A framework for making maintenance decisions for oil and gas drilling and production equipment

Abstract There are few scientific maintenance decision-making methods in current maintenance and management of drilling and production equipment (DPE). Conventional methods have some conspicuous deficiencies and shortcomings, for example, unreasonable maintenance methods, surplus or insufficient maintenance, exorbitant maintenance costs and increasing failure frequency, which have caught a great influence to production safety and economic cost in the oil and gas exploitation process. In this study, a framework for making maintenance decisions was presented in order to improve the maintenance and management of the DPE. First, eight evaluation indexes and their scoring criteria were defined to quantify subjective evaluation of importance level of the DPE. Then, a linear weighted mathematical model was presented to calculate importance level value and a weight computing method of each evaluation index was put forward based on the Analytic Hierarchy Process (AHP). And the subjective effects were eliminated with Monte Carlo Simulation (MCS) in the scoring process. Next, maintenance decision-making trees (MDMTs) for the DPE were set up by reference to the logic decision tree of reliability-centred maintenance (RCM). Finally, feasibility of the framework was verified by testing a well control system in Tarim Oilfield. Therefore, the framework for making maintenance decisions can provide reasonable maintenance methods and achieve scientific maintenance and management for the DPE.