Q&A: Ears go in the ground to aid fracturing

Hydraulic fracturing has opened up a bonanza of new activity in oil and gas, but as natural gas prices have stayed low, the pressure has intensified to make sure that drilling produces results.

Companies that once focused on acquisitions are searching now for ways to get better performance from the wells they already have.

Hydraulic fracturing involves injecting fluids and sand under pressure into a reservoir to break shale or other dense rock and release trapped oil and gas.

Houston-based MicroSeismic uses instruments called geophones on the surface or buried underground to capture and analyze sounds from a well while it’s being fractured. The technology, called surface microseismic, allows operators to customize the fracturing while it’s in progress, improving the efficiency of the resulting hydrocarbon extraction.

Peter Duncan, founder and CEO of MicroSeismic, spoke with the Houston Chronicle about the technology and how the industry is using it. Edited excerpts:

Q: What challenge in hydraulic fracturing is MicroSeismic addressing?

A: In hydraulic fracturing, operators try to create flow by putting in fluid and cracking rock. You can think of the rock as being underground and in a vice, with certain zones of weakness in it. Thousands of feet below, you don’t know which parts of the rock broke when you pumped the water in. You have a long horizontal well and you pump the water in to create those fractures, but you are kind of blind as to what is going on down there.

When those faults and fractures open up and they split, it makes a snap, crackle and pop. The geophones we place allow us to hear those snaps and to locate where they took place in time and space. We can then translate that into an image where the engineer can see those fractures. From these sounds, we can make a picture of what is going on in the reservoir.

Q: Why is this information valuable for operators?

A: It can tell an operator where the reservoir is draining and what part of the reservoir he doesn’t need to worry about. Knowing both of these things can tell him where to put the next well. If he drills too many wells, he stands to lose his profit. If he doesn’t drill enough wells, he leaves hydrocarbons behind, so this information is extremely valuable.

In the old days, operators would do tests on a couple of wells and develop a formula from those tests for all the wells in a field. But we are finding in the shales that the rocks are not as uniform over huge areas. With this technology, you can watch the fractures grow in real time, which allows operators to plan the next increment of fracturing. If you can save one stage, you might save $300,000 on a single well.

Q: How popular is this kind of well monitoring?

A: Most of the industry knows about microseismic monitoring, but if you look at what percentage of wells get monitored, it is something like 5 percent. It was first introduced in the 1970s but didn’t really come into its own until the 2000s. In 2005, only half of 1 percent of wells were monitored, but over the last 10 years, it has increased by an order of magnitude.

If you accept the fact that without the monitoring, you are fracking blind, the question becomes – why wouldn’t you monitor every well? Our mission is to make monitoring become as key to fracking as logging a well is to conventional well production. If you don’t log a well, you don’t know what’s down there. You need some other set of eyes down the well, and we are the set of eyes.

Q: Who are your customers?

A: Our primary customers historically have been the independent operators, who were the first to go into the shales and took the risk to develop this kind of technology. The major companies have been less involved until more recently. But our client base ranges from small clients with one well to major companies with thousands of wells.

Q: What is the next challenge for the microseismic technology?

A: It’s finding the best ways to interpret the data and integrate it with other types of information. We get a lot of data, but we don’t quite understand how it all fits together. When we listen to the data, we can tell where the rock broke with accuracy of tens of feet, when the rock broke with accuracy of a few seconds, and how the rock broke. We can tell whether it broke horizontally or vertically – whether it parted like the Red Sea or like splitting a piece of wood. Where we think the opportunity is, is in extending that to a detailed understanding of how that pattern of breakage of the rocks is going to translate into production of hydrocarbons.