Research On Condition Monitoring Technology Of Storage Tanks In Oilfield Combination Station And System Implementation

Storage tank is one of key equipments in oilfield combination station, the residual life prediction of corroded storage tanks can investigate the condition of storage tanks and guarantee the security of the combination station production effectively. This paper studies the methods of residual life prediction of corroded storage tanks and develops the oilfield combination station equipments maintenance data management system.The failure form and mechanism of the storage tanks are analyzed firstly. There are dome roof tanks and floating roof tanks in combination station. Corrosion perforation, instability and crack are the failure forms of the two types of storage tank. According to the analysis of the storage tank fault tree, corrosion is the most important reason for tank failures.Based on the characteristics of the corrosion parameters, the assessment to the tank floor, tank shell and tank roof is carried out. The corrosion type of tank floor is pitting, and statistic method is used to calculate the minimum remaining thickness and reliability of the tank floor. The corrosion type of tank shell is uniform corrosion, and the reliability of the tank shell is calculated in accordance with the stability checking method of the tank shell. The corrosion type of tank roof is localized corrosion, and the reliability of the tank roof is given by comparing the minimum remaining thickness and stability of the tank roof. Based on the assessment results of the tank floor, tank shell and tank roof, the AHP and fuzzy evaluation method is used in health assessment of the storage tank.The residual life prediction of corroded storage tanks includes the corrosion defects size trend prediction and corrosion rate trend prediction of storage tanks. There are many prediction methods based on time series, the grey theory model GM(1, 1) is one of the most common methods for the small sample data. Trend of corrosion rate and corrosion defects size of storage tanks can be predicted at any time with the improved grey theory model GM(1, 1).Orienting the application background of maintenance data management of the oilfield combination station equipments, software system requirement is analyzed, and the function model and the data model and the architecture of the system are designed in turn. Subsequently, based on the oilfield combination station storage tanks condition evaluation and residual life prediction techniques proposed, a oilfield combination station equipments maintenance data management system is developed.