Remote Gas Measurement for Production Allocation: Douglas Creek Arch Region, Colorado

Abstract

Abstract A Supervisory Control and Data Acquisition system has been installed as a part of natural gas production operations in Northwestern Colorado. production operations in Northwestern Colorado. The system was installed in conjunction with a large production acceleration project and assists in monitoring gas production from the individual well, through a gas gathering system and into a company owned processing facility. Advantages offered by the system include a comprehensive overview of gas production and gathering operations from a central location and improved efficiency by allowing production operators to target their daily activities toward problem areas. Introduction In 1988 an accelerated drilling and development program was initiated in the Douglas Creek Arch program was initiated in the Douglas Creek Arch Production area, T2-3S, R101-103W, Rio Blanco Production area, T2-3S, R101-103W, Rio Blanco County, Colorado, to tap potential gas reserves and to improve marketing opportunities in the region. The development project covers a geographic area of over 66 square miles (170 sq. km) and, upon completion in late 1990, will include approximately 220 new and existing gas producing wells. A major part of the project included installing a gas gathering system to deliver natural gas from the production wells to a company owned gas processing facility. Prior to the development processing facility. Prior to the development project, gas gathering and processing facilities project, gas gathering and processing facilities were owned and operated by the gas buyer. Regional terrain is very rugged with variations in elevation from 6200 ft. to 7380 ft. (1890 m to 2250 m). Seasonal temperature varies from -40 to over 100 deg. F (-40 to 37 deg. C). Narrow, winding lease roads, lack of utility power and seasonal weather conditions add to the difficulty of operating the lease. Due to the large number of wells, wide geographic area and rough terrain a method was sought to minimize the number of personnel that would need to be added to maintain and operate the new production wells and gathering system. One alternative to large increases in personnel was the installation of a Supervisory Control and Data Acquisition.(SCADA) system. The Douglas Creek Arch Telemetry system is a SCADA system consisting of solar powered remote terminal units (RTU's) at each gas well, UHF radio communications and a host computer located in the field production office. The gas turbine meters, used at each well for production allocation measurement, are considered part of the SCADA system. The RTU's monitor an "intelligent" gas turbine meter and an underground liquid trap at each well. The RTU then transmits the production and level information over UHF radio to a SCADA host computer. Another computer, located in the division office over 350 miles away, has access to the field SCADA host over standard telephone lines for data retrieval and maintenance tasks. An overview of the installed SCADA system and its components is shown in Figure 1. The total time from when the concept of using a SCADA system was discussed to the installation of the first RTU was less than nine months. Production allocation, based on data provided by the SCADA system, formally began in January 1989, approximately one year after the concept of a SCADA system was first introduced. P. 291