Integrated Interpretation

Operators are interested in maximizing value from their data streams. Geophone microseismic data can be integrated with various other data streams such as fiber optic distributed acoustic sensing (DAS), slow strain, distributed temperature sensing (DTS) and tiltmeter measurements for more complete understanding and optimization of hydraulic fracturing operations.

Fiber Optic DAS Strain

Distributed fiber optic technology consists of a fiber cable with an intrinsic sensor that measures the spatial distribution of acoustic vibrations (DAS) along the sensing  fiber. The  low-frequency (<0.05 Hz) component of DAS (LF-DAS) is a powerful tool to monitor small strain perturbations caused by hydraulic fracturing.

The completion effectiveness of a hydraulically fractured well can be monitored with fiber installed in the treatment well (in-well monitoring) or with fiber installed in offset wells (cross-well monitoring). In-well fiber monitoring is used to understand the perf cluster efficiency, fluid allocation, and cross-stage  fluid  communications. Offset-well  fiber can  be  used  to  detect fracture-driven interactions, also called frac-hits. 

ESG and OptaSense have teamed up to deliver unconventional operators with a new, retrievable wireline system for simultaneous fiber-optic DAS and 3-component geophone microseismic acquisition.

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Distributed Temperature Sensing (DTS)

Distributed Temperature Sensing (DTS) uses fiber optic sensor cables that function as linear temperature sensors. The result is a continuous temperature profile along the entire length of the sensor cable.

Near-well DTS applications include: 

  • Isolation effectiveness (between perforation clusters)
  • Relative amount of fluid each perforation cluster takes
  • Fracture initiation points
  • Effective fluid diversion

Distributed sensing systems have been developed for the oil and gas industry to assist reservoir engineers in optimising the well lifetime. 

Distributed fiber optic monitoring offers high spatial and temporal profiling over large surfaces, long lengths and at locations where conventional point-sensing is not applicable or cost effective.

Tiltmeter Measurements

We are leaders in microseismic frac mapping and induced seismicity monitoring. We’ve recently developed a mapping technology that combines the benefits of downhole microseismic with a direct measurement of fracture geometry that is insensitive to rock type or velocity models.

Ultra-small MEMS tiltmeters have been incorporated into our downhole HOTSHOTTM microseismic tools. Tiltmeters are sensitive geophysical sensors that measure the slow, aseismic physical deformation of the reservoir during fracture treatments.

Fracture heights can be interpreted with increased confidence with a combination of tiltmeter and 3-C geophone sensors within the same toolstring. HOTSHOTTM equipment and wireline are high temperature rated to 350F and can be deployed for extended periods of time.

Unlike other hydraulic fracture mapping techniques, tiltmeters and optical fiber are sensitive to rock mechanical and fracture geometrical properties. Tiltmeters provide quantitative fracture heights for each stage near the monitor well, and offer an opportunity to verify microseismic results, as they enable a direct comparison between strain and seismic fields.