Digging beneath the subsurface
  from: Offshore Engineer
  by: Darius Snieckus
  Monday, October 06, 2008

Since its foundation in 1999, the ITF has been a mirror to the evolving technology demands of the offshore sector. And so it comes as no surprise that much of its time these days is occupied by projects ‘below the mudline’. Darius Snieckus speaks with subsurface technology manager Duncan Anderson.

For Duncan Anderson, who has been with ITF since it was formed in 1999 by the UK Oil & Gas Industry Task Force (now Pilot), there are some constants in life.

‘When offshore operators list the key challenges that they are keen to address collaboratively, you can see that really there are only a few themes that emerge,’ he suggests. ‘One is better imaging, a better ability to see the reservoir – and that’s important particularly as provinces start to get in to the second part of their life where the easy oil is out and you have to better understand the reservoir in every way possible to have any chance at knowing where the remaining oil is.

‘The second is late-life recovery, that is getting at the stuff remaining once the easy oil has been produced and what’s left is stuck in compartments and difficult to access areas of a structure. Structurally complex or compartmentalised reservoirs each sit under this heading. And the last theme is accessing difficult resources: tight gas, HPHT, low permeability reservoirs, that sort of thing.’

As with the wider industry, so with the subsurface sector. ‘As the subsurface sector continues to evolve over the years I don’t think there are going to be any new big themes that come up,’ Anderson reckons. ‘I think we are just going to get deeper in to the ones we have had for some time.’

Since its inception almost 10 years ago, ITF has been ploughing its ‘growing technology’ furrow pulled by member operators and service companies that share the Aberdeen-based organisation’s objective of ‘identifying technology needs, fostering innovation, and facilitating the development and implementation of new technologies’. Much of the collaborative work stems from North Sea demands, but increasingly there has been ‘clear steer’ from its membership toward aligning projects with best-inclass global technology strategies.

Last year ITF had a hand in no fewer than 16 project launches, valued at £4.5 million, while shepherding 28 ongoing technology ventures worth a further £12 million. Seven new technologies were spun out of this development work and commercialised in 2007 alone. In the subsurface technologies division, 14 joint industry projects (JIPs) are on its books currently, along with another nine projects classed as ‘under development’. Three of the JIPs deal with reservoir and wellbore geomechanics, six with high-resolution imaging, two with lowperm reservoirs and one with structurally complex reservoirs. Each, in its way, also deals with compartmentalisation.

‘Structurally complex reservoirs was a theme that had been running for several years. Now it has grown into compartmentalisation, which is a key issue these days. Many of the big reservoirs in the North Sea, Middle East, off Mexico, wherever they are, are not big tanks of oil, of course: they are made up of compartments, sometimes connected, and knowing what you are dealing with in developing a field from the beginning of production through to its late-life is key.’

Sponsored by BP, CoP, ExxonMobil and Total and being run out of London’s Imperial College, the ‘Improved simulation of fracture reservoirs’ JIP is one among many projects that is attempting to provide part of the solution to compartmentalisation. The aim of the £360,000 JIP, due to be concluded next January, is to develop a software that will upscale results from discrete fracture models to field-scale simulation of fractures, with the added functionality of being parallelised and extended to threephase flow field scenarios.

Another recent JIP, supported by Total, StatoilHydro, ExxonMobil, Eni, Chevron, BP and Shell, and headed up by Rockfield Software, is looking at devising ‘a computational framework for prediction of the initiation and evolution of fractures and faults’. Valued at £182,000, the project recently wrapped up its first phase having delivered ‘greatly improved’ models for rock formations postfracture or fault formation, touching on issues ranging from prediction of sand face behaviour through to the incorporation of geomechanics into geological reconstructions.

Fractures and faults

‘Discontinuities, manifested as fractures at the wellbore scale or faults at the reservoir scale, have a pivotal role in the physically observed behaviour and the reservoir management strategy,’ underscores Anderson. ‘However, while prediction of initiation and subsequent evolution of fractures or faults is essential for accurate geomechnical modelling, rigorous formulations that address this issue are not available in commercial code.We have now developed that commercial code.’

By far and away the most ambitious JIPs under way under the aegis of ITF today are two being run with OHM and Imperial College that aim to produce maps that provide more accurate targeting of hydrocarbons through the use of integrated geophysics. Based on joint acquisition, processing and integration of seismic and non-seismic data and improved reading of shear waves, the £2.5 million projects are receiving financial backing from 11 companies, seven of which are ITF members, three non-ITF, and the UK department for Business, Enterprise & Regulatory Reform, with additional business support from OHM.

Some £2 million is being devoted to the another chosen ‘theme’ at ITF – tight gas – with five separate JIPs now on track to improve knowledge of low permeability reserves and maximised recovery. ‘Tight gas is a case where we are trying to provide underpinning knowledge of an area that is seen as very significant to the global oil and gas industry. It is an issue on the Northwest European continental shelf but not anything like the size of an issue it is in North America. So among the collaborators in this area are the Colorado School of Mines and the Sandia National Laboratories in New Mexico,’ offers Anderson.

The JIPs include work on 3D imaging, testing and modelling of pore networks and multiphase flow in tight gas formations, simulation of fracture treatments for tight gas reservoirs, and a study on the petrophysics of tight gas sands. ‘Because tight gas is not typically easily accessible due to the tight nature of formations and low permeability and is therefore not considered economically feasible to produce, it has become an important focus for ITF and its members,’ he says, ‘And such was the level of quality proposals we received that it led us to launch five separate JIPs.’

‘Industry led and demand driven’, as Anderson underlines, is the creed of the not-for-profit ITF as it targets those technology ideas that will ‘really benefit’ the industry.

‘Our job is to implement a technology, not to spend money on JIPs. It is to make sure JIPs work efficiently and that a commercial product comes out in the end,’ he reasons. ‘In the case of the subsurface this product is usually knowledge, an algorithm or a piece of software perhaps.’ To-date, ITF has delivered over 115 JIPs underwritten by some £32 million, of which ‘something like half ’ come under the subsurface banner.

‘In the subsurface and as whole, what ITF provides is not a means of setting up JIPs, because almost anyone can do that, Anderson concludes. ‘I see our function being to challenge operators and service companies to be more innovative, not just to develop technology that will be another piece in the jigsaw. Something bigger.’OE

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