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Documentation and Evaluation of the Dri l l ing and Production Stages in the Prinos Field, Off-shore Kavala, Greece

Prepared by George Koletsis

Athens, Greece

August, 2013

NATIONAL TECHNICAL UNIVERSITY OF ATHENSSCHOOL OF MINING & METALLURGICAL ENGINEERING

Documentation and Evaluation of the Dri l l ing and Production Stages in the Prinos Field, Offshore Kavala, Greece

Prepared by: George Koletsis 8th Semester (Id. Number: 07109052)

Company: Energean Oil & Gas

Supervisor Engineer: Christos Tomos, Senior Reservoir Engineer

Supervisor of Studentship: Sofia Stamataki, Professor National Technical University of Athens School of Mining and Metallurgical Engineering Department of Geological Sciences

Athens, GreeceAugust, 2013

NATIONAL TECHNICAL UNIVERSITY OF ATHENSSCHOOL OF MINING & METALLURGICAL ENGINEERING

Foreword

This report was written for Energean Oil & Gas by the undergraduate student George Koletsis (National Techni-cal University of Athens, School of Mining and Metallur-gical Engineering) as a project during his spring season studentship.

The purpose of this report is to provide information about the failures in drilling and production stages in the Prinos field, offshore Kavala. The data of this report was provided by Energean and include previous summaries and interpretations. Some well data is missing therefore a few information is missing. All interpretations and con-clusions presented herein are based on inferences from geological and drilling operations data.

I believe that the result is successful through the good will and my personal contributions. Also, I would like to especially thank my supervisor engineer Christos Tomos for guiding me right form the inception till the successful completion of the project. Next, I need to thank Costan-tinos Tzimeas, Paschalia Kiomourtzi, Halina Dana and Ivan Obetzanov for their help and cooperation through-out my studentship.

Last but not least, i would like to thank my partner of this project, Irma Panou-Filandra (University of Patras, De-partment of Geology) for her valuable assistance to some fields in her specialty.

Company Name

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Table of Contents

About Energean! 3

1.1 Corporate Overview! 3

Geological Status of Prinos-Kavala Basin! 5

2.1 Formation Analysis! 5

2.2 Sedimentary Analysis! 6

Hydrocarbon Reservoirs in Prinos-Kavala Basin! 7

3.1 Prinos Oil Field! 7

Well Data of Prinos Field! 8

4.1 Platform Alpha! 10

4.1.1 PA-2 (Prinos Alpha 2 – G6) 11

4.1.2 PA-9, 9A, 9B, 9C & PA-30 12

4.2 Platform Beta! 15

4.2.1 PB-17 (Prinos Beta 17 – G16) 15

4.2.2 PB-21 (Prinos Beta 21-G23) 17

4.2.3 PB-25 (Prinos Beta 25) 19

4.2.4 PB-27 (Prinos Beta 27) 21

4.3 Well Data Summary of Platforms Alpha and Beta! 22

Course of Action to Prevent Drilling and Production Failures! 24

5.1 Water Control! 24

5.2 Lost Circulation! 25

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5.3 Casing Collapse! 26

5.4 Key seat! 27

Drilling Fluids! 28

6.1 Basic Functions of a Drilling Fluid! 28

6.2 Types of Drilling Fluid! 28

6.2.1 Water-based Mud 29

6.2.2 Oil-based Mud 30

6.2.3 Synthetic-based Mud 30

6.2.4 Pneumatic Drilling Fluids 31

Appendix I - Definitions! 32

Appendix II - Images! 34

Bibliography! 38

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