Andrew Dykes sat down with Well-SENSE Technology founder Dan Purkis to discuss FLI – an entirely new and disruptive approach to well intervention
Building equipment that can survive downhole is hard. Dan Purkis is quick to remind me that “people think designing rockets and spaceships is difficult, but that’s nothing compared to downhole tools!” Indeed, that simple truth alone adds years to development timelines, millions of dollars to budgets, and keeps service prices high. Purkis thinks that needs to end.
His solution is to use disposable tools that do not need to withstand the downhole environment – at least not for long. “One of the huge problems at the moment is the cost of the current solutions,” he explains by phone from Aberdeen. “The products and services that are offered are too expensive for the current market. That represents a huge opportunity to try and solve the problems using alternative technologies.”
Engineers spend years designing rental tools that must have long term high temperature reliability whilst being both serviceable and robust. It takes years to train engineers to be able to design to this level and it takes years to build, test and qualify such tools. “A tool has to be really reliable, corrosion-resistant, pressure-resistant, heat resistant etc., and all that means the designs become very complicated and take a long time to come to market,” he continues.
The solution, in Purkis’ words, is “a new discipline.” The Fibre Line Intervention (FLI) concept is a range of dissolvable intervention tools, deployed into the well on a single fibre-optic cable, which could replace or compliment thousands of intervention operations – from perforations to pressure, temperature and flow sensing – all performed faster and at a far lower cost than the industry is used to.
Purkis is no stranger to designing downhole tools. Having worked at Petroleum Engineering Services (PES), a company which pioneered some of the first intelligent completions, before being acquired by Halliburton, he went on to found Petrowell, where he designed a suite of RFID-operated completion and drilling tools. After six years in development the technology was sold to Weatherford. His latest venture, Well-SENSE Technology, was formed in July 2015 with the aim of “bringing technology from outside of the industry and redeploying it.” Purkis believes that the sector’s risk adverse approach to innovation means it overlooks solutions to problems which have already been explored by other industries.
His method when approaching new intervention tools was to ask: “What would Google or Apple do?” The answer, he posited, was unlikely to lie in the industry’s standard trio of coiled tubing, electric line or wireline, all of which have their own technical challenges, require large surface spooling equipment and multiple personnel to operate. Ultimately the tool designers end up with a downhole product that is a “20-foot long steel rental tool; again”
Disregarding the existing systems, he instead looked to the incredible strides made in consumer electronics and materials. “No-one in the market at the moment makes disposable tools,” he says. “Because with current approach to design, it would be too expensive and you can’t leave a tool down the well.” So he set about making some.
Taking inspiration from out with the oil and gas industry, the most revolutionary aspect of FLI is its ability to be discarded. With a housing based on a biodegradable polymers and water-soluble metal alloys, the tool is used and abandoned in the well, where it dissolves in a matter of days.
This tool is deployed into the well via a surface-connected fibre-optic line, allowing the FLI tool to “freefall into the well and be left there. You don’t get it back, and it doesn’t cause an obstruction.” One of the biggest risks in standard intervention jobs is becoming “stuck in hole” – but because FLI tools never need to be recovered, this risk never occurs, meaning no costly down time or fishing operations. “This would enable production optimisation operations to be performed on wells formerly deemed technically to risky or economically unviable,” Purkis says.
As its name suggests, the key component to FLI is a fibre-optic cable. Being strong and light – typically around 0.25mm in diameter – it is ideal for connecting small pieces of downhole equipment back to the surface. In its bare format, it is also very cost effective, even at lengths of 4 to 6km, which is more than enough to reach the deepest sections of most wells. Moreover, it offers a revolution in data transfer speed. While wireline tools often employ data compression to send real time information back to the surface via copper wires, fibre optic cable can transmit data at 2.5Gb/s – more than 1,600 times greater bandwidth. That would allow users to deploy a camera tool, for example, and receive a live feed of up to 64 channels of HD, uncompressed video data.
Additionally, it requires virtually no footprint on the surface. While other systems require a truck-mounted spool of cable, 10,000 feet (3,000 metres) of fibre-optic takes up the same space as a can of baked beans. Mounted inside the FLI tool itself, it unspools as the tool free falls into the well, with a depth reading provided by a laser range finder. When the FLI tool has completed its job, the line is either cut – leaving the tool and fibre to disintegrate in the well – or alternatively the fibre optic can be recovered using a reel at the surface.
As a single-use tool, the electronic components of FLI tools do not need to be robust enough to survive prolonged periods downhole. If a typical job lasts 30 minutes to an hour, Purkis adds, components only need to be heat and pressure shielded to survive that long before they disintegrate. That means they can be consumer-grade rather than military-grade, lowering costs and allowing designers access to the latest components on the market – e.g. the latest smartphone camera – instead of limiting parts to those which have been qualified for use in a well.
An hour of typical operation means that the power demand of a FLI tool is minimal. Instead of a 600-V power supply fed from the surface – coupled to a hefty power regulator in the tool – Purkis believes that small coin-cell batteries can provide adequate power for key components – essentially a sensor, an encoder and a fibre-optic transmitter – without the need for expensive, high-temperature Lithium Thionyl Chloride batteries.
All of which also circumvents another of the service industry’s cost burdens. To mitigate against electronic components becoming obsolete service companies routinely purchasing lifetime inventories to guarantee that tools can be built and maintained without having to requalify replacement parts. FLI tools use the latest release of electronic components available at the time, with minimal requalification requirements. That represents big savings on advance purchases which may never be used.
Ultimately, these concessions to disposability allow Well-SENSE to build a tool whose raw cost is thousands of dollars, rather than hundreds of thousand. Operated by “a technician and a suitcase, rather than a 20-tonne artic wagon and four personnel,” FLI represents a radical reduction in cost from industry convention.
Purkis also explains his plans for two separate FLI disciplines: Active and Passive. An Active tool features electronics and components designed to relay information from downhole back to the surface. Passive tools use just the fibre-optic cable alone, no downhole tool, yet are capable of a number of impressive functions. These applications form the bulk of Well-SENSE’s current workload.
It is in conversation about recent advances in fibre-optic sensing – namely distributed temperature sensing (DTS), acoustic sensing (DAS) and pressure sensing (DPS) – where Purkis becomes very excited. Each technique involves sending laser light down a fibre-optic cable and analysing the backscatter to determine information from every metre along the cable’s length. It is especially useful in oil and gas operations because it can offer asset managers fine-grain detail about the status of every point in a well. DAS in particular is “the talk of town,” Purkis notes, because it enables users to identify the exact location of leaks, monitor production and evaluate fracking operations in real time. This is where Passive FLI steps in.
Because all information processing is done via surface equipment, there are no components within the downhole tool itself, allowing Purkis to use the first commercial FLIs as a rapid, low-cost deployment system for DAS surveys. Currently DAS is either installed as a permanent system as part of the well completion, or temporarily installed and retrieved by a truck mounted spooling system (similar to coil tubing and electric line). Both are expensive, largely because of installation time and/or capital equipment costs. A dissolvable FLI system would slash both, enabling DAS to be economical in a far greater number of wells.
Movement on these first surveys is promising, with trials now secured in Texas, Oklahoma and Alaska, as well as interest from some other small onshore operators. Following these, Purkis hopes to be able to take FLI-enabled DAS surveys to the wider industry.
While Purkis is bullish on the long-term potential of both Active and Passive FLI, he is aware that every FLI tool will require its own design and qualification – a Passive FLI tool used for DAS will be less complex than an Active tool used for performing a directional survey. For that reason, Active applications will be slower to develop, though he hopes the uptake will be swift following the acceptance of Passive systems. In the meantime, however, the company is seeking participation with anyone with an interest in the technology, from well operators to component manufacturers – “Anyone who wants to make this successful,” he says.
Longer term, his vision for FLI development is anomalous in the industry. He concedes that: “FLI in itself isn’t that useful, it’s the applications you can put on it like a camera or a PLT or a gyroscope survey.” Lacking the expertise (and time) to design every possible system in-house, he wants to see the FLI system become an open-source platform for other developers to use, “in the same way that a smartphone provides a platform for all the thousands of apps developed by every and anyone.” In an industry notoriously protective of IP, that is indeed a revolutionary proposition.
Well-SENSE is confident that it has only begun to scratch the surface of what the FLI platform could do, even in a welcoming industry, it takes time to qualify such a radical departure from the norm. Yet throughout our conversation, Purkis has been evangelistic about changing industry perceptions and adopting new technologies. If anyone is driven enough to drag the intervention market into the next century, it could well be Well-SENSE.