Evaluating offshore technologies for produced water management using GreenPro-I - a risk-based life cycle analysis for green and clean process selection and design

Sustainable development and environmental protection require green products, processes, and waste management strategies. The selection and design of green and clean processes and products involve handling a huge set of data related to the environment, economics and technologies. Therefore, it is essential to employ a comprehensive technique to guide decision-making under uncertainty that can incorporate these factors. The paper presents decision-making under uncertainty based on life cycle analysis and considering environmental, technological, and economical drivers in the analysis. The methodology, GreenPro-1, is applicable at any stage of a process design and can be used to evaluate the environmental burdens of a product or a process throughout its life cycle, and to identify and assess opportunities to make improvements. A weighting scheme is used to integrate various criteria and policies so that a most appropriate alternative can be selected. The GreenPro-1 methodology is applied to a case study for offshore produced water management. In the first stage, fourteen best available technologies (BAT) for treatment of produced water are evaluated individually using cradle-to-gate life cycle analysis. In the second stage, seven treatment strategies are developed from BAT and are further investigated. A treatment strategy that combines a hydrocyclone and produced water re-injection proved to be the best system among selected strategies. The combination of hydrocyclone and adsorption was found to be the next best treatment strategy. Two other noteworthy strategies were membrane and centrifuge combination, and down hole separation and injection.