Climate Stratigraphy

Principles and Applications in Subsurface Correlation

image of Climate Stratigraphy

One of the most important steps in oil and gas is the construction of a near-synchronous high-resolution stratigraphic framework. This stratigraphic framework forms the basis in the search for additional potential reservoirs and especially in reservoir characterization. Many reservoir intervals are barren of fossils, and conventional stratigraphic methods often lack the required level of resolution. An alternative stratigraphic approach is to use the climate record stored in the sedimentary rock record and subsequently recorded by facies-sensitive wireline logs. The science behind this approach is climate stratigraphy, which is a relatively new discipline combining advanced numerical processing of conventional log data with the theory of climate-driven cyclicity in sedimentary depositional systems.

Extraction of the climatic signal from facies-sensitive wireline logs allows the construction of a high-resolution stratigraphic framework for both reservoir and regional scale correlation, more or less independently of other stratigraphic data. It is therefore a highly cost-effective and universally applicable method deserving of wider appreciation and use.

These course notes include a discussion on the theory of climate changes and its effect to sedimentary facies and its relation to the stratal pattern architecture in the subsurface. This is followed by an extensive explanation of spectral analysis of facies-sensitive wireline logs and the transformation of logs. These log transforms or spectral attribute curves are used in well correlations for the construction of a near-synchronous stratigraphic correlation framework. The book is highly illustrated and it includes several examples from clastic as well as carbonate reservoir correlations.

Table of Contents

Chapter 1 – Introduction

Chapter 2 – Orbital forcing of climate change

History of orbital-forcing hypothesis
Insolation and circulation of the atmosphere
Orbital controls on insolation
Orbital modelling and computation
Verification of the Milankovitch hypothesis – Examples from the Quaternary
Examples in the ancient record
Applications in chronostratigraphy

Chapter 3 – Global cyclostratigraphy
Global cyclostratigraphy - principles
The earth’s response to changing insolation
The phases of a climatic cycle
Climate succession by cyclostratigraphic belt
Predicting basin-fill from the cyclostratigraphic model

Chapter 4 – Deterministic modelling and analysis of wireline log data
Facies-sensitive wireline logs
Wireline logs as data
Some basic assumptions
Properties of simple and composite waves
Waves and oscillating processes in the time and depth domain
Composite waveforms and principles of spectral analysis
Transformation of logs
Maximum Entropy Method (MEM) and Maximum Entropy Spectral Analysis (MESA)
Examples of Maximum Entropy Spectral Analysis (MESA) from the subsurface
Spectral Change Attribute analysis (PEFA)
Some basic principles of PEFA
Effects of discontinuity
Spectral Change Attribute analysis (PEFA) – applications to the subsurface
Spectral Change Attribute analysis (PEFA) – examples from the subsurface
The Spectral Trend Attribute (INPEFA) curve
Spectral Trend Attribute (INPEFA) curve – definitions and interpretations
The INPEFA trends
The INPEFA turning points
Long-term and short-term Spectral Trend Attribute (INPEFA) curves
Spectral Trend Attribute curve (INPEFA)
Geological interpretation of INPEFA with examples from outcrop and cores

Chapter 5 – Working concepts and subsurface correlation
From cyclic sedimentation to global cyclostratigraphy and climate stratigraphy
Hierarchy of stratal units and geological dimensions in climate stratigraphy
Climate change expressions from outcrop examples
Subsurface correlations
Clastic examples
Carbonate examples

Chapter 6 – Bibliography and references
Books and collections of papers
Review papers
References used



This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error