
Optimize impact of distributed fiber optic sensing data for hydraulic fracturing, reservoir, and geotechnical applications
Distributed fiber optic sensing (DFOS), including distributed acoustic sensing (DAS), provides valuable strain and temperature data that helps quantify fracture properties, fluid flow, and subsurface rock deformation. These insights are critical for a broad range of applications in unconventional and conventional reservoir analysis, geothermal field development, and many geotechnical problems. The SeisPetro team will provide expert guidance in applying results to maximize the value of the complex fiber datasets.
Low frequency strain
One important measurement from DAS monitoring of subsurface process is the slow variation in the strain, or mechanical deformation, measured by the fiber optic cable. This result provides an estimate of quasi-static, gradual deformation of a rock medium created by newly forming hydraulic fracture systems. Computation of this slowly varying quantity also provides a dramatic reduction in the data volumes that were originally required with 1000s of samples per second. SeisPetro can provide expert guidance in interpreting the results and relating them to simple fracture models with arbitrary geometry and width (aperture). We can also reprocess the original data to extract the low frequency results.
Integration of low frequency and microseismic data
Each type of measurement provides important insights to better understand newly formed hydraulic fracture systems, but combining both into a single model provides richer and more complete models of the stimulated reservoir volume. SeisPetro will provide quantitative fracture models consistent with both low frequency and microseismic results. This provides a hydraulic fracture model that is consistent with both data types, and improved estimate of the effective volume contributing to production.
Microseismic events
The formation of new, large tensile fractures during hydraulic fracturing strains nearby, naturally occurring fractures, and this leads to sudden motion on these pre-existing fractures surfaces. Waves generated by these microseismic events - tiny earthquakes - are detected by DAS systems. Production of fluids from subsurface reservoirs, or injection of fluids into them, also can generate microseismic activity. For hydraulic fracturing, the data provides constraints on the newly formed fracture flow systems, while for production and injection the measurements can quantify changes in stress systems and potential risks associated with larger earthquakes. We provide guidance in interpreting event catalogues generated from DAS and/or geophone data. SeisPetro will also apply expertise in geomechanics, petrophysics and fracture modeling to integrate the microseismic data with other data such as seismic reflection imaging, well logs, and outcrop analogues.
General applications of distributed fiber optic sensing
DAS and distributed temperature sensing (DTS) are finding increasingly important usage in tasks such as monitoring dam integrity, land slides, reservoir fluid flow, and well casing integrity. SeisPetrol offers consulting services in design and implementation of DFOS for many of these applications.
