Concrete GBS LNG Solution for Shallow Arctic Regions

摘要

The Arctic is becoming increasingly important in securing energy supplies for the future, notwithstanding the economic, environmental and social challenge. Also, finding and extracting oil and gas in the Arctic and Subarctic regions is itself challenging due to extreme temperatures, ice conditions, remoteness and a sensitive natural environment. Liquefied Natural Gas (LNG) can be produced Onshore, Offshore (FLNG) and near shore. Onshore is the most common LNG solution, however in hostile Arctic environments and remote areas onshore construction becomes expensive and challenging. Likewise Offshore LNG (FLNG), considered for export of offshore gas reserves and normally produced from deep water subsea wells, is not yet considered feasible for hostile Arctic environments where pack ice is prevalent. The concrete Gravity Base Structure (GBS) LNG Solution can address the shortcomings of Onshore LNG and FLNG solutions and should be considered where: 1. Export of gas is proposed from remote areas and harsh (particularly Arctic) environments where onshore plants will be very expensive and time consuming to build 2. Local content is a key driver 3. There are environmentally sensitive areas and suitable, available land for an Onshore plant is difficult to find 4. Dredging is required over a long distance from shore to water deep enough for LNG carriers 5. There are expansions plans for LNG production plant This paper is based on a concept study[1] with an objective to develop an economically attractive Arctic concrete GBS based LNG solution that demonstrates the technical functionality of such a concept with regard to HSE, constructability, operability, maintainability and offloading availability for shallow Arctic regions. The study demonstrates that the GBS LNG Solution for Shallow Arctic Regions is feasible, both economically and technically, in a size commonly found for onshore projects. In addition the following are developed in more detail: 1. Definition of the HSE, constructability, operability, maintainability and offloading availability requirements 2. Outline of the typical Layout and Design considerations and solutions 3. Outline of the typical operational considerations 4. Outline of special design considerations that must be applied to an LNG plant to meet winterization, operations and maintenance, safety, Search and Rescue (SAR) and marine operations requirements The study presents a robust and feasible GBS LNG configuration. Solutions to operational issues, including a winterization strategy and loading/offloading, are developed.