FACULTY OF SCIENCE AND TECHNOLOGY MASTER'S THESIS Study programme/specialisation: Marine and Offshore Technology Spring semester, 2019 Open Author: Kirill Obriashchenko Student number: 247461 (signature of author) Supervisors: Ove Tobias Gudmestad (UiS), Yuri Apollonevich Sazonov (Gubkin University) Title of master's thesis: FEASIBILITY STUDY OF THE AYASHKINSKOYE LICENSE BLOCK (SAKHALIN OFFSHORE) DEVELOPMENT Credits: 30 ECTS Keywords: Offshore Field Development, Sakhalin Island, Sea of Okhotsk, Ayashkinskoye license Number of pages: 92 block, Neptun, Triton, Gravity Based Structure, Subsea Production System, FEL analysis, CBA- + supplemental material/other: 10 analysis, feasibility study, ANSYS, GRP, Subsea protection, Dropped objects, Impact loads. Stavanger, June 15, 2019 1 Abstract Keywords: Offshore Field Development, Sakhalin Island, Sea of Okhotsk, Ayashkinskoye license block, Neptun, Triton, Gravity Based Structure, Subsea Production System, FEL analysis, CBA- analysis, feasibility study, ANSYS, GRP, Subsea protection, Dropped objects, Impact loads. Problem statement and objective Despite several successful existing offshore Russian projects such as Prirazlomnoye, Arkutun-Dagi, Piltun-Astokhskoye, Chayvo and Kirinskoye, Russian continental shelf remains to be a unique perspective for future exploration and development activities. In terms of recoverable reserves, Sakhalin offshore takes the second position in the chart of Russian Offshore Oil&Gas reserves. There are nine existing projects on the Russian shelf near the Sakhalin island. However, only three from the nine projects have reached the status of being developed. Hydrocarbon production on the island is carried out mainly under the Sakhalin-1, Sakhalin-2 and Sakhalin -3 projects. The Sakhalin -3 project appeals itself as one of the further developments since it has not been fully explored yet. The only successful project, put in operation, is Kirinskoye field. Nevertheless, there are other potentially perspective structures on the sites of Sakhalin-3. Among these is Ayashkinskoye license block which comprises several fields. The most perspective is Ayashkinskoye and Bautinskoye fields which have already been explored and received names Neptun and Triton respectively. The objective of the Master’s thesis is to come up with the possible solution of development of Ayashkinskoye license block. It is of great importance to narrow the criteria of choice to ensure the successful analysis to be performed as soon as all data would be available. The superior design of the development was based on: analysing the environmental conditions and present challenges of North-East Sakhalin Offshore; investigating all existed offshore development projects in that region; analysing the status of exploration development of Ayashkinskoye license block; Inspecting relevant development technologies, suitable for this license area; Calculation ice loads on columns of GBS platform; Modelling cases of impact loads from dropped objects. Scope of work First four chapters give the comprehensive report on present environmental conditions and associated challenges of Sakhalin Offshore. In the third chapter, the summary is provided on the existed field developments in that region. The fourth chapter is dedicated to the description of Ayashkinskoye license block. In chapter five, the potential field development scenario, based on FEL-analysis, is described. The study is aimed to cover the first three stages of such analysis due to the absence of data. The rough CBA- analysis, workflow chart and principal field layout are developed. The logical field development choice is performed. Possible loads on structures are calculated. The sixth chapter deals impact loads on protection subsea pipeline GRP covers. Six cases modelled in ANSYS workbench simulation software are presented. The seventh chapter shows several relevant technologies for the prevention of oil spill in the sensitive regions of Sakhalin offshore. 2 Acknowledgements I would like to express my deep attitude to both Universities: Gubkin and Stavanger University, respectively. I believe that only international cooperation in education and science would lead our society to a sustainable and safe future. A very special thanks need to be given to my supervisor, Professor Ove-Tobias Gudmestad, whose continuous help during these two years of studying deepened my knowledge in the related sphere. I appreciate his precious help and wise advises in writing this Master Thesis, which would not have been done without his lectures and helpful tips. I appreciate his concerns about our studying in Norway too. I am also very grateful to my supervisor from Gubkin University Professor Yuri Ap. Sazonov for his help and support and fresh point of view on some issues which have been touched in the scope of this work. I would like to highlight the significant contribution of the scientific supervisor of the Programme professor Anatoly B. Zolotukhin. His efforts to create such unique joint Programme and give a chance to students to broaden their knowledge, gain new experience and to understand this unique and fragile world are highly appreciated, I believe, by all alumni of this outstanding Programme. I would like to pass a sincere thanks to Professor Muk Chen Ong and PhD student Muhammad Ahmad Tauqeer for their support and coordination throughout the simulation part of this Thesis. In addition to this, I appreciate the University of Stavanger to provide workspace and powerful computer for the simulations. I also would like to thank PhD students Hui Cheng and Marek Jan Janocha for the help in working with ANSYS software and doing this project. The experience of studying on this Programme would not have been possible without the sponsorship from the company “Gazprom Neft Shelf”. I highly appreciate the help provided me to finish my Master’s Degree. Finally, the most important gratefulness goes to my family. Their support during all my education gave me a will to and courage to enter, study and finish my education. 3 Contents Abstract ........................................................................................................................................................ 2 Acknowledgements ...................................................................................................................................... 3 List of Figures .............................................................................................................................................. 6 List of tables ................................................................................................................................................. 8 List of abbreviations ................................................................................................................................... 9 Introduction ............................................................................................................................................... 10 1. Environmental conditions of the Okhotsk Sea on the Sakhalin island shelf ................................ 13 1.1. Geography and resources of the Sakhalin region ................................................................... 13 1.2. Geography of Okhotsk Sea ....................................................................................................... 14 1.3. Weather conditions ................................................................................................................... 15 1.3.1. Air temperature ................................................................................................................. 15 1.3.2. Air moisture ....................................................................................................................... 16 1.3.3. Wind conditions ................................................................................................................. 17 1.4. Hydrological conditions ............................................................................................................ 18 1.4.1. Wave conditions ................................................................................................................. 19 1.4.2. Currents ............................................................................................................................. 19 1.5. Soil conditions of area near the Chayvo Bay .......................................................................... 21 1.6. Tsunami occurrence .................................................................................................................. 22 1.7. Ice conditions ............................................................................................................................. 22 2. Present challenges of Sakhalin Offshore ............................................................................................. 25 2.1. Snowstorms ..................................................................................................................................... 25 2.2. Fog ................................................................................................................................................... 25 2.3. Thunders and glazed rains ............................................................................................................ 26 2.4. Atmospheric and sea spray icing .................................................................................................. 26 3. Existing Field