Petroleum Geochemistry


Application of geochemical techniques to oil and gas exploration provide increased understanding of hydrocarbon generation, migration, and accumulation processes within a basin prior to drilling. As more samples become available, geochemical techniques can outline complex basin filling histories, explain unusual oil and gas distributions, and identify the sources of oil and gas. When considered against random drilling, geophysics (trap size) alone provides a forecasting efficiency of 28%, while geophysics in conjunction with geochemistry provides a forecasting efficiency of 63% for locating hydrocarbons during exploration (Sluijk and Parker, 1986).Petroleum geochemistry has proven to be an effective and inexpensive tool for reducing exploration risks.

In applying petroleum geochemistry to exploration problems, a major focus is the analysis and interpretation of the compositions of the complex hydrocarbon fluids and source rock. The composition of oil and gas is dependent on many factors, including the type of organic matter, the source maturity, the migration distance, the characteristics of the carrier bed, and post accumulation processes such as biodegradation, leakage, thermal stress and water-washing. Each of these processes establishes or alters the fluid composition in predictable ways. Fluid composition can be used to detect and characterize these processes.

Source Rock Analysis

  1. Screening Analysis
    1. Total Organic carbon (TOC %)
  2. Rock Eval Pyrolysis
  3. Organic Petrography
  4. Detailed Hydrocarbon Analysis (Sample Preparation)
    1. Extraction of Organic Matter (EOM) by Soxhlet Extraction
    2. Deasphaltation
    3. Chromatographic Separation of Fractions
  5. Detailed Hydrocarbon analysis
    1. Saturated & Aromatic Hydrocarbon Analysis by GC-FID
      1. Light Hydrocarbon Analysis
      2. Crude Oil
      3. Heavy Crude Oil
      4. Applications
    2. Biomarker Analysis by GCMS
    3. Aromatic Hydrocarbons by GCMS
    4. Diamondoid Analysis by GCMS
    5. Seep Analysis