Statoil’s chief researcher for petroleum technology, Dr Øivind Fevang, discusses the company’s ambitious recovery goals and what part EOR has to play in achieving them
Dr Øivind Fevang has an exciting, if perhaps unenviable, job. As Statoil’s chief researcher for petroleum technology, he aligns Statoil’s R&D portfolio, with the demands of the company’s business units and production licences.
It involves finding solutions to the myriad challenges of the company’s diverse operating regions, from new fields within the Arctic Circle to the offshore heavy oil development in Brazil and the tight oil in the US’ shale plays. Closer to home, work on the Norwegian Continental Shelf (NCS) poses some interesting complexities: although many producing assets are now reaching late life, Statoil is also bringing new field development projects on line.
Statoil has an ambitious target of reaching an average of 60% recovery on its operated licences on the NCS. Reaching this ambition with value adding barrels requires hard work.
There are four pillars in Statoil’s strategy to maximise recovery from the offshore assets:
Safe and cost-efficient operations
Reduce drilling and completion cost and time
Improved technologies for reservoir monitoring
IOR techniques to produce trapped and bypassed oil
“Many of our fields are approaching the tail end or are actually in the late part of the tail, so having an infrastructure and topside facilities which are efficiently run and cheap to maintain is a key issue in order to produce the last barrels,” Fevang says.
Reducing drilling and completion cost and time is vital in order to reach the company’s IOR goals. Time and cost spent on plugging wells is part of this picture. Over the next years, the well construction processes will be improved by implementation of automated systems. This is paramount for improving the company’s drilling and well construction process and a prerequisite for increased and accelerated production.
Improving the recovery will be achieved by locating undrained or partly drained areas and by mobilising trapped oil.
Geophysical reservoir monitoring plays an important role in locating areas with potential for additional recovery. 4-D seismic has assumed a significant role in finding new drilling targets for the last 20 years. On the Gullfaks field alone more than 20 wells have been drilled based on 4-D seismic and these wells have contributed to more than 64 million barrels of additional oil. Seismic cables for permanent reservoir monitoring have now been installed on two of Statoil’s fields (Snorre and Grane) to get a more detailed understanding of where the undrained oil is located.
Enhanced oil recovery
As with almost every oil-producing region, water injection forms the backbone of Norway’s recovery technique. Years of refinement mean that water flooding is “very efficient” here, but gas injection has also played a significant role in the impressive oil recovery achieved on the NCS.
In addition, chemical EOR is also an important focus of the R&D portfolio. Fevang outlined recent work in polymer flooding, while other projects had used water diversion techniques to raise production from permeable reservoirs. One such recent example is the water diversion pilot with Silica gel on the Snorre field.
“We think it is the more conventional offshore, heavy oil reservoirs which present the largest target for chemical EOR methods when it comes to polymers,” he says. The company is now looking at implementing some of these techniques in early stage development of Norway’s newest giant field – Johan Sverdrup.
The giant Johan Sverdrup field – holding reserves of between 1.7 and 3 billion barrels of oil equivalent, and where these pilots are evaluated – presents challenges. “We need polymers to be very sustainable and not to break down over longer times at harsh conditions. Onshore, the main well spacing is far below 500 metres – and we’re talking about extending it up to 5 km for Johan Sverdrup,” Fevang noted.
Back to basics
There is a tendency to consider EOR as a number of set techniques which can enable operators to produce more oil, but this is perhaps a narrow-minded view. Across its operations, Statoil considers the process of improving and enhancing recovery more holistically, from “new drilling techniques which enable us to create extended and far-reaching wells,” to standardised subsea infrastructure. The latter aims to create “plug and play” solutions, akin to the architecture of computer peripherals, with the intention of reducing costs and encouraging more co-operation.
In this sense, he adds: “Statoil is focused getting the cost down and on value barrels; because if we get the costs down we will get the barrels.”
So are there any technologies the industry is missing out on? “If only I knew which technology is overlooked!” he exclaims. “We are constantly looking for any potential game-changer within the entire IOR value chain. In 2014 we opened a new IOR laboratory focusing on fundamental understanding and developing new IOR technologies.”
IOR has a high focus in Statoil – even in a period of relatively low oil prices. The company’s R&D programme within IOR is strengthened and the co-operation with the world leading universities and research institutions re-enforced.
And as a final note, he says, “Technology is essential, but more than technology is required: i.e., a systematic and continuous effort to identify, evaluate and implement EOR measures.”