Research On The Control System For DCS-based Oilfield Central Processing Station

Central processing station for core equipment applied in oilfield crude oil processing is also known as oil-gas central processing multipurpose station for short. Central processing station system is composed by five parts including crude oil processing, natural gas pressurization and dehydration, sewage treatment, rinsing water-injection, fire control and crude oil stabilization.After being processed by dehydration and degassing and other treatments in central processing station, crude oil will turn into qualified commercial oil ready for exportation.Taking Supcon’s JX300X DCS as the research object which is stable in performance and simple in operation, this paper is intended to set up a comprehensive control system for central processing station, integrating crude oil dehydration, sewage treatment, rinsing water-injection, fire control and crude oil stabilization together with alarm logs as well as real-time and historic curvesgenerated for crucial parameters at the same time. Adopting the typical "three station and one line" mechanism in hardware structure, this control system is made up of operation station, engineer station, field control station and SCnet Ⅱ process control network, which is capable of satisfying the demands of automation, modernization and real-time management from systems such as the central processing station in the course of oil gas gathering and transportation.The final establishment of central processing station needs to go through three stages, which are hardware selection, software configuration development and system debugging as well as optimization.Moreover, by utilizing field control station, it will collect signals from the onsite instruments; and by making use of engineer station and operator station, it will create user interface program to monitor and control onsite devices; besides,by exploiting excessive SBUS-S2bus, it twill connect all the onsite hardware equipment of the control station together; in addition, by taking advantage of trunk network SCnet Ⅱ, it will achieve the data transmission and exchange between the stations. With above procedures, this system will ensure each stage and process of the central processing station to move on smoothly and accurate onsite data will be obtained and displayed. Furthermore, according to set value of the interlock, it will achieve control over the on-off status as well asthe valve opening degree of the equipment with alarming records, real time and historic curve for crucial parameters generated at the same time.