Oil and Gas
Business Impact: Participants on this course will learn to understand and evaluate the results of special core analysis (SCAL), and apply this to static and dynamic reservoir modelling.
The most widely used SCAL measurements made in commercial core analysis laboratories will be covered.
Duration and Training Method
This is a five-day classroom course comprising lectures, discussion, case studies, and practical exercises. Real data will be used wherever possible. All exercises can be completed using calculators and graphs or in Excel.
- Understand the purpose of electrical parameters, capillary pressure curves and relative permeabilities.
- Quality control the different measurements and assess how representative they are.
- Propose saturation parameters for input to a petrophysical model (including low and high-side realisations).
- Define excess conductivity and using appropriate measurements, incorporate it into a shaly-sand interpretation; Assess whether a shaly-sand equation is necessary.
- Understand what controls the shape of a capillary pressure curve and model individual curves with a curve fit.
- Use a set of capillary pressure curves to build a saturation-height function.
- Understand the concept of Wettability and how SCAL measurements relate to it.
- Understand the concepts of Relative and Effective permeability.
- Understand the difference and advantages/disadvantages of steady and unsteady state relative permeability measurements; Fit curves to raw data using Corey exponents.
- Integrate saturation-height functions with relative permeability curves to predict water cut in the transition zone.
Cores and Coring
- Coring equipment
- Biography of a core: from reservoir to laboratory
- Comparing logs and cores
- Preparation for measurements: plugging, cleaning and drying
Special Core Analysis
- What is SCAL?
- Sample selection
- Designing a program: constraints
Description of the Measurements
- Electrical properties (a, m, and n)
- Excess conductivity
- Capillary pressure
- Relative permeability
- Others: NMR, residual gas saturation, compressibility
Day 2: Electrical Measurements
- The Archie Equation
- Pickett plots and the Cementation Exponent (m)
- Saturation Exponent (n)
- Selecting m, n values for the model
- Variable m models
- Uncertainty analysis
- Definition and consequences
- Hill and Millburn’s experiments
- Cation Exchange Capacity and its relation to excess conductivity
- Co-Cw measurement
- 3 ‘Wet Chemistry’ methods
- Waxman-Smits Method
- When should a shaly-sand method be used?
- Other shaly-sand equations
- Health warning!
Day 3: Capillary Pressure and Saturation-Height Modelling
- Fluid distribution in porous rocks
- The saturation-height function (SHF)
- Applications of the SHF
- Derivation of the SHF
- Capillary rise
- Capillary pressure
- Capillary effects in real rocks
- Interfacial tension (IFT)
- Wettability and contact angle
- Oil wetness
- Buoyancy vs. capillary forces
Capillary Pressure Curves
- Porous plate
- MICP and pore size distribution
- Qualitative information from Pc curves
Developing a Saturation Height Function
- Data Collation and QC
- Selecting a function
- Curve fitting
- Accounting for changes in rock and fluid properties
- Comparison to log analysis and other data
- Imbibition and residual oil
Days 4 & 5: Review
- Contact angle (re-visited)
- USBM method
- Amott method
- Interpreting the WI
- Absolute and effective permeability
- End point saturations and effective permeability
- Relative permeability
- Permeability to water
Relative Permeability Curves
- Steady State Method
- Unsteady State Method
- Corey Exponent
Interpreting Relative Permeability
- Producing from the transition zone
- Consequences for fluid sampling
- Basin centre gas
- Is SCAL really necessary?
- Alternatives to SCAL and value of information
Who Should Attend and Prerequisites
The course is designed for anyone interested in the application of SCAL, whether as a geologist, petrophysicist, or reservoir engineer. Familiarity with basic petroleum geology and engineering is assumed. Participants should be able to define the basic petrophysical properties: porosity, permeability, and saturation, how these are measured, and understand how these relate to in-place volumes. Special core analysis produces numerical data and understanding the measurements and applying them requires some basic mathematical skills.
Martin Kennedy, is a consultant petrophysicist based in Perth, Western Australia. He began his career as a wireline-logging engineer. After leaving the field, Kennedy worked in R&D, for government and for several mid-sized British independents before moving to Perth as Woodside’s Chief Petrophysicist in 2003. He left after six years to concentrate on training and consulting. His career has spanned everything from field studies to quick-look evaluations as well as managing the petrophysics skill-pool for two companies. Kennedy has worked on most of the classic petroleum provinces outside North America (and a few within) as well as some more exotic areas. He now consults for a wide range of companies ranging from small Independents to Majors and specializes in areas that do not readily yield to standard techniques. His particular interests are carbonates; the way logging tools interact with geology; image logs; and interpreting old logs, bad logs, and bad/old logs. Kennedy holds a degree in chemistry from Bristol U. and a PhD degree in electrical engineering from Edinburgh U.
Affiliations ans Accreditation
PhD Edinburgh University - Electrical Engineering
BSc Bristol University - Chemistry
N003: Geological Interpretation of Well Logs
N030: Rocks & Fluids: Practical Petrophysics (Isle of Wight, England)
N360: Quantitative Log Analysis and Petrophysics