Decommissioning Challenges in Thailand

Tularak, Ajj (Chevron Thailand E&P Ltd) | Khan, Waqar Ali (Chevron Thailand E&P Ltd) | Thungsuntonkhun, Witsarut

OnePetro 

Abstract
Thailand's oil and gas industry has been successful in finding and recovering hydrocarbon reserves in the Gulf of Thailand since last three decades and have currently installed over 200 fixed offshore structures. Some of these installations are now reaching the end of their economic productive lives and will need to be decommissioned soon. There are complex issues in terms of legislation, environment, safety, costs, technical feasibility and public acceptability. This paper describes the issues relevant to decommissioning in Thailand and proposes appropriate decommissioning solutions developed over the past few years.

The proposed decommissioning solutions are intended to support Thailand's oil and gas industry and its regulators in ensuring compliance with international decommissioning guidelines, balancing economics, safety, practicality and technical feasibility of operations with the environmental benefits and also satisfying needs of the key decommissioning stakeholders in Thailand so as to achieve conflict-free process of decommissioning.

Technical aspects of offshore removal process primarily relates to the lifting of modules and sub-sea structural cutting methods. Lifting techniques range from conventional crane barges used in installation to specialized decommissioning vessels. Basically cost, technical feasibility and safety are major drivers in selection of appropriate lifting method. Sub-sea cutting include explosives and cold cutting techniques, for which cost and environment are the major decision making factors. Environmental aspects of decommissioning can be categorized into short term and long term. Short term environmental impacts are primarily related to the decommissioning methodology whereas the long term environmental impacts are related to the chosen disposal scenario i.e., final destination of each component of an offshore facility. Key recommendations regarding environmental solutions are in the form of Best Practicable Environmental Option (BPEO) framework, which helps determining balanced disposal scenario as well as suitable decommissioning methodology.
Increased energy demands have currently resulted in rapid growth of number of offshore installations in the Gulf of Thailand. At the same time, the old disused installations need to be timely and appropriately decommissioned, which is not possible without having acceptable decommissioning solutions in hand. Such solutions need to be in compliance with applicable international decommissioning guidelines while adopting best practical environmental option hence assuring conflict-free decommissioning process. Therefore, development of such decommissioning solution are significant in assuring "RESPONSIBLE PERFORMANCE: TO DO THE BEST WE CAN" in order to help attain sustainable benefits for further development of Thailand's oil and gas industry.

Introduction
The Petroleum industry has brought enormous benefits to society. Petroleum reserves located under the seabed have resulted in the development of offshore structures (facilities) throughout the world. At the end of their economic production lives, these installations are required to be decommissioned to ensure safety of navigation and to protect the rights of other users of the sea. Offshore facilities decommissioning raises many complex issues in terms of environment, safety, technology and economics.

The industry has tried to develop and implement decommissioning strategies such that these issues are balanced. After 1995 the issue of decommissioning received global media attention with the successful disruption of plans to decommission the Brent Spar in the North Sea. This indicates the level of public interest and concern for the environment. The issue of public acceptability is therefore considered as an important factor in preparing decommissioning strategies. Currently, Thailand's oil and gas industry must face this challenge as some of the offshore installations in the Gulf of Thailand are reaching the end of their economic production lives.

Thailand oil and gas industry has been established for over 25 years and has been successful in finding and developing the natural resources that have helped the economic and social development of the Kingdom. Presently there are over two hundred fixed installations in the Gulf of Thailand and some of them are reaching the end of their economic production lives. The regulators are seriously taking up measures in order to develop guidelines that can ensure a balanced approach for decommissioning in terms of technical, environmental, legal and financial aspects of decommissioning. Thailand has previously encountered conflict situations in infrastructure projects and moreover, international disputes on decommissioning have emphasized the need of considering public opinion properly to avoid any conflict in decommissioning projects. Thailand industry regulators have a clear message to incorporate the public opinion into the decommissioning process. Therefore, efforts have been initiated for the development of decommissioning guidelines that can include the requirements of the stakeholders in order to avoid any subsequent conflicts in the oil and gas facilities decommissioning projects.