Joint reports


Cretaceous and Jurassic Potential Reservoir Facies of North Azerbaijan


  • The executive companies: GIA / UNOCAL
  • The year of publication: March 1999
  • Code: -
  • Volumes: total 2
    volumes with appendixes in same amount: 2



EXECUTIVE SUMMARY


This report was produced jointy by Unocal and Geology Institute of Azerbaijan, with a primary goal to describe potential reservoir facies in the Mesozoic section of northern Azerbaijan. The report consists of three volumes. Volume I detailes the geological and organic geochemical results derived from field work done at ten outcrop localities in the Greater Caucasus Mountains in northern Azerbaijan. Strata ranging from Middle Jurassic Aalenian to Upper Cretaceous Maastrichtian were examined and sampled. Volume II contains text and graphics provided by the Geology Institute, including important reservoir, tectonic, structural, stratigraphic, and biostratigraphic information. Biostratigraphy contractor reports (Appendices I, II and III) are also part of this volume. Volume III includes geochemistry and petrography contractor reports (Appendices IV, V, VI, and VII) generated from rocks samples collected at the outcrop localities and from oils by the Geology Institute.


Strata deposited in the Tethyan basin in northern Azerbaijan include a wide variety of facies and lithologies. Facies examined during the course of this project ranged from deep basinal shales to high-energy, shallow water, bioclastic and oolitic grainstone shales. Between these end members were carbonate and clastic turbidite and debris flows, shelf sands, talus deposits, reefs, and shallow lagoonal carbonates. Complicating the study of this strata are the narrow, northwest-southeast trending, structural zones formed as the Arabian Plate collided with the Eurasian Plate during the Late Tertiary, resulting in the Greater Caucasus Mountains. The Mesozoic strata of the Caucasus area has been intensily faulted and folded. Although complicating the reconstructions of paleoenvironments, the tectonics of the area did result in the exposure of excellent outcrops. Fossils used for stratigraphic correlation in this area include ammonites, corals, belemnites, gastropods, and brachiopods. Microfossils, such as foraminifera, calcareous nannofossils, and dinoflagellates, are also important, and these groups were utilized in the current study for age and paleoenvironmental information. Detailed biostratigraphic work has been undertaken in this region in the past by many Azeri geologists and is summarized in Volume II.


Potential reservoir facies are distributed throughout the mid-Jurassic to upper Cretaceous stratigraphic section of northern Azerbaijan. Promary zone of interest identified in this study include the Albian Kyulyuli sandstones and the reef and grainstone shoal carbonates deposited during Oxfordian and Tithonian time. However, other potantial reservoirs were identified and are discussed in this report.


Two sandstones that have potential as reservoir were sampled during fieldwork and are described in Volume I. The first, the Jimi Suite, was deposited during the upper Aalenina to lower Bajocian. In outcrop these litharenites have modest reservoir qualities. Clay and carbonate cements have significantly reduced the reservoir quality of these sands. Measured porosities range from 2.6% to 7.5%, and permeabilities are under 1.0 millidarcy. The second sandstone, the Kyulyuli sandstone, was deposited in the Albian. At the Altiagach outcrop the Kyulyulisands appear to have been deposited as shelf sands. The sandstone samples collected are classified as lithic arkoses to subarkoses. Measured porosities of the outcrop samples range from 5% to 17%, and permeabilites vary from 3.7 to 40.9 millidarcies. Other potential sandstones reservoirs in northern Azerbaijan are discussed in Volume IV.


Potenbtial carbonate reservoir facies described as part of this study include reefs and high energy shoals deposited in shelf or shallow carbonate platform environments. Reef forming organisms in the Tethyan seaway were diverse and inluded bracnching and massive corals, coralline algae, rudists, enchinoderms, mollusks, brachiopods and bryozoans. The reefs formed by these organisms generated a large amount of bioclastic debris that was reworked and deposited as bioclastic grainstone-packstone shoals. Shallow, high-energy carbonate platforms and shelf environments were also conductive to the formation of oolite shoals. Reef, or boundstone deposits were observed during the fieldwork at Beshbarmag, Charag, Galaalti, and Tengialti. Shallow water bioclastic or ooid grainstoine-packstone shoals were described at Gazma Griz, Galaalti, and Tengialti outcrops. While there was almost no preserved porosity in these facies in outcrop, they could be excellent potential reservoirs given a favourable diagenetic history. Other carbonate facies of interest observed during the fieldworkd include the channelized, deepwater grainstone and packstone in the Nardaran exposure and the hundreds of meters of thin, bioclastic grainstone-packstone turbidites interbedded with deepwater shales at Dibrar.


While the primary focus of this study was reservoir facies, geochemical analyses were run for twenty-five outcrop and twenty-one oil samples. Geochemical screening of the outcrop samples indicates that two rock samples have a TOC content greater than 1.00% . Only one sample, a Barremian-Albian age sample form the Kelevudag section with TOC of 3.16% , has the generative potentoal and Hydrogen Index sufficient to be a good potental source rock. The other sample, of Aptian (?) age from the Dibrar section with TOC of 2.54%, has a low generative potential and Hydrogen Index. The twenty-one oil samples were from the Amirkhanly, Saadan, Chandogar-Zorat, Siazan-Nardaran, Tekchai, Zagly, and Zeyva Fields. Based on the oil analyses, two "effective" source rock systems are present in the PriCaspian-Kuba area, an Oligocene-Miocene source system and an Upper Jurassic source system.


CONTENTS

VOLUME I

 

  • IN MEMORIAM
  • ABSTRACTS
  • LIST OF TEXT-FIGURES
  • LIST OF CHARTS AND TABLES
  • REPORT COVER DESCRIPTION
  • AKNOWLEDGEMENTS
  • INTRODUCTION


Study Objectives
Report Organization
Participating Geoscientists
Chronostratigraphic and Stratigraphic Units

 

  • OUTCROP STUDY


Sample Set Analyses

Petrographic Analyses
Micropaleontological Analyses
Organic Geochemical Analyses
Outcrop Localities


ALTIAGACH

LOWER ALTIAGACH SECTION
Description of Section
Sample Set
Petrographic Analyses
Micropaleontological Analyses
Organic Geochemical Analyses
UPPER ALTIAGACH SECTION
Description of Section
Sample Set
Petrographic Analyses
Micropaleontological Analyses
Organic Geochemical Analyses
GRAPHICS AND PHOTOGRAPHS
Outcrop Locality Map
Outcrop Measured Sections
Outcrop Photographs
Thin-section Photomicrographs


BESHBARMAG

Overview of Section
Sample Set
Petrographic Analyses
Micropaleontological Analyses
Paleoenvironmental Analyses
Organic Geochemical Analyses
GRAPHICS AND PHOTOGRAPHS
Outcrop Locality Map
Outcrop Measured Sections
Outcrop Photographs
Thin-section Photomicrographs


CHARAG

LOWER SECTION
Description of Section
Sample Set
Petrographic Analyses
Micropaleontological Analyses
Organic Geochemical Analyses
UPPER SECTION
Description of Section
Sample Set
Petrographic Analyses
Paleoenvironmental Interpretation
Micropaleontological Analyses
Organic Geochemical Analyses
GRAPHICS AND PHOTOGRAPHS
Outcrop Locality Map
Outcrop Measured Sections
Outcrop Photographs
Thin-section Photomicrographs


DIBRAR

APTIAN SECTION
Description of Section
Sample Set
Petrographic Analyses
Micropaleontological Analyses
Organic Geochemical Analyses
ALBIAN SECTION
Description of Section
Sample Set
Petrographic Analyses
Micropaleontological Analyses
Organic Geochemical Analyses
CENOMANIAN SECTION
Description of Section
Sample Set
Petrographic Analyses
Micropaleontological Analyses
Organic Geochemical Analyses
TURONIAN SECTION
Description of Section
Sample Set
Petrographic Analyses
Micropaleontological Analyses
Organic Geochemical Analyses
CONIACIAN SECTION
Description of Section
Sample Set
Petrographic Analyses
Micropaleontological Analyses
Organic Geochemical Analyses
SANTONIAN SECTION
Description of Section
Sample Set
Petrographic Analyses
Micropaleontological Analyses
Organic Geochemical Analyses
CAMPANIAN SECTION
Description of Section
Sample Set
Petrographic Analyses
Micropaleontological Analyses
Organic Geochemical Analyses
MAASTRICHTIAN SECTION
Description of Section
Sample Set
Petrographic Analyses
Micropaleontological Analyses
Organic Geochemical Analyses
GRAPHICS AND PHOTOGRAPHS
Outcrop Locality Map
Outcrop Measured Sections
Outcrop Photographs
Thin-section Photomicrographs


GAZMA GRIZ

GAZMA GRIZ SECTION
Description of Section
Sample Set
Petrographic Analyses
Paleoenvironmental Interpretation
Micropaleontological Analyses
Organic Geochemical Analyses
GAZMA GRIZ SECTION
Description of Section
Sample Set
Petrographic Analyses
Paleoenvironmental Interpretation
Micropaleontological Analyses
Organic Geochemical Analyses
GRAPHICS AND PHOTOGRAPHS
Outcrop Locality Map
Outcrop Measured Sections
Outcrop Photographs
Thin-section Photomicrographs


JIMICHAI

JURASSIC UPSTREAM SHALE SECTION
Description of Section
Sample Set
Petrographic Analyses
Micropaleontological Analyses
Organic Geochemical Analyses
JURASSIC SANDSTONE SECTION
Description of Section
Sample Set
Petrographic Analyses
Paleoenvironmental Interpretation
Micropaleontological Analyses
Organic Geochemical Analyses
LOWER CRETACEOUS SECTION
Description of Section
Sample Set
Petrographic Analyses
Paleoenvironmental Interpretation
Micropaleontological Analyses
Organic Geochemical Analyses
GRAPHICS AND PHOTOGRAPHS
Outcrop Locality Map
Outcrop Measured Sections
Outcrop Photographs
Thin-section Photomicrographs


KELEVUDAG

ROAD CUT SECTION
Description of Section
Sample Set
Petrographic Analyses
Micropaleontological Analyses
Organic Geochemical Analyses
VALLEY SECTION
Description of Section
Sample Set
Petrographic Analyses
Micropaleontological Analyses
MOUNTAIN SECTION
Overview of Section
Albian Section
Petrographic Analyses
Micropaleontological Analyses
Organic Geochemical Analyses
Cenomanian Section
Petrographic Analyses
Paleoenvironmental Interpretation
Micropaleontological Analyses
Organic Geochemical Analyses
Turonian Section
Petrographic Analyses
Paleoenvironmental Interpretation
Micropaleontological Analyses
Organic Geochemical Analyses
Coniacian Section
Petrographic Analyses
Paleoenvironmental Interpretation
Micropaleontological Analyses
GRAPHICS AND PHOTOGRAPHS
Outcrop Locality Map
Outcrop Measured Sections
Outcrop Photographs
Thin-section Photomicrographs


NARDARAN

Description of Section
Sample Set
Petrographic Analyses
Reservoir Quality
Paleoenvironmental Interpretation
Micropaleontological Analyses
Organic Geochemical Analyses
GRAPHICS AND PHOTOGRAPHS
Outcrop Locality Map
Outcrop Measured Sections
Outcrop Photographs
Thin-section Photomicrographs


SANATORIUM (GALAALTI)

Description of Section
Sample Set
Petrographic Analyses
Paleoenvironmental Interpretation
Micropaleontological Analyses
Organic Geochemical Analyses
GRAPHICS AND PHOTOGRAPHS
Outcrop Locality Map
Outcrop Measured Sections
Outcrop Photographs
Thin-section Photomicrographs


TENGIALTI

LOWER TENGIALTI SECTION
Description of Section
Sample Set
Petrographic Analyses
Micropaleontological Analyses
Organic Geochemical Analyses
UPPER TENGIALTI SECTION
Description of Section
Sample Set
Petrographic Analyses
Paleoenvironmental Interpretation
Micropaleontological Analyses
Organic Geochemical Analyses
GRAPHICS AND PHOTOGRAPHS
Outcrop Locality Map
Outcrop Measured Sections
Outcrop Photographs
Thin-section Photomicrographs


 

  • SELECTED OILS STUDY

Oils Sample Set
Study Objectives
Analyses and Interpretation
Conclusions


LIST OF TEXT-FIGURES
LIST OF CHARTS AND TABLES


VOLUME II

 

  • INTRODUCTION

  • CHAPTER 1: STRUCTURE AND TECTONIC HISTORY OF THE NORTHERN REGIONS OF AZERBAIJAN

  • CHAPTER 2: STRATIGRAPHY AND BIOSTRATIGRAPHY OF JURASSIC AND CRETACEOUS DEPOSITS OF NORTHERN AZERBAIJAN

  • CHAPTER 3: STRUCTURE AND DEPOSITION IN THE GREATER CAUCASUS AREA DURING THE JURASSIC AND CRETACEOUS

  • CHAPTER 4: POTENTIAL OIL AND GAS RESERVOIRS IN NORTHEAST AZERBAIJAN

  • REFERENCES CITED

LIST OF TEXT-FIGURES
LIST OF CHARTS
LIST OF TABLES
LIST OF TABLES (following Chapter 4)


  • REPORT APPENDICES

Appendix I: Geological evaluation of Cretaceous and Jurassic outcrop samples from the South Caspian Basin, Azerbaijan (Reservoirs, Inc., Houston, Texas)


Appendix II:
Palynology report of 325 field samples from the Caucasus Mts. (Robertson International Ltd, Llandudno, Wales)


Appendix III:
Palynological investigation of a collection of 25 outcrop samples from the Greater Caucasus Mts., Azerbaijan (British Geological Survey, London, England; Jin Riding)


VOLUME III


 

  • REPORT APPENDICES (Continued)

Appendix IV:
TOC, RockEval, and VR data for 25 South Caspian outcrop samples (APTI Geoscience Lab, Houston, Texas)


Appendix V:
Biomarker and related extraction data for one South Caspian outcrop sample (APTI Geoscience Lab, Houston, Texas)


Appendix VI:
Petroleum geochemistry of the PriCaspian-Kuba region, onshore northern Azerbaijan (G.Rinaldi, Unocal Technology Group)


Appendix VII:
Geochemical analyses of 22 Azeri oils (APTI Geoscience Lab, Houston, Texas)