Automation-Several Big Horn Basin Fields Monitored From One Point
Authors: Walsh John K. 
Published: December 2007

This paper presents a new mode of operations for monitoring and controlling five oil fields in Wyoming- the largest fully automated telemetering system of this type in the history of the petroleum industry. This is an integrated automated program which monitors or controls through a telemetering system, lease automatic custody transfer (LACT) units, automatic well test units, flow/ no-flow sensors for the individual wells, and lease alarm units. The paper reviews the general field automation program and discusses the components of the telemetering system.

Introduction

The five fields in Wyoming included in the field automation and telemetering system are the 92-well Frannie field and the 14-well South Elk Basin Tensleep unit, both north of Powell; the 23-well Bonanza field near Worland; the 39-well Gebo field near Thermopolis; and the 84-well Circle Ridge field west of Riverton. The five fields are within a radius of 60 miles and range from 50 to 100 miles apart. Total production of the five fields is currently 12,000 BOPD.The field automation program is divided into four systems:

LACT units; AWT units; monitoring systems for determining whether a well is producing (which in this paper are referred to as flow/no-flow systems); and general lease alarm systems.

The operation of the fields is monitored and controlled by telemetering through a programmable central facility located in the district production office at Billings, Mont. The Billings district telemetering system consists of two major components- the programmable central facility, which is actually an on-line computer similar to those used in manufacturing facilities, and the remote field installation called the satellite. Both components are designed around transistorized solid-state circuitry. The two major components are linked together by a conventional telegraph- grade 0–15 cycle line. The pilot installation of automation and telemetering, including the monitoring and controlling of automatic well testing, the shipping of oil through LACT units, the reporting of individual well flow conditions and lease alarms, has been operating successfully in Gebo since June, 1962, and demonstrated the reliability of the system. The system was expanded to include the Frannie, South Elk Basin, Circle Ridge and Bonanza fields in Aug, 1963.

Field Automation Systems

The field automation program varies from field to field. Each field has individual LACT units and a general lease alarm system, but not all fields are equipped with automatic well test units or flow/no-flow sensors. Gebo, the pilot area, is equipped with all four systems. In this field, production is from the Tensleep and Embar reservoirs. Although the Gebo field is a unit, production from each reservoir is segregated and has its own treating system, LACT unit, automatic well test unit, general lease alarm system and flow/no-flow system.

The LACT unit for each reservoir consists of one positive displacement meter, BS and W monitor, sampler and recirculating pump. Each system has its own bad oil tank.

Production in this field is moved from the well through individual flow lines to headers at the battery location. The headers are eight-way electrically operated selector valves capable of handling the flow lines of seven wells. The header is designed so that production is normally routed through a common flow line to the lease treating unit, but one well at a time can be routed to its particular test treater. The system has a test treater for the Embar and one for the Tensleep production. Each test treater is equipped with PD oil and water meters. Each well is equipped with a mechanical flow/no-flow sensor located at the header. All pump units are equipped with vibration detectors for shutting down the pumping unit when a malfunction of the unit or down-hole equipment occurs.

JPT

P. 983ˆ