Unconventional Reservoir Geomechanics

The production of hydrocarbons from extremely low permeability unconventional reservoirs through horizontal drilling and multi-stage hydraulic fracturing has transformed the global energy landscape. Although hundreds of thousands of wells have been drilled and completed, recovery factors remain low in both tight oil (2-10%) and shale gas (15-25%) reservoirs. This course, designed for both geoscientists and engineers, covers topics ranging from the physical properties of reservoir rocks at the nanometer- to centimeter-scale to the state of stress on fractures and faults at the basin-scale. The course follows the textbook Unconventional Reservoir Geomechanics by Mark Zoback and Arjun Kohli, available in print or electronic versions.

Unconventional Reservoir Geomechanics, Cambridge University Press 2019

https://www.cambridge.org/core/books/unconventional-reservoir-geomechanics/39665444034A2EF143D749DF48A5E5DC

The first part of the course covers topics that become progressively broader in scale, starting with laboratory studies of the microstructural, mechanical, and flow properties of reservoir rocks and concluding with field observations of fractures, faults, and the state of stress in unconventional basins. The second part of the course focuses on the process of stimulating production using horizontal drilling and multi-stage hydraulic fracturing. Important engineering concepts will be reviewed, including microseismic monitoring, production and depletion, well-to-well interactions, and hydraulic fracture propagation. The final part of the course addresses the environmental impacts of unconventional oil and gas development, in particular the occurrence and management of induced seismicity.

Two units will be released each week on edX. Each unit will be comprised of 3-5 video modules 10-20 minutes in length. Videos can be accessed at any time before the end of the course. Grading will be based entirely on 6 homework assignments. Homeworks are due on edX at the start of each week at 07:00 UTC (00:00 PST). Students who select the verified enrollment option and earn at least 70% on the homeworks will receive a certificate from edX.

Syllabus

4/6 Week 1

Unit 1: Introduction and Course Overview

Unit 2: Unconventional Reservoirs

4/13 Week 2

Homework 1 – State of Stress in Unconventional Reservoirs ****

Unit 3: Stress, Fractures and Faults I

Unit 4: Horizontal Drilling and Hydraulic Fracturing

4/20 Week 3

Homework 1 Due

Homework 2 – Composition and Elastic Properties

Unit 5: Composition, Fabric, Elastic Properties and Anisotropy

Unit 6: Rock Strength and Ductility

4/27 Week 4

Homework 2 Due

Homework 3 – Ductility, Friction, and Stress Magnitudes ****

Unit 7: Ductility and Stress Magnitudes

Unit 8: Frictional Properties

5/4 Week 5

Homework 3 Due

Homework 4 – Flow and Sorption

Unit 9: Pore Networks and Pore Fluids

Unit 10: Flow and Sorption ****

5/11 Week 6

Homework 4 Due

Homework 5 – Stress, Faults, and Reservoir Seismology ****

Unit 11: Stress, Fractures, and Faults II

Unit 12: Reservoir Seismology

5/18 Week 7

Homework 5 Due

Homework 6 – Induced Shear Slip on Faults

Unit 13: Shear Stimulation and Depletion

Unit 14: Stimulation Optimization

5/25 Week 8

Homework 6 Due

Unit 15: Production and Depletion

Unit 16: Environmental Impacts

6/1 Week 9

Unit 17: Induced Seismic and Unconventional Reservoir Development

Unit 18: Managing Risk of Induced Seismicity

6/8 Week 10

Unit 19: Discussion and Wrap-up