Gas Well Automation

Abstract

Abstract The design and operation of an automated gas flow and well control system is discussed. The system, designed to reduce operating costs and improve operating efficiency, presently controls 44 gas completions in the Bastion Bay field, Plaquemines Parish, in the marshes of South Louisiana. All wells are controlled from and connected with a central control station via buried multiconductor cable. The reasons remote control is desirable in this field are discussed, the design requirements are listed, the operation of the system is described and the advantages and disadvantages of the system selected are cited. Introduction There has been a recent growing tendency for oil companies to reduce or eliminate routine manual labor through the use of equipment designed to operate remotely, unattended and automatically. Systems are presently available for oil field use that can accomplish almost any desired function, limited only by the imagination of the engineer and the amount of investment a company wishes to make. It is the job of the engineer to selectively utilize systems that are practical in application and yet reasonable in cost. The primary function of any automation system is to increase operating efficiency and reduce operating costs. The object of this paper is to review the process by which automation equipment was selected for a large South Louisiana gas field, to describe the automation system selected and to outline its advantages and disadvantages. Description of Field Fig. 1 shows the geographical location of the Bastion Bay field, Plaquemines Parish, La. It is located in the Mississippi River delta area, approximately 70 miles southeast of New Orleans. Tenneco Oil Co., acting as operator for Tennessee Gas Transmission Co., operates 44 gas wells located within an area of approximately 8 sq miles. The field is located in a salt marsh adjacent to the Gulf of Mexico and is accessible only by boat. It is also approximately 12 miles from the nearest boat landing or supply point. All wells in the field were drilled from shallow-water, barge-mounted drilling rigs, and all wells are connected through a series of dredged access canals. Fig. 2 shows the field layout and location of the wells and canals. The water depth throughout the field is primarily dependent upon the tide, but ranges from 4 to 8 ft. In this field conservation units are formed about most of the wells, which result in varying working and royalty interests for each completion. Therefore, each gas completion produces through an individual heater and low temperature separation unit, and its production is separately metered. The condensate passes through individual positive volume meters and is then commingled into a condensate pipeline gathering system. JPT P. 873ˆ