Open AccessTHE EFFECT OF THE CYCLICAL NITROGEN INJECTION ON THE FINAL COEFFICIENT OF GAS RECOVERY AT DIFFERENT RATES IN THE DEPLETED GAS RESERVOIR
Author(s) -
Р. М. Кондрат,
Л. І. Хайдарова
Publication year - 2018
Publication title -
rozvìdka ta rozrobka naftovih ì gazovih rodoviŝ
Language(s) - English
Resource type - Journals
eISSN - 2415-332X
pISSN - 1993-9973
DOI - 10.31471/1993-9973-2018-4(69)-15-22
Subject(s) - nitrogen , residual , petroleum engineering , chemistry , injection well , nitrogen gas , geology , organic chemistry , algorithm , computer science
The application of non-hydrocarbon gases with the aim of displacing residual gas from depleted fields is substantiated. Mathematical modeling is carried out of the process of residual gas displacing with nitrogen in the GEM compositional simulating module under the conditions of a hypothetical gas reservoir of circular shape. The said module is a part of the licensed CMG computer program. The effect of the cyclical nature of the aquifer injection nitrogen into depleted gas reservoir at different rates till the final gas recovery coefficient for residual gas is developed. The study concerns different durations of nitrogen injection cycles into the reservoir (6, 12, 18, 24, 30, and 36 months) and various correlations of the rates of nitrogen injection and gas production in reservoir conditions of 1:1; 1.5:1; 2:1. During the nitrogen injection into the reservoir, the output wells stopped; whereas after surcease of the nitrogen injection, they were again exploited until the reservoir pressure reached to 0.1 Pprimary. Then the process of cyclic nitrogen injection into the layer continued, until nitrogen break through into the producing wells and its content in the produced products reached 5% vol. The research results were processed in the form of graphical dependencies of reservoir pressure, gas flow rate and gas recovery coefficient for residual gas at the end of the cycle of nitrogen injection into the reservoir as a function of the number of such cycles. The research results indicate a significant effect on the gas recovery coefficient for the residual gas of the duration of the cycle of nitrogen injection into the reservoir and the ratio of rates of nitrogen injection and gas production, with an increase in which the coefficient of gas output gradually decreases. According to the research results, the optimal parameters of the process of nitrogen injection into the reservoir should be chosen on the basis of technological results, as well as technical and economic calculations.