Petrophysics in Carbonate Reservoir

It is estimated that more than 60% of the world’s oil and 40% of the world’s gas reserved are held in carbonate reservoir. Carbonates exhibits varying properties making it difficult to characterized. A focused approach is needed to better understand the heterogeneous nature of rock containing fluids and the flow properties within the porous and often fractured formation. This involves detailed understanding of the fluid saturation, pore-size distribution, permeability, rock texture, reservoir rock type and natural fracture systems at different scales.

During this course, the concepts of petrophysical rock properties such as porosity and permeability and mineralogy in carbonate reservoirs will be covered. The relationships between these parameters and in situ fluid saturation will be discussed.

The physics of well logging tools to methods of interpretation of these parameters will be applied. The understanding of acceptable well log quality and the recognition of good well log data will be addressed.

This course is prepared to provide the interpretation, concepts and techniques for carbonate reservoirs on which to develop the petrophysical knowledge and apabilities necessary for geologists, geophysicist, engineers and petrophysicist. The understanding of acceptable well log quality on tool measurements, data handling and the recognition of good well log data will be addressed.

Practice application on carbonate reservoir examples will be used as workshop training for quick look interpretation. The case studies for lithofacies identification, bitumen detection variable parameters in heterogeneous carbonate reservoirs from log data will be studied in this course

• Understand concepts of petrophysical rock properties in carbonate reservoirs
• Acquire knowledge on lithofacies in carbonates and porosity determination
• Discussion on fractures, vugs and bitumen detection in carbonates
• Determine and understand core and core analysis
• Learn and practice on interpretation concepts
• Understand saturation using Archie’s equation and permeability determination from logs and cores
• Identify petrophysical parameters evaluation from core and log data
• Knowledge on log quality control on tool measurements (log readings) and data handling
• Practice application on carbonate reservoir examples
• Learn quick look interpretation using advanced methods and cross-plots

• Petrophysicists and Well Logging Analysts
• Geoscientists; Geologists and Geophysicists
• Petroleum, Drilling and Reservoir Engineers,
• Whose job requires knowledge of petrophysical engineering in carbonate reservoir

DAY 1

Course target and expectation

Reservoir and rock properties

Resevoir parameters

• Porosity
• Saturation
• Permeability
• Permeability and Porosity Relationships

Logging Tools Measurements:

• Planning
• Operation
• Logging Environment
• Tool Calibration

Open-Hole Logging Tools & Measurements

• Lithology Tools
  • Mud Logs
  • Gamma Ray & Practical Session (GR)
  • Spectral Gamma Ray & Practical Session (Spectral GR)
  • Spontaneous Potential & Practical Session (SP)
  • Caliper Logs
• Porosity Tools:
  • Sonic Logs & Practical Session (Sonic)
  • Density Logs & Practical Session (Density)
  • Neutron Logs & Practical Session (Neutron)
• Resistivity Tools:
  • Laterolog & Practical Session
  • Induction Logs & Practical Session
  • Micro-Spherical Logs (MSFL) & Practical Session Invasion Profile

Case study:

• To differentiate between types of Porosity
• To differentiate between methods for Volume of Shale (Vsh) calculation

Exercise: To calculate the petrophysical parameter

DAY 2

• Petrophysical Parameters:
  • Core and Core Analysis: ‘a’, ‘m’ and ‘n’ Determination from SCAL
  • Determination of ‘Rw’ from formation water samples
  • Most problematic parameters
• Quick Look Interpretation :
  • Quick Look Methods
  • Lithology Determination from logs
  • Rw Determination Method
  • Quick Look Interpretation for Porosity ‘m’ from core measurements
  • Volume of Shale Estimation
  • Basic Relations for Water Saturation Estimation
  • Permeability from logs
• Practical Application Examples (Workshop)
  • Practice application on carbonate reservoir examples for quick look interpretation using excel files

Case study: How to calculate the petrophysical parameters

DAY 3

Recent & Advanced Tools:

• Geological Tools
  • Fullbore Formation
  • Microscanner Imager
• Other Tools
  • Nuclear Magnetic Resonance
  • Modular Dynamic Tester

Logging While Drilling (LWD)

• Lithology Tools
• Porosity Tools
• Resistivity Tools

Cased-Hole Logging Tools:

• Thermal Decay Time
• Cement Bond
• Production Logging

Case study:

• The FMI log example to define the structural elements in the presented reservoir.

Exercise:

• To differentiate between these different structural elements.

Case study:

• Using the CMR log example to differentiate bound fluid and free fluid

Exercise:

• To define where we can perforate against the free hydrocarbon and away from the bound fluid

Case study:

• Using the RFT / MDT log example to determine reservoir pressure, reservoir permeability, formation fluid contacts and verify reservoir isolation

Exercise:

• To differentiate between the different gradients of different types of fluids

DAY 4

To complete the cases studies and exercises of TDT/RST, CBL/VDL and PLT Cased-Hole Logging tools from Day 3

Case study:

• Using the TDT / RST log example to determine the formation water saturation in cased-hole.

Exercise:

• To calculate the formation water saturation (Sw) from TDT log example.

Case study:

• Using the CBL / VDL log example to evaluate zone-to-zone isolation, etc.

Exercise:

• To determine the good and poor cement bonds.

Case study:

• Using the PLT log example to evaluate perforation are plugged

Exercise:

• To determine which perforation are plugged

Formation Evaluation:

• Porosity Types
• Fluid Saturation
• Permeability
• Permeability and Porosity Relationships
• Core Analysis and Core-Log Relationships
• Archie’s Relationship

Advanced Formation Evaluation for Reservoir Petrophysical Model Evaluation Modern Approaches and Techniques in Petrophysics:

• Multi-Well Bases Study using multi-well data-base, key well study, data normalization, variable petrophysical parameter values and standardization of petrophysical parameters

Petrophysical Parameters Determination:

• Archie’s Parameters, Most Problematic Parameters, Old Methods (Constant Value) and New Methods (Variable Values).

Computer Processed Interpretation (CPI) Log Quality Control

• Log data Quality Control and data selection, LQC on output processing parameters and digital data format

Case study: How to evaluate the Lithology and how to calculate the petrophysical parameter
Exercise: To calculate the fluid saturations

DAY 5

To review examples of the different digital data in different formats (LAS, DLIS, LIS, ASCII, etc.) for example well.

• Lithofacies Identification:
  • Lithofacies Identification in carbonate reservoirs using log measurement data and core analysis data
• Bitumen detection
  • Bitumen detection in carbonate reservoirs using log measurement data and core analysis data with the application of the created Data-Base
• Variable Parameters Study
  • Variable parameters study in heterogeneous carbonate reservoirs as variables “m” and “Rw” for accurate saturations estimation
• Permeability Prediction in Carbonate Reservoirs
  • Permeability prediction from log data by using it’s relation with core data to be applied in wells without cores.

Case study: Constant problematic petrophysical parameters (‘Rw’ and ‘m’) and petrophysical parameters using core and log data

Exercise: To calculate the constant and variable problematic petrophysical parameters (‘Rw’ and ‘m’)