Theoretical basis and methodology for geological risk assessment

Relevance and state of knowledge.
Historically abrupt fluctuations in energy prices led to the cyclic exploration activity of oil companies. At high prices actively developing petroleum industry could invest into expensive projects (deep-sea, arctic, unconventional hydrocarbons (HC), etc.). As long as prices for them remained high, not only operating expenses were covered, but also inevitable losses from unsuccessful exploration work. However, the sharp drop in energy prices radically changed the situation. Given the consistently high cost of hydrocarbons, companies had and still have to make great efforts to work within the framework of economic profitability and continue exploration work to replenish hydrocarbon reserves. And in this regard, an objective risk assessment is becoming the most important task for planning effective geological exploration. The problem of risk assessment in exploration works lies in the long-term nature of the latter. Namely, the projects planned today and the geological risks assessed in them in practice are confirmed only after years. In this regard, companies need a stable risk assessment policy to avoid chaos and randomness. Therefore, the development of a unified methodology, based on a theoretical concept, which the company(s) could use consistently for decades, is relevant all over the world. This issue is of particular importance in Azerbaijan. Prospecting and exploration work here is entering a new phase and is aimed at poorly studied complexes (Miocene, Paleogene, Mesozoic, foothill zones, etc.), which is associated with an increased risk. All this requires the most objective and effective risk assessment methods.

Another serious risk factor during operations is natural geological disasters, which can pose a serious threat to life, health of people and the environment, equipment and structures. The 2010 disaster at Macondo Square in the Gulf of Mexico, and the global financial loss from BPs response to its consequences, reminded the industry of the consequences of neglecting geological risks to minimize potential financial and human losses.

Object and subject of the research.
The object of the research is hydrocarbon exploration, the subject – risk assessment methods in this process.

The purpose and objectives of the work.
The aim of the work is to create a unified theoretical basis for assessing geological risks, and on its basis the development of a methodology for their assessment at various stages of exploration, as well as risks associated with natural hazards. The tasks to be solved can be formulated as follows:
  1. Development of a theoretical basis for geological risks assessment.
  2. Building a methodological framework for risk assessment for different types of basins
  3. Development of a methodology for evaluation of exploration risks on a basin-wide scale
  4. Creation of an algorithm for geological risks assessment
  5. Development of a methodology for evaluation of risks associated with the results of numerical modeling
  6. Construction of risk maps for various components of HC systems for the South Caspian basin
  7. Development of a methodology for assessing geological risks in individual prospecting and exploration areas
  8. Quantitative assessment of risks associated with geological hazards in the South Caspian during operational work

Research methodology and factual material.
The study is theoretical and methodological in nature. The research was carried out in two directions: 1) analysis, systematization and generalization of published data and 2) construction of new geological, geological and mathematical models, less often the use of ready-made models. As factual material, we used geological-geophysical and geochemical data for various basins. Unfortunately, not all examples could be shown in the thesis for confidentiality reasons

Protected provisions:
  1. Updated theoretical basis for geological risk assessment
  2. Methodology for geological risk evaluation at various stages of exploration work
  3. Results of the geological risk assessment for the Caspian region
  4. Methods of quantitative evaluation of geological hazards in the rapidly subsiding basins

Scientific novelty of the work:
  1. The theoretical foundations for assessing geological risks based on the method of mixtures of distributions of random variables and the theory of random processes have been developed
  2. Identified the most significant risk parameters for the existence of HC systems in the main types of sedimentary basins of the world
  3. For the first time, a method for assessment of the number of undiscovered hydrocarbon deposits was developed and the exploration risks in Azerbaijan were evaluated.
  4. A new methodology for evaluation of the yet-to-find resources in oil and gas basins has been developed and the potential of the Productive Thickness (PT) for the onshore and offshore Azerbaijan has been assessed
  5. Comprehensively summarized and visualized the processes of building risk maps based on the study of depositional environments (Common Segment Risk Maps)
  6. For the first time, a numerical method for evaluation risks associated with the basin modeling results has been developed.
  7. For the first time, methods for assessing risks associated with accumulated hydrocarbon volumes have been developed.
  8. For the first time, the risks of sealing capacity and hydrocarbon migration routes in the South Caspian were evaluated
  9. A methodology for assessing geological risks for prospects using probabilistic mathematical methods has been developed.
  10. A comprehensive methodology has been developed for the use of geological risks in economic risk analysis (assessment of the value of seismic information, working interest under a fixed budget)
  11. Methodological foundations for quantitative geological hazard assessment have been developed

The theoretical and practical value of the work.
Suggested theoretical basis of the risk assessment can be applied at any branch of geological sciences. For more than 20 years, the author has worked in the worlds leading oil companies: ConocoPhillips, BHPBilliton Petroleum, BP, SOCAR, where all these methods were introduced and tested in specific projects in various basins of the planet and continue to be applied by SOCAR geologists. The developed methods for the comprehensive assessment of resources are the main tool for assessing risks in prospecting and exploration work at SOCAR.

Studies in the geological hazard assessment were used by oil companies-operators when planning work in Azerbaijan (primarily in the Caspian Sea). These were the first works in this area.

Download the abstract

02.11.2021     Print  Print