Ph.D. Theses

Isotopic geochemistry of mud volcanoes fluids of the Shamakhy-Gobustan and Lower Kura regions in connection with the assessment of oil and gas perspectives

Applicant: Ayten Bakhtiyar Huseynova

Specialty: 2521.01 – Geology, search and exploration of oil and gas fields

Relevance and state knowledge of the topic
Mud volcanism is a natural process closely related to the formation of oil and gas fields. Identification of the conditions of their formation by using modern isotope-geochemical methods allows to supplement our knowledge of these processes.

The first geochemical studies of hydrocarbon gases (HCG) in Azerbaijan began in the early XX century and continue to this day. The chemical composition of HCG fields was studied firstly by such prominent scientists as K.V.Kharichkov, S.A.Kovalevsky, V.V.Weber, A.A.Potolovsky, V.S.Buinitsky, Y.G.Mamedaliev, D.N.Ibadov, D.V.Zhabrov, V.S.Melik-Pashaev, F.G.Dadashev and many others. The study of gases, allowed to identify the relationship between the chemical composition and geological factors. Azerbaijani scientists made a great contribution to the study of gases: F.G.Dadashev, S.G.Salayev, I.S.Guliyev, A.A.Feyzullayev, A.I.Aliyev, R.A.Huseynov, A.Y.Kabulova, A.M.Dadashev and others. The isotope studies of hydrocarbon gases were started comparatively recently in the end of 70s and beginning of 80s of the XX century by A.A.Yakubov, Ad.A.Aliev, A.Y.Kabulova, A.A.Dadashev, B.M.Valyaev, I.S.Guliev, A.A.Feyzullaev, D.A.Huseynov, A.Mazzini, Etiope, etc.

By now, a considerable scope of isotopic-geochemical investigations has been carried out, but the absence of generalized materials and, as a consequence, the absence of a full scope of information needed for geochemical interpretation, does not allow to assess the regional potential more correctly.
Isotope studies of gasses released from mud volcano systems are a useful tool to understand a numerous ongoing processes (e.g., connection with oil and gas content, internal structure, role in the greenhouse effect, etc.).

More than five hundred mud volcanoes have been identified onshore and offshore in Azerbaijan according to data on 2015. During more than two-hundred-years of Azerbaijan oil industry development, more than 70 oil and gas condensate fields have been discovered within Azerbaijan, many of which host mud volcanoes. At these sites, the focused seepage of deep sourced fluids, provides crucial information for processes ongoing at great depths of this thick sedimentary basin.

Object and subject of the research

The object of the dissertation work is the process of mud volcanism. The subject of the dissertation work is mud volcanoes fluids of Azerbaijan.

Purpose and objectives of the research
Identification of patterns of changes in isotope-geochemical parameters of mud volcanoes of Shamakhy-Gobustan and Lower Kura regions, identifying the conditions of fluid formation on the set of data and evaluation of oil-and-gas-bearing prospects.
  1. Carrying out field studies after mud volcanic eruptions in the Shamakhy-Gobustan, Lower Kura, Pre-Caspian-Guba and Absheron regions;
  2. Fluid sampling after eruptions from mud volcanoes in the regions of interest and their analysis;
  3. Carrying out geomorphological mapping of mud volcanic flows, creating 3-D models;
  4. Creation of geological and geochemical database and its statistica analysis;
  5. Identification of patterns in the distribution of isotopes in mud volcanoes fluids;
  6. Analysis of seismological data received after MV eruptions;
  7. Estimation of gas emission volumes during eruptions based on Sigma Flow software package and statistical analysis of their frequency;
  8. Revealing the conditions of fluid formation and assessment of the prospects of oil and gas potential within the study areas.

Research methods
The research of the dissertation work was based on the data concerning isotonic-geochemical characteristics of mud-volcanic fluids of the Shamakha-Gobustan and Nizhnekurinsk districts received during field studies and completed by the previously published data. Sampling in the field was carried out with in situ measurements of such parameters as temperature, oxidation-reduction potential, water pH, etc. The composition of mud volcanic gas was investigated on a Crystal M 2000 chromatograph, the isotopic composition of water and carbon-containing components on a Delta-V-Advantage mass spectrometer, a Trace-GC-Ultra chromatograph and a Finnigan-TC/EA analyzer.

The basic provisions giving to the defense
  1. The trends in the distribution of isotopic-geochemical parameters of mud volcanoes fluids;
  2. Identification of formation conditions of mud volcanoes fluids in the Shamakhy-Gobustan and Lower Kura regions based on a complex of geological-geophysical and geochemical data;
  3. Assessment of the hydrocarbon potential within the research areas.

The scientific novelty of the research
  1. New data about isotopic geochemistry of fluids from mud volcanoes after eruptions were obtained (δ13СС1, δ13CCO2; δ18О; δDC1, δ15N);
  2. Nitrogen isotopic composition of mud volcanoes gases, where the range of values depends on geological conditions;
  3. The isotopic-geochemical model of fluids from mud volcanoes has been improved and is used to assess the potential depths of gas and water generation (for gas: 5-7 and 12-14 km, for water: 3-6 km).

The theoretical and practical significance of the research
The theoretical significance of the work is to reveal the conditions of formation of mud volcanic fluids. Practical significance is in determining the depths of mud volcano fluid generation by isotopicgeochemical and seismological data.

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