Key Design Parameter of a Computer Production Control System
Authors: Burrell George R. 
Published: March 2010

Humble Oil & Refining Company is implementing a company-wide automation program that will ultimately include about 9,000 wells and 80 per cent of the company's reserves. Four computer-driven systems located in Division operating offices are involved in the implementation effort. Key design parameters for the computer systems are (1) identical computer hardware and software systems are applied at the Division operating level; (2) system information is a single data source for operations, engineering and accounting functions; and (3) field operating personnel control the system. These four Division systems are currently monitoring performance of 4,000 wells in 22 fields.

INTRODUCTION

HUMBLE OIL & REFINING COMPANY has installed identical Computer Production Control (CPC) systems in four Division offices. As shown in Figure I, these offices are located in Houston, Midland and Corpus Christi, Texas, and in New Orleans, Louisiana. A fifth system in the Headquarter's office in Houston is used for program development and for backup of Division systems. These s3fstems are currently monitoring the performance of 4,000 wells in 22 fields. Completion of the program in 1973 will include nearly 9,000 wells and 80 per cent of the Company's reserves. Total project cost will be approximately $50 million.

The automation project was initiated in early 1967 following a study that indicated (1) that technology was available to construct a reliable system and (2) that an attractive return on the required investment could be expected. A system designed for companywide application was recommended to minimize development costs and to streamline this effort. Due to expected system loading, communication circuit costs and established organizational structure, separate but identical computer-driven systems were recommended for installation at the company's Division operating level.

SYSTEM DESCRIPTION

Humble's CPC systems are driven by general-purpose process control computers having 32,768 16-hit words of core (at time of writing). Disk drives provide an additional 7,5 million words of random access storage. Computer peripheral equipment includes a line printer, card read/punch, keyboard/printer and one or two additional printers (typewriters), The computer systems are scheduled to have an additional 16,384 words of core installed in 1971.

The computer is connected to a supervisory control system (see Figure 2) with a Computer Interface Unit (CIU) to provide remote data acquisition and control function capability. A data channel is used for high-speed data transfer between the computer and CIU. The CIU will drive 16 communication circuits simultaneously in the maximum Division configuration.

Automation equipment in the field at the wells, metering sites, "and central facilities generates volume information, status and alarm data, and provides control capability. These end devices are connected to Remote Terminal Units (RTU) at central points within the field by individual wire pairs. The RTU stores the information generated by the end devices and) on request from the computer/CIU, sends the information to the computer center. As many as 10 RTU's can be connected to each of the communication circuits serviced by the CIU at the computer center.