OPTICAL KEROGEN ANALYSIS

Integrated optical analysis of kerogen composition, preservation and maturation for improved evaluation of hydrocarbon potential

Benefits for HC Exploration

  • Detailed quantification of each single kerogen type within the total kerogen
  • Quantification of productive versus unproductive proportions of the total kerogen
  • Quantification of oil-prone vs. gas-prone kerogen within the productive kerogen
  • Detailed analysis of preservation of each kerogen type – estimation of HC generation from oil-prone and gas-prone parts of kerogen
  • High resolution analysis of organic maturation by two independent methods
  • Detailed palaeothermal history and HC maturity
  • Identification of different kerogens with different HC potential mixed within the total kerogen

Overview

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Kerogen Composition

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Kerogen Preservation

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Kerogen Maturation

Add Ons for integrated source rock analysis

Optical Kerogen Analysis – integrated analysis of kerogen composition and preservation for enhanced evaluation of hydrocarbon potential
Core Logging and Thin Section Analysis – texture and composition of source rocks (organic rich shales)
SEM ANALYSIS – high-resolution analysis of microporosity (kerogen and rock-matrix), rock texture and mineral/kerogen distribution and quantification
Clay Mineralogy and Carbonate Quantification – information on petromechanical properties and quantification of swellable vs. non-swellable clay minerals

Kerogen Composition

Kerogen is isolated from the rock and directly studied under the microscope, using techniques for optical kerogen analysis from academic research (palynology / palynofacies). Optical quantification of palynologically defined kerogen groups and transformation to kerogen types. Highly sensitive quantification of each kerogen type seperately in each sample, improving evaluation of primary generated types of hydrocarbons.

Identification of mixed kerogen, regarding mixed composition, preservation & maturation. Quantification of productive vs. unproductive proportions of the total kerogen data can be implemented directly into organo-facies based HC system modeling. Optical kerogen analysis is a strong improvement to chemical kerogen analysis (Rock Eval, Biomarker), based on bulk rock analysis, which is unable to identify mixed kerogen and its effect on chemical parameters and can mislead interpretation of chemical analysis of HC potential.

Kerogen Preservation

Primary degradation = microbial and chemical alteration of kerogen during transport, deposition and early diagenesis. Secondary degradation = alteration related to increasing maturation of kerogen during burial / secondary heating and hydrocarbon generation.

Maturation related degradation indicates levels of hydrocarbon generation from actual kerogen. Kerogen preservation correlates directly to microporosity of kerogen, linked to storage capacity for unconventional shale gas and oil.

Provides detailed information on hydrocarbon generation and storage capacity (for unconventional plays).

Kerogen Maturation

Combination of two independant methods – vitrinite reflectance (VR) and palynomorph colour indices (SCI/TAI) – for maximum reliability and accessibility of maturation data.

VR as standard method, provide precise  and maturation trends. New high-resolution VR analysis using grey scale analysis of digital vitrinite images, eliminating mixed reflectance typical for classical VR analysis.

SCI & TAI, providing short term first estimates of maturation levels. SCI & TAI used for independent chross-check of VR data and when vitrinite is missing (by facies, preservation or stratigraphical limitation).

For more details see Integrated Organic Maturation.