Computer Control and Monitoring of Offshore Production

Abstract

Abstract This paper presents a new concept for supervisory control and monitoring of offshore gas-condensate production. The philosophy of the automation system's design, its attractive features, and operating experience gained to date are covered. Introduction The Lake Charles District of the CAGC Marine Region is predominantly a gas producing district operated by Continental Oil Co. for itself, producing district operated by Continental Oil Co. for itself, Atlantic-Richfield, Getty Oil Co., and Cities Service Oil Co. Gas discoveries and subsequent development in the East Cameron and West Cameron areas offshore from Cameron, Louisiana, now constitute a gas system consisting of 91 gas and gas-condensate wells located on 15 producing platforms. The gas system was put on production in 1958 after the platforms. The gas system was put on production in 1958 after the completion of a gas transmission line to the offshore platforms. Daily gas deliveries are averaging 350 MMcf along with 4,000 barrels of condensate per day. per day. The system has always been operated by personnel quartered in the field adjacent to one of the producing platforms. These operating personnel make daily trips by boat to their assigned platforms to check operations, change meter charts, pump inhibitor into the wells, and perform general maintenance duties. When personnel worked on a production platform, there was no communication with, or control of the producing variables. Process Description Process Description The producing equipment on each of the platforms in the Cameron Gas System is basically the same, differing only in capacity and brand. The attached isometric drawing of a typical platform layout, Exhibit I, shows the components of the producing equipment, their relative positions on the platform and the flow plan of the connecting piping. platform and the flow plan of the connecting piping. In general the functions that are performed on the platform are separation of water and condensate from the gas, dehydration of the gas by glycol absorption, and disposal of the free water. In addition to the production separator through which the commingled production from all of the wells flows, there is a test separator for determination of each individual well's flow rate and liquid production at least once each month. The well streams flow through individual flowlines into headers which are manifolded to facilitate flow either to the production separator or the test separator. The gas from the headers is expanded through adjustable chokes on the low temperature type separators, and separation of the free water and condensate is made. If it is necessary, the gas can be directed through a heating coil in the glycol reboiler to prevent freezing of the separator choke.