The Fry In Situ Combustion Project Performance And Economic Status

Abstract

Abstract A dry forward in situ combustion pilot was initiated in October, 1961, by Marathon Oil Company. This operation, known as the Fry Project, is developed in the Robinson sandstone, located in the Robinson Field, Crawford County, Illinois. The Robinson Sand is of Lower Pennsylvanian age and is believed to have been formed by stream deposition along a series of migrating point bars. The Fry reservoir, which trends from southwest to northeast, ranges in thickness from 0 to 55 feet (0–16.8 m). Oil viscosity ranges from 10 to 80 cp (.01-.08 Pas) across the trend. The sandstone has an average porosity of 19.7% and an average permeability of 320 md in the project area. Since initiation in 1961, the Project has been expanded to the present 517 (2092 × 10(3) m) productive acres and 3 active burn zones. Project production peaked in 1968 at 380 BOPD (60.4 m3/a) and is now peaked in 1968 at 380 BOPD (60.4 m3/a) and is now averaging 100 BOPD (15.9 m3/d) from 34 active wells. Cumulative production through 1977 is 1,056,167 BO (167,917 m3) from an estimated burned volume of 1,898 acre-feet (2,341,162 m3). Improved economics for a project of this type have occurred over the past five years as a result of increased stripper oil prices. A theoretical recovery was calculated using an in situ combustion correlation recently developed by Satman, Soliman, and Brigham. Comparison of the theoretical and actual recoveries indicates that the model is appropriate for the project. Comparison of project parameters with various screening criteria indicates that the criteria may be more limiting than necessary. Project operations have shown that in situ combustion can be an effective tool in recovering crude oil of lower viscosity (10–80 cp (.01-.08 Pas)) than normally associated with the combustion process. The success of this project clearly demonstrates the technical and economic feasibility of recovering significant reserves from an area that cannot be successfully waterflooded. Introduction The Fry In Situ Combustion Project in Crawford County, Illinois, was initiated in 1961 as a 3.3-acre (13.4 × 10(3) m) pilot test. Since that time the project has been expanded to three burn zones. The project has been expanded to three burn zones. The project has demonstrated the technical applicability project has demonstrated the technical applicability of in situ combustion and current economic calculations indicate the process is competitive with other investment alternatives. Detailed reservoir, geology and operational histories of this project have been previously reported. The purpose of this paper is to summarize past history, to compare performance with a recovery past history, to compare performance with a recovery correlation and screening criteria, and to discuss the general profitability of the in situ combustion process. process. RESERVOIR Reservoir Characteristics and Data The Fry reservoir is located in a lenticular body of Robinson sandstone of Lower Pennsylvanian age. This particular sand body is about 12,000 feet (3,658 m) long and 3,500 feet (1,067 m) wide; it varies in thickness from 0 to 55 feet (0 to 16.8 m), and trends from northeast to southwest at depths ranging from 880 to 936 feet (268 to 285 m). The reservoir is believed to have been formed by stream deposition along a series of migrating point bars. The reservoir sand is usually fine to point bars. The reservoir sand is usually fine to medium grained with quartz, feldspar and muscovite as the predominant minerals. The sand in the reservoir is composed of four distinct zones locally known as the A, B, C, and M.