Shell – new technology for onshore seismic
Thursday, February 17, 2011
Shell is developing two new technologies for onshore seismic – a new lightweight, low noise wireless sensor together with HP, and a fibre optic recording system, ideal for permanent monitoring, together with PGS
Shell is currently developing two new technologies for onshore seismic recording, to enable denser channel recording and permanent recording over the life of the field, said Wim Walk, manager of Shell’s geophysical measurement research and development department, speaking at the Jan 25 Finding Petroleum London forum, “Advances in Seismic”.
With HP it is developing a new wireless lightweight wireless sensor. With PGS it is developing a fibre optic land seismic recording system.
“We said, let’s see what we can do with these companies and develop partnerships,” he said.
The oil industry is tackling more and more complex and smaller reservoirs, and looking for ever higher recovery percentages, all of which means that better seismic data, which can provide a clearer and more accurate understanding of the subsurface, is a great help, he said.
It will help enable exploration in the subsalt plays in the Middle East, of which a significant part is still unlocked” he said.
It will also be a great assistance in unconventional gas operations in North America, where Shell is greatly involved.
“The future reservoirs will have more complex fluid distributions - they'll be harder to detect and to model,” he said.
“It all needs a big leap forward in seismic data quality and we need to do something about that,” he said. “We need to step up the amount of measurements and add more data to get to where we want to be.”
A cost-effective permanent seismic monitoring capability on shore would be very helpful in maximizing recovery, monitoring how oil is being extracted from the reservoir and where it remains in place. “We need to get as much as possible out.” he said.
Permanent seismic monitoring can also be used for monitoring carbon dioxide underground storage.
Shell has been looking for new onshore seismic technologies for a number of years, and decided to drive the technology development itself, because it did not see the traditional seismic industry “enthusiastically driving into that direction,” he said.
“We decided to take the initiative and said, let’s see what can be done.”
So far, both the HP and PGS projects are on schedule. The feasibility stages are nearly completed, and modeling has been done of the deployment efforts. Field tests are starting shortly. “Prototypes exist and initial tests confirm they meet the specifications” he said.
Shell is not planning to enter the seismic instrument business itself, and compete with other seismic technology providers. The technology will be developed by PGS and HP, with Shell in the driving seat.
Both HP-Shell and PGS-Shell partnerships plan to invite a traditional seismic provider to partner in the commercialization phase, although there will initially be a period where Shell will have exclusive use of the technology.
“We are not planning to keep the technology to ourselves,” he said. “In the end, the whole point is to drive the industry forward in this.”
The biggest limitation on current seismic technology is the crew size. There are limits to how large a seismic crew can practically be. Current seismic crews can already involve 200-300 people and involve 500,000kg of equipment.
“We can't just multiply the system we have by a factor of 10 - we'll have 2000 people out there, that's just not acceptable,” he said.
Crews spend most of their time moving equipment, so if you want to get more channels of recording for the same number of crew, you need to reduce the weight of equipment per channel.
“We identified two technologies with the potential to increase the channel count but keep the deployment effort essentially the same.”
The technologies will ultimately stand or fall by whether they can be feasibly deployed.
Shell has done modeling to see how easily the systems can be deployed, both computer modeling and small scale real modeling with dumb units in the desert,” he said. “It can be done if these things are lightweight, with an effort that is the same as we currently make.”
Being able to shoot and record seismic at lower frequencies would help improve the subsurface understanding.
“Now we're shooting data to 7, 8 Hz and processing it, but we need to move downwards in frequency,” he said.
“We know that there will be a huge quality difference if we can go even further. If we can go to as low as 1 Hz that would be phenomenal.”
With IT giant HP, Shell is developing a new wireless unit to record, store and transmit seismic data.
The most important component of the unit is a sensor which has a wide bandwidth and dynamic range, low noise, low weight and low power consumption.
Because it has a low power consumption, it does not need such heavy batteries, and because it is wireless, it does not need any cables.
As a result, the weight of equipment which has to be carried out to the field is much reduced, so less manpower is required for the same number of channels. This all makes a much bigger number of channels more feasible.
Shell is aiming to develop a system with HP which can feasibly record a million channels in the field. “Although you don’t always have to put out a million channels out there, of course,” he said.
The sensor was originally developed for a high density storage device. The sensor is built in HP’s Microelectromechanical system (MEMS) technology for HP’s ink jet printer heads. Shell found out about it when it invited HP to an internal conference on new developments in nanotechnology.
“When we first saw the MEMS sensor we were not sure that it could serve as a seismic sensor. But there was a program and project to modify the sensor, to see that it actually works,” he said.
The sensor is packaged into a unit which includes a sensor, a battery, wireless communications, electronics, and a pin to pin it into the ground. It is strong and lightweight.
Managing a million channels of wireless communications from all the sensors is also a big challenge. “But a company like HP is well positioned to deal with these challenges,” he said.
HP has a very different culture to Shell, in particular because it is used to working to much shorter time frames – HP works in time frames of a few months between the latest technology launch, Shell thinks in time frames of decades, he said.
“You have two different business cultures which is both challenging and exciting. So we are very happy with the way things are going,” he said. “It’s interesting and rewarding how you can synergize both companies’ capabilities.”
Shell is working with PGS, to adapt its fibre optic permanent ocean bottom seismic recording technology for use on land.
The sensors do not need any electric power and the fibre optic cable that carries the data from the sensors can be much lighter. This reduces the weight of the total system, which means that it is easier and faster to deploy.
For example, one optical fibre cable could carry 4000 channels, so you can have a seismic line 40km long with sensors every 10 metres. You have a very dense and large system that doesn't need any electric power in the field,” he said.
“We have established that it fits the bill in terms of noise, frequency response and weight. This system has very interesting advantages, options and possibilities.”
Another important technology development is the growth of computer processing capability.
Until about 2010, the size of a seismic survey was limited by the cost of computer processing capability, he said.
But in 2010, the price of computer processing capability reduced to the point that the limiting factor in size and density of seismic surveys was the number of crew you could deploy in the field and the amount of equipment they could carry.
“We want to re-claim the advantage of this computing capability,” he said.