Geophysics - Reservoir Characterization

Seismic Reservoir Characterization

 

Instructor

  Dr Sagar Ronghe (DownUnder GeoSolutions, Perth, Australia)

Duration

  1 or 2 days

Disciplines

  Geophysics – Reservoir Characterization

Level

  Foundation

Language

  English

EurGeol

  5 or 10 CPD points

Keywords

 
 2D   3D   AMPLITUDE   DEPTH CONVERSION   IMPEDANCE   INTEGRATION   INTERPRETATION   INVERSION   LITHOLOGY   ROCK PHYSICS 

 

Course description

Well and seismic data can be integrated to predict lithology and fluid, quantify reservoir properties, identify leads and help risk prospects. This course provides an introduction to the concepts and application of quantitative seismic interpretation including statistical rock physics analysis and modeling.

This course discusses reservoir characterization as it applies to all stages of oil and gas field activity: from reconnaissance, through exploration and appraisal, to focused reservoir characterization during field development. As more data become available the options for QI increase. Workflows should be fit-for-purpose given project objectives and data availability. Reservoir characterization methodologies spanning qualitative attributes, inversion, probabilistic lithology and fluid predictions and the quantification of reservoir property distributions are presented. These include well log calibrated amplitude and AVA interpretations, stack rotations and deterministic and stochastic inversion. The importance of petrophysics and rock physics calibration as a foundation for all of these methods is highlighted.

The course also discusses seismic velocity modeling: the smooth merging of multiple 2D and or 3D velocity fields into a consistent 3D volume; and the calibration of seismic velocities to well data for accurate time-to-depth conversion. Depth conversion of seismic data and derived properties are important for facilitating well planning and field development decisions as well as for quantitative result interpretations.

 

Course objectives

Upon completion of the course, participants will gain fundamental knowledge of the concepts, applications and benefits of multiple reservoir characterization techniques. They will be introduced to the importance of petrophysics and rock physics in establishing well-to-seismic calibration and in providing the framework for results interpretation. Participants will obtain an understanding of the data conditioning requirements for quantitative interpretation work and an appreciation of how to review results for quality and consistency.

 

Course outline

Morning session

Introduction to seismic reservoir characterisation:

Overview and types; qualitative and quantitative; available workflow options and applications.

Statistical Rock Physics:

Importance of well data consistency and conditioning; petrophysics for quantitative interpretation; introduction to rock physics; wireline end-member picks and trends; stochastic forward modelling of trends to understand the population behaviour of the data and to assess depth dependencies; case study examples.

Amplitude and AVA:

Reflectivity and seismic concepts; secant amplitude interpretation for lithology and fluid distributions; AVA classifications and analysis; seismic conditioning for AVA work; case study examples.

Stack Rotations:

Concepts of weighted stacks and rotation angle curves towards determining lithology and/or fluid distributions; applicability to seismic data, AVA products and inversion derivatives; elastic and extended elastic impedance; case study examples.

Afternoon session

Deterministic Inversion:

Concepts, types and benefits; constrained absolute simultaneous inversion: workflow overview and results QC; probabilistic lithology and fluid predictions; implications of broadband seismic; case study examples.

Stochastic Inversion:

Concepts; workflow overview; results and case study examples.

Velocity Modelling:

Concept of smooth merging (levelling) velocities within a 2D survey or between 2D and/or 3D surveys; geostatistical velocity scaling for optimal time-depth conversion through calibration to well data; case study examples.

Summary of QI workflows:

Overview of applicability of reservoir characterisation techniques during reconnaissance (AVA attributes and calibrated stack rotations), exploration & appraisal (relative and/or absolute simultaneous inversion), and focussed field development (stochastic inversion).

 

Participants' profile

The course would benefit all technical staff in exploration and development who are interested in determining formation properties through seismic and log data integration.

 

Prerequisites

Participants should have basic knowledge of seismic data and well logs.

 

About the instructor

Dr Sagar Ronghe

Dr Sagar Ronghe specialises in Quantitative Interpretation integrating wireline and seismic data. He has over 20 years of experience in seismic reservoir characterisation. Sagar is a Geoscience Manager with DownUnder GeoSolutions, based in Perth, Australia. His educational qualifications comprise a Bachelors in Geological Oceanography from the University College of North Wales, UK, a Masters Distinction in Petroleum Geology and a PhD in Geophysics, both from the University of Aberdeen, UK. He began his career in 1996 as a Lecturer in Geophysics at the University Brunei Darussalam. In 2002, he joined Fugro Jason as a Project Geoscientist based in Kuala Lumpur, relocated to Perth in 2007 and was appointed Regional Technical Manager for Fugro Jason in 2012. Sagar has been with DownUnder GeoSolutions since 2013.

 

Recommended reading

  • Castagna, J.P., et.al., 1985. Relationships between compressional-wave and shear-wave velocities in clastic silicate rocks. Geophysics, 50:571-581.
  • Gardner, G.H.F, et.al., 1974. Formation velocity and density - the diagnostic basics for structural traps. Geophysics, 39:770-780.
  • Glinsky, M.E., et.al. 2005. Integration of uncertain subsurface information into multiple reservoir simulation models. The Leading Edge. October. 991-999.
  • Lamont, M. G., Thompson, T. A. and Bevilaqua C., 2008, Drilling success as a result of probabilistic lithology and fluid prediction — A case study in the Carnarvon Basin, WA, APPEA Journal, 2008.
  • Rutherford, S.R., and Williams, R.H. 1989. Amplitude-versus-offset variations in gas sands. Geophysics. v.54., no. 6., pp. 680-688.
  • Whitcombe, D., Connolly, P., Reagan, R., and Redshaw, T. (2002). Extended elastic impedance for fluid and lithology prediction. Geophysics, 67(1), 63-67.

 

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