Brief article on adaptation of a spying tool to use in the oil/gas fields

http://www.bloomberg.com/news/2013-06-24/frack-music-attracts-halli...

Excerpts from the link:

A gossamer-thin glass line threaded two miles underground is allowing oilfield engineers to listen to a new kind of music: the sounds of fracking.

Halliburton Co. (HAL) and competing providers of drilling gear are adapting acoustic spy technology used by U.S. submarines to record sounds made deep in the earth that can guide engineers in finishing a well and predicting how much oil will flow.

The technology is targeted at an estimated $31 billion that will be spent this year on fracking stages that yield less-than-optimal results, a majority of the work at 26,100 U.S. wells set to be pressure-pumped in 2013, according to PacWest Consulting Partners LLC.

Energy companies are fueling the booming business of so-called distributed fiber-optic lines, where the cord itself is a sensor for sound and temperature throughout its entire length.

One fracking stage can cost about $100,000 and a typical well now will have about 15 stages, said Alex Robart, principal at PacWest. The effectiveness of each stage varies wildly. The industry generally subscribes to the 80-20 rule, meaning 80 percent of North American production comes from about 20 percent of the fracking stages, he said.

Contractors ranging from Halliburton to Exiius LLC have begun permanently installing fiber optic lines in U.S. wells. During completion of a just-drilled well, the fiber can listen for subtle noises that suggest sealing the well with cement didn’t work properly.

Then the fiber can listen for good and bad fracking stages, and finally it’ll be able to confirm if oil and gas is flowing. Eventually they’ll be able to actually measure production flow based on sounds, McColpin said. He compares it to a flute: as different holes in the well’s casing are open or clogged, the sound pitch of fluids flowing through the well are affected.

Programmers also are working on algorithms to detect the difference in sound for water versus oil flowing into the well from surrounding rock. Then valves for different areas in the well bore could be opened or closed as needed to minimize water incursion, which is a waste.