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Impact of Offshore Disposal Solutions Executive Summary - Topic Area 7.2 Environmental Resources Management with AMBIOS Environmental Consultants Ltd This study is part of the research and development programme of the UKOOA Drill Cuttings Joint Industry Project and is concerned with the practicality of dealing offshore with recovered cutting piles. The study was greatly assisted through the creation of an informal research community comprising industry and academia in Europe and USA, suppliers of treatment and disposal techniques and the teams undertaking other studies for the UKOOA initiative. The main focus of this study was the identification and assessment of solids treatment techniques. The reason for this was that methods to store and handle retrieved materials, to separate solids and liquids and to treat oily water are routinely used in the North Sea. Currently, the only acceptable offshore technique for dealing with oily drill cuttings is reinjection into a suitable formation. However, there are a number of emerging technologies as well as established onshore techniques for cleaning cuttings with potential for offshore application. Onshore solids treatment techniques considered were grinding; direct thermal desorption; and indirect thermal desorption. Emerging solids treatment techniques considered were microemulsion; supercritical extraction using liquid natural gas; and supercritical extraction using liquid carbon dioxide. Seven options were compared using sixteen criteria to address engineering feasibility, performance, cost and environmental issues. Being the established technique for dealing with cuttings, reinjection scored reasonably against most criteria. However, where there is no suitable formation for reinjection, other options need to be considered. Transport of solids to shore for treatment compared favourably especially in terms of solid and water treatment rates and the potential for reuse of recovered oil and cleaned cuttings. However, onshore options are being considered in greater detail by another study in the research programme. Of the options for offshore solids treatment followed by discharge to sea, grinding and indirect thermal desorption systems scored well both being able to clean cuttings to less than 0.5% residual oil content and having potential for good energy efficiency especially when the energy value of recovered oil is taken into account. However, both these techniques have high deckspace and deck weight requirements and are probably best suited to vessel rather than topside installation. In addition, the operating and capital costs are currently high in comparison to the other options but there is potential for reducing these through greater system integration and further discussions with suppliers.