Electrification of Gas Well Production System Reduces Operational Costs in Saudi Aramco Gas Field

Abstract

AbstractA major Middle East operator has been producing gas from the same formation for approximately 20 years, using conventional hydraulic actuators to control wellhead gate valves. These actuators have been operated from a hydraulic control panel that is pneumatically powered, and the compressors used to generate the instrument air have been electrically driven. Although the actuators have been able to perform satisfactorily in controlling the wellhead gate valves, the operations have not been cost efficient for several reasons. First, the pneumatic/hydraulic control systems have been maintenance intensive. Secondly, electricity has been required to run air compressors to power the hydraulic actuators.Recently, the operator began a five-year drilling program to develop additional gas reserves, and as part of this process, decided to investigate alternatives to existing well-site equipment. One of the primary requirements of the new equipment was that it reduce operating costs. Areas targeted to provide the savings would be:The current levels of equipment maintenance and related manpower needs Equipment integrity against the environmental conditions inherent to the area (blowing sand, heat, rain, etc.) Environmental safety.This paper will discuss a first-of-its-kind all electric system using electric gate-valve actuators, an electric control panel with PLC logic controller as well as electric pressure pilots, electric fusible plugs, electric emergency shut-down (ESD) switches, and a battery back-up system that was developed for this installation.An existing well was converted to the system, and a rigorous one year testing program was carried out by the operator. In addition to normal exposure to the elements and routine opening and closing of the well to meet production demands, the test also included over 300 additional open and close cycles on each of the 3 electric actuators on the tree. After conducting the test program, the operator estimates that capital cost savings for the all electric system could be in excess of $200,000 per well over the present pneumatic/hydraulic systems. Additional savings in manpower and maintenance are also anticipated.