Saturation-Height Modelling for Reservoir Description

Everything you need to know about Saturation-Height - The Course based on the Book.

Water saturations (Sw) in conventional oil & gas reservoirs are controlled by capillary pressures. Wireline logs can approximate what Sw may be, but do not actually measure Sw directly. Hence, when it comes to building reservoir models and estimating volumes in-place, capillary pressure based saturation-height models are used to de- scribe Sw.


For unconventional reservoirs, even if capillary pressures are not controlling Sw, saturation-height modelling provides a means to describe Sw variations in reservoirs using property variations.


Note too that CO2 “saturations” in underground Carbon Capture and Sequestration projects are also initially controlled by capillary pressures, enabling likely storage volumes to be estimated using saturation- height modelling techniques.


Course Objectives

The course provides best practice guidelines to create meaningful saturation-height functions from capillary pressure measurements and log interpreted Sw. Both drainage and imbibition modelling and the reasons for discrepancies between saturation-height and log- derived water saturations. Will be covered. Implementation of appro- priate models in log interpretation, static and dynamic modelling, unconventionals and carbon capture will be addressed.


Emphasis will be placed on methodologies which can be satisfactorily audited by external technical experts and joint venture partners.


Who Should Attend?

Geologists, Geophysicists, Reservoir & Production Engineers and others involved in formation evaluation and/or reservoir modelling. In particular, people who work with hydrocarbon saturations in their models will find this course of considerable benefit


What Skills Will Participants Gain?

Participants will gain a greater understanding of the processes controlling hydrocarbon distribution in reservoir rocks. The reasons for varying oil-water or gas-water contacts in reservoirs with the same Free Water Levels are just one example of the insights provided by an understanding of capillary pressures.


This course will also provide a step-by-step guide to deciding which capillary pressure measurements to acquire and how to interpret those measurements to yield formulae for use in estimating water saturations independently from wireline log derived water saturations.

Having these formulae for reservoir description provides the foundation for additional investigations that can be carried out using the combination of saturation-height functions, log evaluations, formation pressures and geological configuration. Suitable investigations will be detailed in the latter part of this course, and provide a significant opportunity for participants to improve their understanding of their own Fields and how their hydrocarbon systems may actually be working.


Duration

The course is most often supplied as an intensive two day program, although it can also be delivered as a more relaxed 3 day course. Numbers are usually limited to less than 20 people making it possible for the Course Trainer to ensure all participants are following the curriculum.


Course Materials

A detailed training manual is provided to facilitate learning and use of the material - in this case it includes the 2016 Book. The course will alternate between lecturing with Powerpoint Slides and exercises with data from real oil and gas Fields. The exercises are intended to reinforce the ideas and methodologies discussed. MS-Excel will be used for the exercises rather than dedicated Petrophysics software so that the participants understand which algorithms they should use and why. 


Course Content

As with all our courses, this course is fully customisable to suit client requirements.


An outline of the Saturation-Height Modelling for Reservoir Description training course follows (more details can be found in the table of contents of the Book):


  • Capillary Pressure - The Basic Forces (Surface Tension & Wettability), In the Reservoir, Fluid Contacts, Nomenclature, Basic Formulae, Relative Permeability. Unconventionals & CO2 Storage.
  • Experimental Measurement - Sample preparation, Capillary Pressure Experiments (Mercury-Air, Porous Plate, Centrifuge, Steady-State, Vapour Desorption, NMR Analysis, Digital Rock Analysis), Wettability
  • Saturation-Height Study Planning - Results Orientated, Project Timing, Documentation & Audit Trails
  • Experiment Selection - Low Permeability Reservoirs, Medium to High Permeability Reservoirs in Primary Drainage, Medium to High Permeability Reservoirs in Primary Imbibition
  • Representative Data - Have Samples Been Representatively Selected, Correcting for Unrepresentative Sampling, Determining Weighting Factors
  • Data Collation & Formatting
  • Corrections Required - Closure or Conformance, Clay-Bound Water, Stress, Impact of Corrections
  • Baseline Conditions - Converting Fluid Systems, Pressure to Height Conversion, Combined Fluid and Pressure to Height Conversion
  • Quality Control - Comparing Different Measurement Types , Quality Control of Baseline Dataset
  • Irreducible Water Saturation - Water Saturation vs Porosity or Permeability, Uncertainty Quantification
  • Selection of Saturation-Height Models - Leverett-J, Brooks-Corey, Lambda, Thomeer, Skjaeveland, Machine Learning & Neural Networks, Interpolation
  • Saturation-Height Function Creation - Model Fitting, Individual Curve Correlation Method, All Curves Simultaneously Method, Problems with Parameter Selection, Recommended Initial Parameters for the Solver, Sub-Groupings, Uncertainty Quantification. Unconventionals & CO2 Storage.
  • Quality Control of Functions - Checking for “Good Behaviour”
  • Reconciliation with Log Data - The Importance of Permeability, Reconciliation with Log Evaluation, What is an Acceptable Match, Example Matches & Comments, Saturation-Height Functions from Logs
  • Imbibition Modelling - Column Previously at Irreducible Water Saturation , Column Previously in Transition Zone and/or Irreducible Water Saturation, Examples of Imbibition Modelling
  • Special Situations - Perched Contacts, Dual (or More) Porosity Systems, Oil or Mixed-Wet Systems, Gas-Oil-Water Systems
  • Implementation in Reservoir Modelling - Practical Implementation, The Effect of Scale on Saturation-Height, Porosity-to-Permeability Transforms, Water Saturation Averaging, Implementation in Petrophysical Modelling, in Static Models and in Dynamic Models
  • Additional Uses - Identifying Reservoir & Seals, Current and Original Free Water Level Location, Thin Beds & Dodgy or Missing Resistivity Logs, Pore Throat Size Distributions, Permeability Prediction


Location

Available as an in-house course organised for Operators and also as an Open Course at various locations around the world. If you are interested in an Open Course spot, contact us and we will let you know when there is sufficient interest for a course in your area.


Costs

Course costs vary depending on location, duration and numbers, but typically range from US$1600-3000 per person.