In the oil and natural gas (O&G) industry, water is an essential element. It exists across various supply chain sectors within the industry under study. The sectors include drilling operations, followed by production processes, which involve injecting fluid into the reservoir to maintain pressure, disposing of the water generated from the reservoir, utilizing it in cooling towers, and using it for drinking and sanitary purposes. Thus, it is crucial to understand the water issue in these sectors and examine it within the context of a circular economy (CE) for transitioning strategies based on CE towards the oil and gas (O&G) industry. In this regard, this chapter aims to assess the plan based on the circular water economy (CWE) in the oil and gas (O&G) energy sector using the strengths, weaknesses, opportunities, and threats (SWOT) analytical technique. The key SWOT of CWE policies is identified. Then, the strategies based on CWE concepts are determined and ranked to promote the development of sustainable water resource management in the various sectors of the studied industry. To rank these strategies, a robust decision support system (DSS) has been developed under conditions of deep uncertainty. It can assist in implementing them effectively for stakeholders and decision-makers. The DSS integrates the combined compromise solution (CoCoSo) method and fuzzy set theory for achieving the aim of this work. Iran’s oil and gas energy system is considered the case study for the present work. The DSS of this chapter is a generic framework that can also be employed to analyze these strategies in other energy systems.