TY - GEN
T1 - A gas kick model that uses the thermodynamic approach to account for gas solubility in synthetic-based mud
AU - Manikonda, Kaushik
AU - Hasan, Abu Rashid
AU - Rahmani, Nazmul H.
AU - Kaldirim, Omer
AU - Obi, Chinemerem Edmond
AU - Schubert, Jerome J.
AU - Rahman, Mohammad Azizur
N1 - Publisher Copyright:
© MEDT 2021.All right reserved.
PY - 2021
Y1 - 2021
N2 - This paper presents a rigorous, mechanistic model for simulating a gas kick, that uses the thermodynamic approach to account for gas solubility. This thermodynamic solubility model uses the pressure and temperature data from the kick simulations and estimates the mole fraction of various gas components in the liquid phase. We validated these gas solubility results using Aspen HYSYS, a commercial chemical process simulation software. The thermodynamic solubility model presented in this paper assumes a pure-methane kick and applies the concepts of phase-equilibrium and fugacity to estimate the amount of dissolved gas in the drilling fluid. Application of fugacity equilibrium between the gas and liquid phases, in conjunction with the Peng-Robinson equation, gives the liquid phase mole fraction of methane. The analytical kick model uses the Hasan-Kabir two-phase flow modeling approach to describes the changes in pressure during kick migration, at various points in the annulus. Since the expansion of the gas bubbles depends on the variation in pressure, these studies also lead to pit gain estimates. A comparison between our model results and HYSYS values for methane liquid-phase mole fraction showed a maximum 8% deviation with complete agreement on bubble point (Pb) pressure and location estimates. Similarly, our model calculated the solution gas-oil ratio (Rs), with a maximum divergence of 3% from HYSYS estimates. From the comparison studies with other empirical Bo & Rs correlations, we note that the estimates of our model agreed best with those of O'Bryan's (O'Bryan 1988) correlations. Many numerical kick simulators exist today, but they are notoriously time-consuming, limiting their on-field utility. Our kick simulator's simplicity makes it potentially useful for on-field well control decisions. Most of these existing numerical simulators ignore the effects of kick solubility in synthetic-based muds. In the few models that do not ignore solubility, the approach to accounting for gas solubility and mud swelling is empirical, limiting their usage under conditions beyond the range of the source data used in developing these correlations. The mud swelling calculation approach we developed does not have these pressure and temperature range limitations.
AB - This paper presents a rigorous, mechanistic model for simulating a gas kick, that uses the thermodynamic approach to account for gas solubility. This thermodynamic solubility model uses the pressure and temperature data from the kick simulations and estimates the mole fraction of various gas components in the liquid phase. We validated these gas solubility results using Aspen HYSYS, a commercial chemical process simulation software. The thermodynamic solubility model presented in this paper assumes a pure-methane kick and applies the concepts of phase-equilibrium and fugacity to estimate the amount of dissolved gas in the drilling fluid. Application of fugacity equilibrium between the gas and liquid phases, in conjunction with the Peng-Robinson equation, gives the liquid phase mole fraction of methane. The analytical kick model uses the Hasan-Kabir two-phase flow modeling approach to describes the changes in pressure during kick migration, at various points in the annulus. Since the expansion of the gas bubbles depends on the variation in pressure, these studies also lead to pit gain estimates. A comparison between our model results and HYSYS values for methane liquid-phase mole fraction showed a maximum 8% deviation with complete agreement on bubble point (Pb) pressure and location estimates. Similarly, our model calculated the solution gas-oil ratio (Rs), with a maximum divergence of 3% from HYSYS estimates. From the comparison studies with other empirical Bo & Rs correlations, we note that the estimates of our model agreed best with those of O'Bryan's (O'Bryan 1988) correlations. Many numerical kick simulators exist today, but they are notoriously time-consuming, limiting their on-field utility. Our kick simulator's simplicity makes it potentially useful for on-field well control decisions. Most of these existing numerical simulators ignore the effects of kick solubility in synthetic-based muds. In the few models that do not ignore solubility, the approach to accounting for gas solubility and mud swelling is empirical, limiting their usage under conditions beyond the range of the source data used in developing these correlations. The mud swelling calculation approach we developed does not have these pressure and temperature range limitations.
UR - http://www.scopus.com/inward/record.url?scp=85118234092&partnerID=8YFLogxK
U2 - 10.2118/202152-MS
DO - 10.2118/202152-MS
M3 - Conference contribution
AN - SCOPUS:85118234092
T3 - Proceedings of the SPE/IADC Middle East Drilling Technology Conference and Exhibition
BT - SPE/IADC Middle East Drilling Technology Conference and Exhibition 2021, MEDT 2021
PB - Society of Petroleum Engineers (SPE)
T2 - SPE/IADC Middle East Drilling Technology Conference and Exhibition 2021, MEDT 2021
Y2 - 25 May 2021 through 27 May 2021
ER -