Hesabatlar

EXECUTIVE SUMMARY

Azerbaijan contains numerous mud volcanoes which emit breccias, water, gas and oil films. The study of mud volcano emissions yields useful imformation about sedimentary deposits at the depths which are not available from conventional drilling.

The proposed report contains the results of new research compiled by a team of scientists in the Geology Institute of Azerbaijan Academy of Sciences and the BP/Statoil Alliance. This research describes 16 typical mud volcanoes from three oil-gas regions: Shemakha-Gobustan, Lower Kura and Apsheron. The report consists of four volumes and contains:


General information regarding mud volcano evolution including:

• recent maps of mud volcano activity in Azerbaijan (onshore and offshore) constructed on topographical, geological and tectonic bases corrected with the use of satellite imagery;
• maps of heat flow distribution in Azerbaijan prepared from satellite surveys through time;
• regional tectonic profiles illustrating the structure of mud volcano areas;

complex data on each of the 16 mud volcanoes, including the information on geomorphology, tectonic structure, geological situation, temperature regime, the results of isotope and geochemical research of gas, oil, water and organic matter, and the mineralogical-geochemical analysis of breccias.

The report is well illustrated by coloured photos of the studied mud volcanoes.

CONTENTS

(i) Preface
(ii) List of Contents

1 INTRODUCTION AND OVERVIEW

1.1 The Importance of Studying Mud Volcanoes1.2 World Wide Occurrence of Mud Volcanoes1.3 Geology and Mud Volcanoes of Azerbaijan1.4 Classification of Azerbaijan Mud Volcanoes1.5 Methods of Investigation

2 FIELD INVESTIGATIONS

2.1 Introduction2.2 Demirchi2.3 Matrasa2.4 Charagan2.5 Melikchobanly2.6 Kyrlykh (Geilyarsk)2.7 Shikhzairly2.8 Pirekeshkyul2.9 Cheildag2.10 Airantekyan2.11 Dashgil2.12 Bahar2.13 Akhtarmaady2.14 Akhtarma Pashaly2.15 Kyrlykh Kharaminsk2.16 Lake Kyrlykh2.17 Shorbulag2.18 Lokbatan2.19 Angecharan reservoir outcrop section

3. SATELLITE THERMAL STUDY

3.1 Summary3.2 Introduction3.3 Analysis of Data3.4 Interpretation of Thermal Data3.5 Concluding Remarks3.6 References

4. DISCUSSION AND CONCLUSIONS

4.1 Origin of Mud Volcanoes4.2 Origin of Oil and Gas Seepage from Mud Volcanoes4.3 Oil-Source Rock Correlations4.4 Mud Volcano Waters4.5 Concluding Remarks

APPENDIX 1

1.1 A Review of Mud Volcanism / World Mud Volcanoes Databank1.2 Catalogue of Recorded Mud Volcano Eruptions in Azerbaijan, 1810 - 19921.3 All about Mud Volcanoes a Draft Version, Excluding Illustrations, of a Laymans Guide1.4 Key Papers, Including English Translations, on Mud Volcanism and the Mud Volcanoes of Azerbaijan1.5 Field Guide for the 1992 Expedition to Investigate the Mud Volcanoes of Azerbaijan

APPENDIX 2

2.1  Geological Characteristics of Regions of Mud Volcano Development in Azerbaijan2.2  Tectonics of the Area of Mud Volcano Development in Azerbaijan2.3  Explanatory Note to the Map of Mud Volcanoes in the South Caspian Sea2.4  Classification of Mud Volcanoes and Their Eruptions2.5  Description of 17 Studied Mud Volcanoes2.6  Biostratigraphic Results2.7  Characteristics of the Rocks - Age and Lithology2.8  Lithological and Mineralogical Study of Material Erupted from Mud Volcanoes2.9  Results of XRD Studies of Samples of Breccia from Mud Volcanoes in Azerbaijan2.10 Results of DTA of Clays from Mud Volcanoes in Azerbaijan2.11 Thermal Characteristics of Mud Volcanoes2.12 Satellite Thermal - Calibration Data2.13 Structural Interpretation of Satellite Images of Zones of Mud Volcanoes and Analysis of Mud Volcano Distribution on the Basis of Satellite

APPENDIX 3

3.1  Geochemical Study of Organic Matter in Rocks Erupted from Mud Volcanoes3.2  Brief geochemical Description of the Oils of Azerbaijan3.3  Carbon Isotopes of Oils3.4  Geochemical Composition of Oils from Mud Volcanoes in Azerbaijan from Infra Red Spectroscopy Data3.5  Carbon dioxide in Mud Volcano Gases3.6  Description of mud volcano waters3.7  Mud Volcano Project - Preliminary Geochemical Data for Oils, Source Rocks and Gases (Samples Collected October 1992)3.8  List of Samples Collected and Analysed3.9  Geochemical Analysis of Outcrops, Oil Seeps and Gases from Mud Volcanoes, Azerbaijan3.10 Geochemical Data for Thirteen Oils from Azerbaijan, Georgia and Turkmenia

EXECUTIVE SUMMARY

The main objectives of this study have been to investigate the vertical extent of oil window to aid future exploration of deeper horizons in the Lower Kura Depression. Additionally, determinations of possible source rocks that contributed to oil accumulations, timing of oil generation from these source rocks and characterization of petroleum occurrences in the study area have been investigated.

In this study, we approach the problem by utilizing detailed organic geochemistry of oils and available source rocks (from boreholes and rocks ejected from mud volcanoes) and computer-aided modeling which simulates physico-chemical and geological processes.

Detailed organic geochemical data on 26 crude oil samples from nine oil fields and some hydrocarbons extracted from the rocks of the Eocene-Pliocene sequence in the Lower Kura Depression of the South Caspian Basin are presented.

Oil accumulations seem to be associated with all of the potential reservoir rocks within the Miocene-Quaternary stratigraphic sequence which consists of alternating shale (siltstone) sand beds of a typical prograding delta. Paleogene and Cretaceous rocks, lying at depths greater than 6-6.5 km, have not been penetrated by drilling; however, they have been brought to the surface by mud volcano activities. This provides a unique opportunity to study the organic geochemical properties of these older units.

CONTENTS

(i) List of Tables
(ii) List of Figures

1. INTRODUCTION AND AIM OF STUDY

2. GEOLOGY

2.1 Geologic Setting2.2 Stratigraphy2.3 Structural Geology2.4Mud Volcanoes

3. PETROLEUM GEOLOGY
 

3.1 Source Rocks3.2 Reservoir Rocks3.3 Traps3.4 Oil Fields

4. PETROLEUM GEOCHEMISTRY
 

4.1 Samples and Analytical Methods4.1.a Rock Eval Pyrolysis and LECO TOC4.1.b Visual Kerogen Analysis4.1.c Vitrinite Refelectance Analysis4.1.d Sulfur Analysis4.1.e Geochemistry of Oils and Soluble Organic Matter (SOM)4.1.e.1 Gas Chromatographic (GC) Analysis4.1.e.2 Gas Chromatography-Mass Spectroscopic (GC-MS) Analysis4.1.f Carbon Isotope and Infra-red Spectroscopic Analyses of Gases and Oils4.2 Results and Discussion4.2.a Potential Hydrocarbon Source Rocks4.2.b Type of Organic Matter and Source Rocks Facies4.2.c Thermal Maturity of Oils and Potential Source Rocks4.3 Summary and Conclusions

5. BASIN MODELING
 

5.1 Outlines of the Modeling Approach and Modeled Wells5.2 Conceptual Model and Input5.2.a Boundaries of Study Area5.2.b Events and Layers5.2.c Paleobathymetry and Sediment/Water Interface Temperatures5.2.d Heat Flow Considerations5.3 Simulation Results and Interpretation5.3.a Burial History5.3.b Thermal History5.3.c Maturation History5.3.d Hydrocarbon Generation History5.4 Summary and Conclusions

6. CONCLUSIONS

7. RECOMMENDATIONS FOR FUTURE RESEARCH

REFERENCES

TABLES

FIGURES


APPENDICES

1. Structural Maps
2. GC-Chromatograms and Mass Fragmentograms of Oils and Bitumens

EXECUTIVE SUMMARY

The territory of Azerbaijan is situated on the tectonically active geosyncline folded region, characterized by high seismicity and broad development of mud volcanism. Without analysis of the continual evolution of these factors in space and time, the precise choice of the place, on which a platform will be installed during the exploitation of oil and gas sediments and the positioning of pipeline routes in the sea, is impossible.

The aim of the proposed report is to conduct hazard analysis and to evaluate the probability of volcanic eruptions and of earthquakes sea at any moment.

In the report, the results of many - factores static data processing for earthquakes in Azerbaijan during 1932-1990, and of volcanic eruptions for last 100 years, are given.

The hazard analysis of the Chirag area in the Caspian Sea is given.

Detailed methods can be used for planning and installing platforms as well as for positioning pipelines in any reservoirs.

CONTENTS

INTRODUCTION

1. MATHEMATICAL BASIS FOR SOLVING PROBLEMS RELATED TO THE EVALUATION OF THE HAZARD PRESENTED BY OCCURRENCES OF MUD VOLCANISM AND SEISMIC ACTIVITY

1.1 Main Concepts in Probability Theory1.2 Main Distributions and Conclusions Used During the Project1.3 Main Mathematical and Statistical Concepts and Facts Used During the Project1.4 Testing of Statistical Hypotheses1.5 One problem With the Discovery of "Disorder" in Multiple Random Processes1.6 Cluster Analysis

2. ASSESSMENT OF RISK ASSOCIATED WITH MUD-VOLCANO ACTIVITY

2.1 The Probability of a New Mud Volcano Developing in a Specific Area (Chirag)2.2 Investigation of the Distribution of Distances of Individual Groups of Gryphons from a General Eruptive Centre2.3 Prediction of the Waiting Time and Frequency of Mud-Volcano Eruptions in the Chirag Area2.4 Analysis of the Relationships of Variables Related to Mud-Volcano Eruptions2.5 Investigation of the Distribution of Variables Associated with Mud-Volcano Flows2.6 Investigation of Factors Associated with the Emission of Combustible Gases2.7 Study of the Probability of Fracture-Formation Accompanying the Processes of Mud-Volcano Eruption

3. INVESTIGATION OF SEISMIC HAZARD TO OFFSHORE HYDROCARBON-INDUSTRY INSTALLATIONS IN THE CHIRAG AREA

3.1 Investigation of the Frequency Distribution of Major Earthquakes, and Their Intensity3.2 Investigation of the Directional Distribution of Longitudinal Earthquake Waves3.3 Investigation of the Occurrence of Seismic Dislocations, Their Causes, and Their Spatial Orientation3.4 Methodology for Assessing the Seismic Threat to Individual Foundations During Drilling, Allowing for Acoustic Rigidity

4. INVESTIGATION OF THE PROBABILITY OF HAZARDOUS EVENTS ASSOCIATED WITH THE INTERRELATED ACTIVITY OF SEISMICITY AND MUD VOLCANISM

CONCLUSIONS AND RECOMMENDATIONS

MAIN CONCLUSION

REFERENCES

LIST OF TABLES

LIST OF FIGURES

EXECUTIVE SUMMARY

The study has analysed 64 oils from the main hydrocarbon producing areas of Azerbaijan. A full range of petroleum geochemical analyses has been carried out and the data interpreted in the light of the known petroleum geological setting of the fields in the area. Detailed analyses, including gas chromatography (GC), gas chromatography-mass spectrometry (GC-MS), and carbon isotope (CI), have enabled the characterisation and correlation of the oils. Based on limited available source rock analytical data, speculative oil to source correlations are made.

The area studied can be divided into two principal hydrocarbon provinces. Firstly, The Lower Kura- South Caspian area which includes the well known and extensively explored Baku and Apsheron areas. Secondly, the Middle Kura Depression which is an intermontane basin between the Greater and Lesser Caucasus Mountains.

The Lower Kura-South Caspian area contains thick, regional, sandstone deposits of Pliocene and Quaternary age. The sandstones of the Middle Pliocene Productive Series are the main reservoirs for hydrocarbons in this area and total thickness can reach 5000m. Oil fields often contain multiple oil-bearing horizons within the Productive Series. The vast quantity of sediment deposited in the rapidly subsiding Pliocene basin has led to massive overpressuring of underlying Palaeogene - Miocene mudstones which in turn has led to shale diapirism, massive scale expulsion of formation waters and generated hydrocarbons into the overlying Pliocene sands and often the formation of mud volcanoes. The overpressuring plays a significant role in the accumulation and fate of hydrocarbons in this region. Shale diapirism creates structural traps for the accumulation of hydrocarbons. Expulsion of formation water and hydrocarbons from the overpressured shales is the main driving force for hydrocarbon migration. Formation waters being moved through the sediment at high pressures and high temperatures dissolve the volatile compounds from hydrocarbons which may be encountered in reservoirs or may be migrating as part of the same expulsion mechanism.

The Middle Kura Depression did not undergo the rapid Pliocene subsidence of the Lower Kura-South Caspian area and consequently does not have the thick Middle Pliocene sandstone deposits of the Productive Series. The main reservoirs are fractured carbonates of the Upper Cretaceous or sandstones of the Palaeogene - Miocene.

Oils from the Lower Kura-South Caspian area appear to be generally a mixture of two oils from different sources, although occasionally the individual oils do occur unmixed. The first oil to migrate was a waxy oil which has been generated from middle mature Tertiary shales or mudstones which were deposited in a saline lacustrine environment. In most of the samples this oil has suffered moderate biodegradation. The second oil which has mixed with the waxy biodegraded oil is a light oil or condensate which has probably been generated from a type I or type II kerogen. This light oil has had significant quantities of the volatile hydrocarbons removed by water washing.

The generally low temperature gradients, rapid subsidence and late formation of the structures in this area imply that the alteration of the first oil and the migration and mixing of the two oil types has occurred most likely during the migration process. The subsequent water flushing of the second light oil may also have occurred during this migration process.

The abundant evidence of the active leakage of hydrocarbons at surface and the generally low gas to oil ratios are also evidence of high levels of current activity in migration. The great depths from which the oils have been sourced, the tectonic/migration activity and the high subsurface pressure make it extremely difficult to predict oil type quality between structures.

There may localised facies variations in the source rocks but generally there appear to be only two main sources of hydrocarbons in this area. Also there may be minor contributions on a local scale from dispersed organic matter in other horizons.

Oils which were analysed from the Middle Kura are all related. They are waxy oils generated from middle mature Tertiary shales or mudstones which deposited in a saline lacustrine environment. These oils are also related to the waxy oils found in the Lower Kura-South Caspian.

A lack of published data from potential source rocks in Azerbaijan and no samples for analysis in this study means that definite correlations between the oils and source rocks cannot be made. The main source rock in the South Caspian hydrocarbon province is considered to comprise shales of the Maykop Formation and it is probable that this is the source of the waxy oils analysed in this study. The light oil may have been generated by diatomaceous shales of Miocene age.

Localised facies variations may alter the physical nature of the oils but in the Lower Kura-South Caspian area, the main controls on the specific gravity and the mobility of the oils are the relative proportions of the light oil and waxy oil in the final mixed oil and the degree of biodegradation and water washing that has affected the oils.

CONTENTS

Volume 1: Text

1. SUMMARY

2. INTRODUCTION

2.1 Scope and Purpose of the Study2.2 Materials and Data Sources2.3 Analytical Methods2.4 Data Presentation

3. REGIONAL GEOLOGICAL SYNOPSIS

3.1 Physiography3.2 Geological History3.3 Tectonics3.4 Stratigraphy3.4.1 Pre-Mesozoic3.4.2 Jurassic3.4.3 Cretaceous3.4.4 Cenozoic3.5 Oil and Gas Occurrences3.6 Source Rocks3.6.1 Jurassic3.6.2 Upper Cretaceous3.6.3 Eocene3.6.4 Oligocene - Lower Miocene3.6.5 Pliocene3.7 History of Oil Exploration3.7.1 Summary3.7.2 Exploration and Production Figures

4. GEOCHEMICAL EVALUATION

4.1 Middle Kura Depression4.1.1 Introduction4.1.2 Geochemical Characteristics4.1.3 Conclusions4.2 Shemakhino Kobustanskiy Depression4.2.1 Introduction4.2.2 Geochemical Characteristics4.2.3 Conclusions4.3 Apsheron - Lower Kura Area4.3.1 Introduction4.3.2 Geochemical Characteristics4.3.3 Conclusions

5. REGIONAL GEOCHEMICAL CORRELATION OF OILS

5.1 Conventional Geochemical Interpretation in the Geological Context5.2 Statistical Treatment of the Data

6. CONCLUSIONS

7. REFERENCES

TABLES

2.1 Summary Listing of Oils Analysed in the Azerbaijan Kura Basin Oilbank Study3.1 Major Oil Fields of Azerbaijan in 19913.2 Reported Oil and Gas Production in Azerbaijan from 1930 to 19933.3 Historical Drilling Statistics for Azerbaijan3.4 Average Organic Carbon Contents for Sediments in Azerbaijan4.1 Physical Properties and Fractionation Data4.2 Carbon Isotope Data and Terpane Biomarker Ratios4.3 Sterane Biomarker Ratios5.1 Relative Contributions of Variables to Principal Components

APPENDICES

1. List of Abbreviations
2. Analytical Procedures and Techniques
3. Index of Alkane and Aromatic Molecular Biomarker GC-MS Peak Assignments and Interpretational Guidelines

ENCLOSURES

1. Hydrocarbon Occurrences and Principal Hydrocarbon Provinces
2. Basement Structure Map
3. Contour Map of Top Mesozoic Sediments and Top of Middle Pliocene Productive Series
4. Summary of Oil Correlation and Provenance

Volume 2: AnalyticalData

1. INTRODUCTION

1.1 Data Presentation1.2 Notes to Accompany Data Tables

2. ANALYTICAL DATA FOR KURA-IORI INTERFLUVE AND PREDMALOKAUSIS DEPRESSION OILS

2.1 Demir Tepe Udabno-72.2 West Gyurzundag-12.3 Palantekian-22.4 Tars Dallier-12.5 Naftalan

3. ANALYTICAL DATA FOR TALISH VANDAMSKIY ARCH OILS

3.1 Zardob-73.2 Shaftakhal-2503.3 Muradhanli-273.4 Muradhanli-373.5 Muradhanli-2323.6 Muradhanli-2463.7 Dzhafarly-21

4. ANALYTICAL DATA FOR SHEMAKHINO KOBUSTANSKIY DEPRESSION OILS

4.1 Dzhengi Mud Volcano4.2 Adjively-124.3 Umbaki-1144.4 Umbaki-1354.5 Kergez-2634.6 Gezdek-2104.7 Karadag-14.8 Kianizadag-294.9 Dashgil-154.10 Duvanny More-3204.11 Sangachaly More4.12 Astrakhanka-1

5. ANALYTICAL DATA FOR APSHERONSKIY DEPRESSION OILS

5.1 Binagady-11675.2 Romany-33125.3 Buzovny-145.4 Buzovny-10575.5 Surahany-9455.6 Surahany-16185.7 Gousany-17015.8 Karachuhur-645.9 Zykh-3145.10 Bibi-Eibat-25665.11 Peschany More-35.12 Peschany More-3485.13 Bahar-1485.14 Bahar-182

6. ANALYTICAL DATA FOR APSHERONO PREBALKHANSKIY ANTICLINE OILS

6.1 Banka Apsheronsky-46.2 Artem-6546.3 Octiabrskaya Revolutsia-36.4 Yuzhnoe-576.5 Neftiany Kamni-3036.6 Neftiany Kamni-20016.7 28 April-166.8 28 April-1896.9 Kaverochkina-2606.10 26 Bakinski Komisarov-16.11 Nachishevanskyoe-224

7. ANALYTICAL DATA FOR NIZNIKURINSKIY DEPRESSION OILS

7.1 Kalamadin-1617.2 Malyi Kharami-37.3 Kyurovdag-247.4 Kyurovdag-8897.5 Kyurovdag-9587.6 Kyursanglia North-4017.7 Kyursanglia South-47.8 Pirsagat-217.9 Pirsagat-857.10 Garasu-1227.11 Hilli-157.12 Hilli-4187.13 Hilli-4237.14 Neftechala-7097.15 Neftechala-1083

APPENDICES

1. List of Abbreviations
2. Analytical Procedures and Techniques
3. Index of Alkane and Aromatic Molecular Biomarker GC-MS Peak Assignments and Interpretational Guidelines