Hydraulic fracturing, or fracking, is a very expensive guessing game. Drilling companies hope military-grade fiber optics could help make the ecologically controversial practice more efficient. Businessweek reports.
Drilling companies often fire the mixture of chemicals, sand, and water more or less blindly at rocks that hold oil and natural gas to create fissures and extract the seeping fuel.
To find and measure a bedrock fracture, microseismic sensors in a nearby monitoring well track subtle earth movements as the rock cracks.
Fracking each well takes 15 stages of mixture-firing, costing about $100,000 each. Yet success is difficult to determine: 80 percent of North American production comes from about 20 percent of the stages. This year alone, drillers will spend $31 billion on possibly sub-optimal fracking stages across 26,100 wells in the U.S.
To improve that, oilfield services companies like Halliburton are testing fiber-optic cables that are used in U.S. submarines:
These so-called distributed fiber-optic lines record sound and temperature along their entire length. With steel-encased lines clamped between fracking wells and rock, drillers can record sounds that signal the perfect frack.
- Software converts the sounds to a graph, showing how thoroughly the rock is fractured.
- The fiber can pick up subtle noises that indicate when the cement sealing of a spent well isn’t working -- a safety threat that could allow residual gas to reach the surface and trigger an explosion.
- Eventually, drillers will be able to measure production flow based on sounds.
- Algorithms could detect the difference in the sound of water versus oil flowing into the well. That way valves for different areas in the well could be opened or closed as needed to minimize water.
Installing the fiber can cost several hundred thousand per well. Halliburton contractors are already using sensory cables, and with the world’s largest oil and natural gas producers testing these lines in fracking wells, the $586 million market for distributed fiber-optic lines will almost double in the next three years.
Image: preparing water tanks via Wikimedia
This post was originally published on Smartplanet.com