The structure of the master gas system--a system of gasgathering facilities and pipelines that collect associated gas as a by-product of oil and nonassociated gas--reflected both its original design and changes made during the latter half of the 1980s. At first it was anticipated that the master gas system would distribute and process gas produced in association with crude oil. However, declining crude oil output in the mid-1980s forced Saudi Aramco to supplement the system's gas feed by developing the kingdom's nonassociated gas resources. The current structure of the master gas system consists of sixty GOSPs in Khurays, As Saffaniyah, Al Ghawar, and Az Zuluf fields three gas-processing plants located at Al Barri, Shadqam, and Al Uthmaniyah the east-west natural gas liquids (NGL) pipeline that feeds NGL from Shadqam to Yanbu and two gas fraction plants at Yanbu and Al Juaymah. Saudi Aramco also added about 57 million cubic meters per day of nonassociated gas-gathering capacity to the master gas system. Furthermore, it installed facilities capable of producing up to almost 13 million cubic meters per day from the Abqaiq gas cap to meet peak demand, and 1.7 million cubic meters per day from the Qatif storage reservoir for emergency use. The system had the capacity to gather about 170 million cubic meters per day of unprocessed gas.

In 1992 the master gas system could produce about 600,000 bpd of NGL when operating at full capacity, which included 315,000 bpd of propane, 165,000 bpd of butane, and 120,000 bpd of natural gas. Saudi Arabia's refineries contributed another 40,000 bpd of liquid petroleum gas (LPG - propane and butane). The kingdom was the world's largest LPG exporter with a 30 percent market share of world seaborne trade in LPG.

Despite the impressive capabilities of the system, it had several shortcomings. The system lacked sufficient associated gas-gathering facilities as a result, substantial amounts of gas were flared or used in reinjection. Furthermore, there were insufficient processing plants once the gas was collected. Therefore, only about 113 million cubic meters per day of a total of nearly 170 million cubic meters per day of raw gas was processed. Finally, the government's domestic pricing policy, whereby gas was available to customers at US$0.50 per million British thermal units, yielded insufficient revenues to finance further gas-processing facilities.

Data as of December 1992