Stop waiting for multicomponent technology to arrive - it already has.


The oilpatch is littered with fabulous technologies that nobody uses. There can be many reasons for this, but almost always the major barrier to a technology becoming commercially viable is cost. If it provides a better service but costs 10 times as much as the existing technology, it's not likely to move past the pilot project stage for many, many years.

Until fairly recently multicomponent seismic fell into this category. The potential benefits of the technology, which measures shear as well as compressional (P) waves, reads like an explorationist's wish list - it can see through gas chimneys, distinguish different types of fluids, better characterize lithology, etc., etc. What it couldn't do was compete with conventional P-wave data on a cost basis.

But the introduction of new acquisition systems by Input/Output (VectorSeis System Four) and Sercel (408-DSU) has resulted in a quiet revolution, at least in the land market. The systems are purpose-built for full-wave imaging and use digital accelerometers based on micro electro-mechanical system (MEMS) technology. The result is an efficient system that is comparable to conventional systems in terms of its deployability yet records three times as much data.

Currently two companies, Veritas DGC and Trace Energy, are using the systems in North America. Veritas has partnered with Sercel, and Trace with Input/Output (I/O), to make multicomponent technology commercially available to oil company clients. Acceptance has been slow but steady.

Benefits

Acceptance is likely to accelerate if the early surveys can be shown to result in increased ability to solve tricky subsurface problems. At press time, those results were still pending. But companies like Apache Corp. are banking on the technology to better image some of their tough fields.

"We looked company-wide at some land examples that would benefit from multicomponent," Mike Bahorich, executive vice president of E&P technology for Apache, said. "We found one play in Canada that's a fractured carbonate, and we were interested in getting information about porosity and permeability sweet spots in the carbonate. In another area we have shallow channels, and a gas-charged, good-quality sand can produce 3 MMcf/d, while a poor-quality reservoir might produce 50 Mcf/d. We're hoping to use multicomponent seismic to help distinguish higher quality reservoirs."

Basically shear wave data complements P-wave data by providing an independent constraint on the subsurface information. "There are three components that go into extracting rock properties from seismic - the P-wave velocity, the shear velocity and the density," Brad Bankhead, vice president of reservoir technologies for Veritas, said. "The problem is that P-wave data gives you information about the P-wave velocity and, in a roundabout way, the shear wave velocity, but it's very difficult to decouple the density information out of the data. The hope is that by having direct information about P-wave and shear wave velocities, you'll be able to extract density information that allows you to start separating things like lithologies - sand versus shale - or even water saturation and gas saturation."

But the learning curve is still quite steep. While the new systems have made the acquisition process easier, processing takes longer, and interpreting the data will require a different skillset than the interpretation of standard P-wave data.

"Multicomponent technology today is not a silver bullet," Deanna Goodwin, president of Veritas DGC Land Inc., said. "In the cases we're seeing, it's more of an additive product. One of the analogies is that conventional data is like a black-and-white photograph, and when you add multicomponent to it, you don't replace the photograph - you add color."

Making the business model work

Veritas management has embraced the multicomponent concept and is encouraging its different business units to work together to provide an integrated offering. In addition to acquisition, it offers processing and interpretation services to its clients.

"My view is that we don't build a multicomponent business by merely focusing on acquisition," John Gibson, director of emerging technology for Veritas, said. "We build a multicomponent business based on the value that's created for the client using the new information. That of necessity requires an integrated effort among interpretation, processing and acquisition, and Veritas is focused on such integration."

Goodwin added, "If you hand the clients a raw section of data, unless they have all of the tools, they can't really get the value out if it. At this point most of the data isn't something you load and interpret off the workstation. The tools have to be developed, and we're working on developing them."

She added that Veritas' purchase of Hampson-Russell Software a couple of years ago was partly motivated by the desire to incorporate that company's multicomponent interpretation package into the Veritas product offering.

The company has shot more than 50 surveys and has processed an even larger number to date. Some have been tests, but many have been commercial products. "We feel like we've stepped away from dabbling in technology to doing something that people are willing to try," Goodwin said.

A method that's becoming successful for Veritas is the concept of "embedding" a multicomponent survey within a larger traditional survey, Gibson said. "A lot of people want to know if the technology will work in a specific area," he said. "We suggest that, in the area where they have a P-wave survey, they should think about embedding a multicomponent survey with the intent of seeing what the data quality is like, what the sampling requirements are, and being able to assess in their own backyard whether this new technology is going to add value."

Trace Energy has forged an alliance with I/O to give it a competitive advantage over other companies that don't have access to multicomponent technology. As a result, Apache, which has a technology relationship with I/O, is now a Trace client.

Trace does not do its own processing, but Dave Smiddy, vice president of finance and general manager of Trace, said the company is hoping to set up a strategic alliance with a processing shop that specializes in multicomponent data.

Bahorich said that Apache is using a variety of processing shops for its multicomponent surveys but relies on I/O itself for much of the work. "We've employed a number of other vendors, but the one company that will be looking at everything is I/O," he said.

Remaining challenges

Will there be a time when multicomponent acquisition is the rule rather than the exception? Possibly. But it won't be any time soon.

A particular hurdle comes in the processing stage. Bahorich explained that in conventional P-wave processing, the common reflection point can be assumed to be roughly halfway in between the source and the receiver. In shear wave data, that point is asymmetric.

"You have to account for that in processing," he said. "Most of the multicomponent work to date has been done in relatively flat areas for that reason."

It also will take time to learn how best to use the data in areas with complex structures, he said.

Steve Roche added, manager of emerging technology applications for Veritas, "Upcoming shear waves are typically very distorted by the near surface. There are a set of standard procedures evolving for handling that. Different companies will do it different ways, but with the new acquisition hardware we're able to get much better spatial handling."

Meanwhile those companies willing to take a chance are giving the new technology a test drive. "A lot of companies are looking at multicomponent data as a hedge on the future," Tim Carry, technical supervisor for Trace, said. "The incremental cost in acquisition is very small, so they're acquiring the data to have in their libraries so it's there when they need it."

Goodwin added, "In this environment, especially with environmental sensitivity continuing to grow, I can't imagine an oil company that would shoot a conventional 3-D survey, wait for multicomponent technology to mature and then reshoot something they've already shot. The cost of access is so high. I feel like the advent of the technology in its final form is so close that oil companies really need to take a second look."