Perpustakaan Digital ITB

Mature gas wells face a significant problem with liquid loading, which occurs when the gas velocity falls below the critical limit required to elevate co-produced liquids to the surface. This study analyzes and compares the efficacy of two deliquefication techniques, namely surfactant (foam-assisted lift) injection and thermochemical fluid (TCF) injection, in reducing liquid loading in an established gas-condensate well situated in the Vuktylskoye field in Russia. The hyperbolic decline curve analysis estimates that the reservoir pressure will be around 2,367 psia as the field approaches its 25th year of production. Multiflash was used to characterize the fluid, and OLGA was used to conduct a multiphase flow simulation. The well was shut in at 47 hours and produced 50.8203 MMSCF of gas overall, indicating liquid loading in the base model. Injection of a surfactant reduced the interfacial tension from 72 to 23.38 dyne/cm, prolonging the shut-in period to 50.33 hours while resulting in a slight gas gain of 12.90 MSCF. TCF injection resulted in a 17.48 MSCF increase in gas, and it increased the well floor temperature from 60.85°C to 110.85°C, delaying shut-in to 53.33 hours. Sensitivity analysis revealed that TCF injection was the most important factor. Well shut-in was not avoided by any technique alone. The most effective surfactant and TCF settings, when combined, showed a powerful synergistic impact. This combination was successful in avoiding well shut-in over the whole simulation period and boosting cumulative gas production to 62.8 MMSCF, which represents a gain of 11.98 MMSCF (approximately 24%) over the base case. These results indicate that concurrently resolving fluid viscosity and interfacial tension offers a considerably more thorough and efficient solution to liquid loading in developed gas-condensate wells.