa, or supporting a decommissioning project in the North Sea, the challenge for independent IWOCS specialists like us is to generate cost-effective and disruptive innovations, such as smart IWOCS.
Our goal is to encourage operators to make a smart decision of their own, by choosing the best in class option for the whole life of the field and not just relying on a standard IWOC system delivered alongside the subsea tree.