Performance of Peoria Field - Discovery to Unitization
Authors: Hegglund Martin O. 
Published: December 2007

This paper was prepared for the Rocky Mountain Regional Meeting of the Society of Petroleum Engineers of AIME, to be held in Casper, Wyoming, May 15–16, 1973. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon requested to the Editor PETROLEUM ENGINEERS JOURNAL is usually granted upon requested to the Editor of the appropriate journal, provided agreement to give proper credit is made.
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Abstract
The Peoria Muddy (J) Sand Unit, Arapahoe County, Colorado, is an excellent example of cooperation, conservation, and timely planning. With field discovery being July 19, planning. With field discovery being July 19, 1970, a full scale gas processing plant was in operation within eight months. Field development was completed in December, 1971, and unit operations began December 1, 1972, 28-1/2 months after date of field discovery. Cumulative oil production through 1972 is 5.54 million barrels, or 14.6% of the original oil in place. Facilities have been designed to inject up to 25,000 barrels of water per day; a contract has been signed for a remote supply of water; and construction of both supply and injection facilities began in February, 1973. Full scale injection of water should start in the spring of 1973. With unitization, gas cap production has been eliminated and wells with excessive gas-oil ratio are being shut in. Beneficial results are already demonstrated.
Peoria was the first significant oil discovery in the south portion of the Denver-Julesburg Basin in an area under heavy control by the Union Pacific Railroad. The success of Peoria at 6600' depth, versus 5000'-5500' for the majority of previous Muddy Sand field to the east and north, tended to accelerate exploration toward the still deeper portion of the basin westward toward Denver. Peoria has reservoir and fluid characteristics that are unique relative to shallower and nearly depleted "J" Sand reservoirs to the northeast. Peoria sand is of lower porosity, but its oil has a relatively high shrinkage factor and solution gas content. Geological conditions are complex, as evidenced by three distinct gas caps having different levels of gas-oil contact, by two distinct water-oil contacts having different subsea positions, and by the more important hydrocarbon deposition being in well developed channel sands, but, in some cases, extending into less important channel, and possibly bar sand deposits.

Introduction
Peoria Field is located in Arapahoe County, Colorado, approximately 40 miles east of Denver. Interstate 70 and the Union Pacific Railroad pass through the north Pacific Railroad pass through the north portion of the field. portion of the field.