While naturally-fractured reservoirs are an important component of the global hydrocarbon reserve and production base, they are notoriously difficult to image. To map fracture patterns and associated reservoir permeability changes within these heterogeneous reservoirs, and to target highly productive zones during drilling operations, geoscientists must be able to acquire wide azimuth, high fidelity, broadband seismic data, as well as to process it in different ways.
A key part of fractured reservoir characterization is being able to take high-quality measurements of anisotropy, which indirectly indicates fracture orientation and intensity. In a vertically-fractured zone, AVO response will vary with azimuth. The largest variation will occur between AVO responses parallel and perpendicular to the dominant fracturing direction.
In order to measure anisotropy and properly characterize fractured reservoirs, geophysicists must apply innovative imaging approaches in order to:
- Design surveys customized for fractured reservoir imaging, where long offsets, wide azimuth geometries and high sensor densities are often needed to detect and resolve fracture patterns and connectivity
- Measure seismic response with high fidelity and accuracy using VectorSeis full-wave sensors, especially to assess attributes unique to fractured reservoirs such as fast and slow interval velocities, azimuthally-varying velocities and AVO, and shear wave splitting intensity and orientation
- Improve image quality and resolution by accounting for azimuthal velocity variations with AZIM, ION’s suite of anisotropic velocity imaging applications
- Use seismically-derived fractured reservoir parameters and subsurface information to calibrate and generate discrete fracture network reservoir models that guide drilling decisions and field development planning
As a proven leader in developing cutting-edge acquisition hardware and software, as well as in offering services for seismic survey design and advanced imaging, ION is becoming a clear first-choice provider for E&P operators whose asset portfolios include fractured reservoirs.
