« Back to course list

Geomechanics at Well and Field Scale (GEO75)

    Description

    Various subsurface project risks can be reduced significantly by proper geomechanical understanding and associated pressure – and sometimes also temperature – management during operations. Non-productive drilling time is regularly attributed to bore hole instability and associated stuck-pipe incidents, sand failure and sand production may cause erosion of equipment and filling-up of separation facilities, while unintended and uncontrolled fracturing may create permeable pathways and loss of containment of reservoir fluids. Field-scale geomechanical assessments also provide important input to safe operating envelopes for the reservoir pressure as well as production & injection wells. Reservoir compaction (and pore collapse) may cause a reduction of reservoir permeability, mechanical well failure and unacceptable (seabed) subsidence. Fault reactivation may create permeable pathways and loss of containments (e.g., in waterflood operations and Carbon Capture Storage projects) and even induced seismicity. Proper geomechanical understanding of the subsurface response to our operations is essential, both at well scale and on field scale.
    This course covers data acquisition and interpretation, geomechanical modelling, and interpretation focussed on managing the aforementioned project risks. Data acquisition includes field data, such as (X)LOT, and petrophysical log data to estimate formation properties using correlation functions. Also, attention is paid to rock mechanical experiments and interpretation. Geomechanical modelling is applied at material point level (poro-elasticity theory, shear & tensile failure, plastic & viscous modelling), at wellbore scale (stress around the bore hole) and at field-scale using Finite-element modelling techniques.


    Course Level: Skill / Advanced
    Duration: 5 days
    Instructor: Peter van den Bogert & Alice Post

    Designed for you, if you are...

    • Involved in field development and responsible for or doing hands-on geomechanical hazard and risk assessments. This could be well engineers, production staff, geologists, reservoir engineers and petrophysicists. Subsurface team leads, or staff/managers that oversee externally conducted geomechanical studies should also join to challenge results and provide technical & risk assurance to their development projects.
    • Practical MS Excel skills are desired for optimal learning benefits.

    How we build your confidence

    • This course provides several quizzes which are done individually, and exercises that are done either in small groups or individually, as appropriate.
    • Exercises will involve some calculations for which calculators or simple MS Excel spreadsheets are used.
    • The course provides a venue for discussion, raising questions and sharing of experience.
    • Participants are encouraged to bring their own work issues and challenges and seek advice from the expert course leader and other participants.

    The benefits from attending

    By the end of the course participants will be able to:
    • Identify potential project risks that may need a geomechanical evaluation, and develop a work plan to assess them
    • Construct a pressure-depth plot with the in-situ stress & pore pressure condition based on available field data
    • Construct and interpret a Mohr-circle for shear and tensile failure
    • Employ log-based correlation function to estimate mechanical properties
    • Identify potential lab experiments to measure required formation properties
    • Calculate the mud weight that leads to shear and tensile failure (fracturing conditions)
    • Understand the impact of well orientation on the recommended mud weight / bore hole instability
    • Describe the workflow and data to develop a field-wide fit-for-purpose geomechanical model
    • Estimate reservoir compaction and (seabed) subsidence using simplified analytical approaches
    • Produce a simplified, but appropriate geometrical (layered, upscaled) model that honours contrasts in initial stress, formation properties and loading conditions, including
    • Outline the qualitative impact of pressure and temperature change on the risk related to compaction, well failure, top-seal integrity and fault reactivation

    Topics

    Risks & Initial Stress
    • Introduction, course overview, objectives
    • Overview of project risks
    • Geomechanics at well & field scale
    • Workflow, data requirements
    • Stress in the Earth, vertical stress
    • Minimum principal stress, (X)LOT, etc.
    • Intermediate principal stress & Geology
    • Pore pressure - Basic concepts
    • Properties from experiments

    Fundamentals
    • Pore pressure
    • Over pressure causes
    • Pore pressure measurement
    • Pressure-Depth plot
    • Equilibrium, (principal) stress & strain
    • Mohr circle
    • Linear elasticity in 1D, 2D & 3D
    • Properties from experiments
    • Material failure, Mohr-Coulomb

    Bore Hole Stability
    • Poro-elasticity & thermo-elasticity
    • Stuck-pipe prevention
    • BHS, differential sticking and hole cleaning
    • Stress distribution around the bore hole
    • The role of mud weight, examples
    • Polar plots: impact of dip angle and azimuth
    • Oil-based vs. water-based muds
    • Bore hole failure: instability, lost circulation
    • Over-pressure & in-fill drilling

    BHS & Field-Scale Modelling
    • BHS workflow
    • Offset & other well data
    • Formation properties from logs
    • Determining the optimum mud weight
    • Field scale geomechanics
    • Modelling & interpretation
    • Reservoir depletion, change of in-situ stress
    • Well trajectory planning, in-fill drilling
    • Reservoir pressure reflation

    Well Failure: Compaction, Fault Reactivation & BHS
    • Well failure due to reservoir compaction
    • Well failure due to slip layers
    • Stress on a fault plane
    • Fault reactivation & a-seismic slip
    • Reservoir offset: when not to use a Mohr-circle analysis and 3D models
    • Fault reactivation & bore hole stability
    • How to screen for geomechanical risks
    • Developing the work plan






    Customer Feedback

    "Substantial material with lot of fundamental background.” - Wellsite Geologist at ETAP

    “I learned so much about Geomechanics and how to integrate it with Petrophysics especially. So I am extremely satisfied!” - Petrophysicist at ETAP


      Enquiry

      Name:
      E-Mail:
      Company:
      Message:
      Newsletter:

      © All rights reserved
      HOT Engineering GmbH   Tel: +43 3842 43 0 53-0   Fax +43 3842 43 0 53-1   hot@hoteng.com