Oil & gas block operatorship may change as the block's agreement contract changes. The changing executions expected to have smooth transition between current operator to the upcoming operator since it may interfere performance of safety, environment, health, efficiency, reliability, production, and workforce. Focusing in environmental issues, there are some steps that called ‘SAFE’, i.e. consist of Scoping, Assessment, Follow up action, and Ensure. ‘SAFE’ is risk-based liabilities approach that involve both operators (current & the upcoming) and may assisted by Government agency. Scoping is to define petroleum agreement requirement, the areas/locations, production facilities status, environmental related facilities, supporting facilities, environmental audit result, environmental performance, permitting & reporting requirements, allegation of contamination records, and enforcement documents. Scoping conducted by desktop documents review and field visit if necessary. Result of the scoping is more precise high-level list of concern items to focus on for further Assessment. On Assessment step, all identified concern items assessed further with methods, liability, Role & Responsibility, and budget to have more reliable and accurate of risk calculation (risk revalidation). Methods describe how to conduct the assessment such as workshop, coordination meeting, site visit, aerial photography analysis etc. Liability of selected item to understand whether closure of past and present liabilities have been performed and also mitigation for identified potential future liabilities have been secured to avoid future potential conflict of liability between operators. Liability cover of compliance, remediation, fines & penalties, compensation, punitive damages, and natural resource damages. Role & responsibility to define who does what and how on when and who is responsible for the closure actions. Budget to quantify the environmental risk. All the items under the Assessment step considered to perform risk revalidation. Result of the assessment (recommendation) then follow up by actions to mitigate the potential risk. It may need physical activities such as facilities decommissioning and clean up, further environmental study, government bureaucracy approval, agreement of environmental procedure sharing etc. Follow up action require regular tracking progress status in serial times. At the last step, ensure all identified high and medium risk mitigated as low as reasonably practicable (ALARP) remaining risk. Finally, conducting ‘SAFE’ thoroughly for all identified risks, both operators may have clear role & responsibility, focus utilizing the resources, compete with the deadline time, avoid dispute liabilities post the transition date, and ensure continuity of environmental compliance.