Oil and Gas
E & P professionals completing this course will understand the theory and the practical application of multi-azimuth PP 3D surface seismic and well-bore technologies including microseismic monitoring. Participants will acquire the skills required to actively participate in the planning of data acquisition and processing of azimuthally dependent 3D seismic surveys and VSPs and also the interpretation skills required to analyze data from azimuthally anisotropic unconventional reservoirs. A discussion of the use of multi-component 3D is offered, if participants have multi-component data back in their office.
Duration and Training Method
Participants will learn to:
- Understand the fundamentals of seismic wave propagation in anisotropic media and the relevance of wide azimuth multi-component and PP seismic technologies in the evaluation of unconventional reservoirs.
- Recognize the importance of symmetry in the subsurface and how it might impact seismic wave propagation and data interpretation.
- Utilize data sources such as outcrop information, core analyses, cross dipole sonic logs, VSPs, passive (micro-seismic) monitoring, and other down-hole tools to calibrate seismic responses from fractured reservoirs.
- Provide direction in the planning of 3D seismic and VSP surveys to achieve exploration objectives.
- Supervise seismic data processing activities to preserve azimuthally- dependent parameters such as travel times, frequency, phase, and AVO.
- Assess the relevance of various seismic attributes from azimuth sectored pre-stack time migrated 3D data.
- Construct workflows using multi-attribute seismic data to characterize unconventional reservoirs.
- Provide direction in the planning of drilling programs.
- Overview: Why anisotropy is a useful tool for unconventional reservoirs
- Fundamentals of P and S wave propagation: Isotropy, layer and azimuthal anisotropy, homogeneity, heterogeneity, unequal horizontal stress, the Thomsen parameters
- Symmetries of sedimentary rocks: VTI (flat layers), HTI (unequal horizontal stresses and/or 1 set of vertical aligned fractures), ortho-rhombic (flat layers + vertical cracks and/or the tri-axial stress field having one stress truly vertical), monoclinic, triclinic
- Multi-component terminology, shear wave splitting
- Robust seismic measurements of anisotropic parameters
- Introduction to passive seismic (micro-seismic) monitoring
- Acquisition considerations: full azimuth/full offset 3D surveys; P-P, P-S, vertical component and 3C receivers
- 3D wide azimuth data processing: P-P goals, issues, techniques.
- Offset Vector Tile binning to optimize PSTM results
- Sectored azimuthal traveltime analysis vs. non-sectored approach
- Pre/post stack inversion: Azimuthal P and S impedance
- Support data: Multi-azimuth VSPs, crossed dipole sonic, FMI/FMS, borehole televiewer, World Stress Map, outcrops, oriented cores, local structure maps, production data, interference data, multi-well testing
- Case History: Micro-seismic monitoring (surface and down hole) combined with surface seismic measurements
- Rock physics
- Lab measurements of VP and VS in non-fractured rock
- Rock properties that affect VP/VS
- Geomechanical properties that affect P and S wavefields
- Lab measurements of S velocity behavior in fractured rock
- Determining fast-S and slow-S azimuths with 3C data
- P-wave propagation in fractured rock
- Stress and fracture concepts
- Interpretation techniques (P-P): Azimuthal analyses of travel times and AVO
- Hydro-fracture considerations, inherent reservoir strength (mineralogy, composition, porosity, cementation), in-situ horizontal stress field, paleo-strain features (existing faults and fractures).
- Exercise: Modeling of P-P and P-S amplitude responses
- Overview of mapping software for interpretation purposes
- Overview of microseismic monitoring
-Fundamentals and data collection
Who Should Attend and Prerequisites
This course has been designed for geoscientists familiar with the basic principles involved in seismic reflection and VSP technologies and who have an interest in the exploration and/or development of unconventional reservoirs. Prospective students should also have a minimum of one-year’s experience interpreting 3D seismic data before attending this class.
Dr. Heloise Lynn specializes in the use of multi-azimuth and/or multi-component data (P-P, P-S, S-S) collected over anisotropic sedimentary rocks for reservoir characterization and exploration. She specializes in the use of seismic anisotropy recorded in full-azimuth full-offset 3D seismic reflection field data to obtain structure, lithology, porosity, pore fluid, unequal horizontal stresses, and/or vertical aligned fractures that flow fluids. She focuses on methods to distinguish between in situ horizontal stress effects versus vertical aligned fractures that flow fluids. Lynn Incorporated also provides training and technology transfer. In order to obtain successful results on field studies, she provides: seismic acquisition design and recommendations; pre-acquisition modeling; monitoring and quality checking during onshore and offshore acquisition; specify the processing flow; supervise and quality check the processing; and interpret data using all available geologic data, for full-azimuth and multi-component seismic projects; co-render azimuthal measurements using “icons” which hold 3 numbers in each colored glyph, with 3 or 4 icons displayed on the structure map. She also concentrates on the modeling of field data results, to support interpretation. She assists clients to round up their required support datasets for a multi-azimuth/multi-component projects. Her further interests also include: re-processing and using VSP multi-component data in conjunction with 3D multi-azimuth multi-component surveys, and passive seismic monitoring during hydro-frac. She is also interested in fractured basement reservoir plays: how to use full-azimuth 3D seismic reflection to efficiently develop these reservoirs, even when the reservoir is in the “non-layered” basement rocks.
During the last twenty-five years, she has personally worked over twenty-five 3D PP wide-azimuth field data surveys and/or 3D multicomponent surveys acquired, processed, and interpreted for seismic anisotropy, in order to learn fracture azimuth, fracture density, and in-situ stress state, as the lead geophysicist assigned to the project. During the last thirty years, she has published more than 40 technical articles in Geophysics or The Leading Edge, documenting the uses of seismic anisotropy as recorded in seismic reflection field data.
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