An experimental study of crude oil recovery by high pressure nitrogen injection.

Abstract

The results of this experimental investigation showed the compositional distribution of the vapor phase throughout the core during the nitrogen injection process. The mechanism of the nitrogen displacement process was analyzed and the fronts formed during the oil recovery experiments were recorded and studied in order to better understand the overall recovery mechanism. The experiments were conducted in a low permeability, consolidated, sand-packed, stainless steel tube 125 feet long and 0.45 inches in diameter. Five sampling points were located at equal intervals along the length of the linear core. Vapor samples were collected periodically from the sampling valves and analyzed by the gas chromatograph. The objectives of this study were to investigate the: (1) Compositional changes taking place during the displacing of crude oil by continuous high pressure nitrogen injection. (2) Changes in the properties of the liquid and vapor phases. (3) Miscible pressures for nitrogen displacement. (4) Distance from the injection point at which the miscibility will be achieved.