Mechanism and phase behavior of retrograde condensation inhibition by secondary gas injection in the Yaha condensate gas reservoir
Author(s): Zhu Zhongqian, Research Institute of Exploration and Development, Tarim Oilfield Company, PetroChina
Pages: 60-65
Year: 2015 Issue: 5
Journal: Natural Gas Industry
Keyword: Tarim Basin; Yaha condensate gas reservoir; MDT; Secondary gas injection; Retrograde condensation loss; Solubilization swelling; Extraction; Recovery factor;
Abstract: In order to reduce the retrograde condensation loss resulted from formation pressure lower than dew point pressure due to insufficient gas re-injection rates of condensate gas reservoirs,based on the samples taken from the retrograde condensation loss monitoring well of Yaha condensate gas reservoir in the Tarim Basin by Modular Formation Dynamics Tester(MDT),a method of studying the mechanism and phase behavior of retrograde condensation loss inhibition by secondary cyclic gas injection in Yaha condensate gas reservoir was established by using the PVT phase state experimental test and simulation techniques,and applied to evaluate the feasibility and effectiveness of improving the condensate oil recovery degree of this condensate gas reservoir.Based on laboratory recurrence of retrograde condensate oil and remaining condensate gas system under present formation pressure,their chromatographic composition,phase behavior and p-T phase diagram were measured respectively;the gas injection solubilization expansion,multicontact extraction and experiments of gas injection extraction were conducted for retrograde condensate oil and formation remaining condensate gas respectively;the non-equilibrium phase behavior experiment of dry gas injection mass transfer diffusion process was also conducted for the remaining equilibrium condensate gas in the formations the phase behavior mechanisms of inhibiting the retrograde condensation loss,reducing the retrograde condensate oil saturation and making the condensate oil reverse by using secondary cyclic gas injection were analyzed.It is recommended to keep the injection gas pressure higher than the dew point at the time of secondary cyclic gas injection development.When 0.82 PV is reached,the cumulative recovery of condensate oil would increase by13.55%.This study results provide important technological support for the production enhancement in the Yaha condensate gas reservoir.
Pages: 60-65
Year: 2015 Issue: 5
Journal: Natural Gas Industry
Keyword: Tarim Basin; Yaha condensate gas reservoir; MDT; Secondary gas injection; Retrograde condensation loss; Solubilization swelling; Extraction; Recovery factor;
Abstract: In order to reduce the retrograde condensation loss resulted from formation pressure lower than dew point pressure due to insufficient gas re-injection rates of condensate gas reservoirs,based on the samples taken from the retrograde condensation loss monitoring well of Yaha condensate gas reservoir in the Tarim Basin by Modular Formation Dynamics Tester(MDT),a method of studying the mechanism and phase behavior of retrograde condensation loss inhibition by secondary cyclic gas injection in Yaha condensate gas reservoir was established by using the PVT phase state experimental test and simulation techniques,and applied to evaluate the feasibility and effectiveness of improving the condensate oil recovery degree of this condensate gas reservoir.Based on laboratory recurrence of retrograde condensate oil and remaining condensate gas system under present formation pressure,their chromatographic composition,phase behavior and p-T phase diagram were measured respectively;the gas injection solubilization expansion,multicontact extraction and experiments of gas injection extraction were conducted for retrograde condensate oil and formation remaining condensate gas respectively;the non-equilibrium phase behavior experiment of dry gas injection mass transfer diffusion process was also conducted for the remaining equilibrium condensate gas in the formations the phase behavior mechanisms of inhibiting the retrograde condensation loss,reducing the retrograde condensate oil saturation and making the condensate oil reverse by using secondary cyclic gas injection were analyzed.It is recommended to keep the injection gas pressure higher than the dew point at the time of secondary cyclic gas injection development.When 0.82 PV is reached,the cumulative recovery of condensate oil would increase by13.55%.This study results provide important technological support for the production enhancement in the Yaha condensate gas reservoir.
Related Articles