Education

CSEG DoodleTrain

Fractured and Shale Reservoirs: From Geologic Concepts to Reservoir Models

Instructor: Ahmed Ouenes / John Lorenz
Date: November 4 - 5, 2010
Duration: 2 days
Members (early bird/price): $700/$900 CDN (plus GST)
Non-Members (early bird/price): $800/$1000 CDN (plus GST)

Venue: GX Technology (ION), Altius Building Classroom – Altius Centre, 500 - 4th Ave SW, 2nd Floor, +15 Level
Time: 8:00am - 5:00pm

Audience:

Geologists, Geophysicists, Reservoir Engineers and Geomodellers

Course Description:

The short course provides a unique opportunity to learn all the aspects related to the understanding and modeling of fractured reservoirs. The workshop includes both presentations and hands-on training using a software (ReFract). The first part of the workshop covers the geologic aspects which allow the geoscientist to recognize different types of fractures from outcrop, cores and boreholes. Once the fractures are recognized, their impact on the reservoir and its performance is examined. Six case studies are used to illustrate all the geologic concepts. The second part of the workshop covers all the aspects of modeling fractured reservoirs. Using ReFract and actual data from Teapot Dome, (WY) Niobrara shale, the geoscientist will be able to construct fracture models that integrate geology, geophysics and reservoir engineering. Emphasis will be given to the critical use of high resolution seismic attributes derived from inversion, volumetric curvature and spectral imaging. Using actual Teapot Dome field data from the Niobrara Shale formations and a hands-on approach, the workshop allows the geoscientist to identify fractures and to construct 3D fracture models that can be used to identify productive zones and areas, plan wells and to create fracture porosity and permeability models for reservoir simulation. The students can take the concepts learned in this class and use them to solve his own problems. Many commercial and open source software (Petrel, OpendTect, EMERGE from Hampson Russel, Geomodeling, etc..) offer tools similar to those used in ReFract during the course.

Format:
The course will consist of taught lectures and practical sessions. Real field examples will be taught using ReFract software and Niobrara shale Teapot Dome data.

Contents:

Part 1: Geologic Aspects of Fractured Reservoirs

A. Introduction: Fracture Types and Variability

  1. extension fractures
  2. shear fractures
  3. deformation bands
  4. fractography
  5. mineralization
  6. fracture swarms and corridors
  7. microfractures
  8. compound fractures
  9. faults

B. Fractures in Core: Natural Fractures

  1. extrapolating from the surface to the subsurface
  2. distinguishing natural from induced fractures in core
  3. fracture types in core
  4. collecting fracture data from core
  5. quality checking an orientation survey
  6. measuring fracture orientations in core
  7. image logs

C. Fractures in Core: Induced Fractures, Types and Uses

  1. petal fractures
    • saddle fractures in horizontal core
    • using petal fractures
  2. Other induced fractures and artifacts

D. Fracture Mechanics

  1. contraction fractures
  2. lithologic mis-matches and bedding-plane tractions
  3. extension fractures in flat-lying strata
    • the important effects of pore pressure
  4. shear fractures: conjugate shears, en echelon veins, and deformation bands
  5. dynamically compatible fractures
  6. fractures in limestone vs. fractures in sandstone

E. Fractures on Anticlines

  1. Stearns and Friedman vs. Cooper models/Teapot Dome
  2. Salt Valley: stretching features over a mobile salt core
  3. drapes over dissolution fronts
  4. Wyoming anticlines – UW Enhanced Oil Recovery Institute Tensleep Fm studies

F. Fracture Spacings

  1. spacing variability
  2. sampling problems
  3. measuring spacing
  4. geometry and wellbore efficiency

G. Fracture Effects on Reservoirs

  1. permeability enhancement and anisotropy
  2. permeability baffles and barriers
  3. dynamic permeability
  4. corridors and sweet spots
  5. interactions between stimulation fractures and natural fractures
  6. nuclear stimulations

H. Case Histories

  1. Spraberry Formation: Permian Basin, Texas
  2. Frontier Formation: Green River Basin, Wyoming
  3. Mesaverde Formation: Piceance Basin, Colorado
  4. Fractures in lenticular sandstones: Uinta Basin, Utah
  5. Mesaverde Formation: San Juan Basin, New Mexico
  6. Raton Basin, Colorado-New Mexico

Part 2: Modeling Fractured Reservoirs

A. Introduction

  1. Classification of fractured reservoirs
  2. Classification of fractures

B. Factors Affecting Fracturing
The notion of fracture drivers is introduced with a focus on the influence of the following drivers on reservoir fracturing:

  1. structure
  2. distance to fault and fault throw
  3. porosity
  4. lithology
  5. reservoir thickness

C. Methodologies to Characterize Fractured Reservoirs

  1. Continuum Fracture Modeling (CFM)
  2. Discrete Fracture Modeling (DFN)
  3. Geomechanical aspects of fracture modeling.

D. The Use of Seismic to Improve the Fracture Modeling

  1. The use of high-resolution seismic inversion
  2. Spectral imaging and volumetric curvature
  3. Pre-stack seismic and azimuthal analysis

E. Integrated Workflow Applied to Fractured Reservoirs
Case studies: application of the CFM methodology on several fractured reservoirs around the world to determine:

  1. the matrix block size
  2. the fracture intensity distribution
  3. the fracture permeability distribution
  4. the fracture porosity distribution

F. Hands-on Application: Dataset from the Teapot Dome (WY)

  1. Teapot Dome Niobrara shale formation

Presenter / Instructor Biography:

John C. Lorenz
I earned my undergraduate degree, majoring in geology and anthropology, from Oberlin College in 1972, after which my wife dragged me off to Morocco to teach English and learn Arabic with the Peace Corps. In Morocco, I ran into a group of geologists from the University of South Carolina, and hooked up with them to do an M.Sc. on a Moroccan Triassic rift basin. I worked for the USGS in Louisiana and New Mexico from 1975 to 1977, which drove me back to school, where I worked on the Nubian Sandstone in Libya and Cretaceous strata in Montana and earned a PhD from Princeton University in 1981. I joined Sandia National Laboratories in 1981 to be the geologist for the tight gas Multiwell Experiment in the Piceance basin, where I invented the internet and discovered natural fractures. I worked for Sandia Labs from 1981 to 2007, doing fractured-reservoir studies in exotic places such as Alaska, Algeria, and Texas. During that time, I was conned into being the AAPG Elected Editor from 2001-2004. I am the 2009-2010 president of the American Association of Petroleum Geologists from 7/1/09 to 6/30/10. As president, I support the advancement of the geosciences and their applications to hydrocarbon-related problems. I left Sandia in March of 2007 and have been busy with AAPG and as a consultant ever since.

My published papers on natural and induced fractures in reservoirs range geographically from the Lisburne Limestone in Alaska to the Spraberry Formation in Texas. These papers and presentations have been awarded the AAPG Levorsen and Jules Braunstein awards. I have worked closely with the oil and gas industry on problems involving reservoir dimensions and in situ permeability, gaining extensive hands-on experience with core analysis and fieldwork, which provides regular doses of reality. I have led field trips, presented core workshops, and taught short courses for the industry-oriented geological community. My work has been practical, aimed at improving the understanding of fractured reservoirs and permeability in order to enhance fluid extraction. I have also addressed the problems of determining the dimensions of reservoirs deposited in fluvial environments, and ferried new-purchase aircraft across the US in both directions.

Ahmed Ouenes
Ahmed Ouenes is the president of Prism Seismic. Ahmed graduated from Ecole Centrale de Paris and joined Elf-Aquitaine to conduct research on wettability in New Mexico, USA. After getting his Ph.D. in Petroleum Engineering, he joined the New Mexico Petroleum Recovery Research Center where he focused on the development of new reservoir characterization techniques. Among these new techniques he developed the Continuum Fracture Modeling (CFM) technology which has been successfully applied throughout the world. The CFM technology is the only available technology that is able to successfully integrate seismic, geologic and geomechanical information. Ahmed joined (RC)2 where he was the Chief Reservoir Engineer and the developer of the first commercial software for the CFM technology. After the acquisition of (RC)2 by Veritas, Ahmed shifted his focus to the development of new advanced seismic technologies that can be used in reservoir characterization in general and fracture modeling in particular. Ahmed published more than 50 papers and was an SPE editor.


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