Phase-Behavior Study of Hydrocarbon/Water/Methanol Mixtures at Reservoir Conditions

Abstract

Summary This paper presents a study of gas/condensate hydrocarbon mixtures and the effect of water, methanol, and isopropanol on their phase behavior. Only sparse data are available on the phase behavior of hydrocarbon/water/methanol mixtures at the high temperatures typical of these reservoirs. Such data are needed for compositional reservoir simulations of well treatments to optimize the performance of solvent treatments of blocked wells. Constant-composition expansion (CCE) experiments were performed to measure the phase behavior of hydrocarbon/water/methanol mixtures up to 300°F. The effects of temperature, pressure, and water and methanol concentration on the phase behavior were measured. The Peng-Robinson equation of state (EOS) was used to model hydrocarbon/water/methanol mixtures. The binary interaction parameters were tuned to fit the data and were found to show a linear variation with temperature. The binary interaction parameters and temperature-dependent volume-shift parameters are the key parameters to model these complex polar mixtures. Both the classical van der Waals and the Huron-Vidal (Huron and Vidal 1979) mixing rules were used and were found to give good agreement with the data. Phase-behavior experiments performed on hydrocarbon/water/isopropanol mixtures showed that isopropanol decreases the aqueous-phase volume fraction and increases the liquid-hydrocarbon-phase volume fraction compared with the analogous hydrocarbon/water/methanol mixtures. These data are needed to predict the conditions under which methanol/isopropanol treatments can be applied successfully in gas wells to remove water and condensate blockage.

An Eos-Based Numerical Simulation of Thermal Recovery Process Using Unstructured Meshes

“…Binary interaction coefficients and volume shift parameters are modified for the EOS for this kind of calculation. Bang (2005) showed good agreement between experimental data for the hydrocarbon/water and hydrocarbon/water/methanol systems at different temperatures. They modified the binary interaction coefficient and the volume shift parameter for EOS to match the experimental data.…”

Mitigation of the Effects of Condensate Banking: A Critical Review

“…Extensive laboratory work was performed by many researchers. The reported experimental studies started at room temperatures (Tang and Firoozabadi 2003), and then were continued by many researchers at higher temperatures of up to 161 C (Fahes and Firoozabadi 2007;Noh and Firoozabadi 2008;Bang et al 2010b). Several fluorinated polymers and surfactants were evaluated.…”

“…Bang et al (2009) found the pressure drop across the core decreased after treating the core samples with fluoropolymer, which indicates that there was an increase in the relative permeability to gas (twofold increase) and the treatment was durable and efficient. In another study, Bang et al (2010b) found that optimal solvents for wettability-alteration chemicals to stimulate the Berea sandstone were the mixture of 2-butoxyethanol and ethanol and the mixture of isopropyl alcohol (IPA) and propylene glycol. Bang et al (2010b) and Wu and Firoozabadi (2010b) found that the water salinity and the type of salt in brine will influence the performance of the fluorochemical and the final change in the wettability of the rock surface.…”

“…In another study, Bang et al (2010b) found that optimal solvents for wettability-alteration chemicals to stimulate the Berea sandstone were the mixture of 2-butoxyethanol and ethanol and the mixture of isopropyl alcohol (IPA) and propylene glycol. Bang et al (2010b) and Wu and Firoozabadi (2010b) found that the water salinity and the type of salt in brine will influence the performance of the fluorochemical and the final change in the wettability of the rock surface. Fahimpour et al (2012a, b) found that alcohol-based solvents were more effective than brine-based solvents for use with wettability-alteration chemicals.…”

Treatment of Condensate and Water Blocks in Hydraulic-Fractured Shale-Gas/Condensate Reservoirs

“…Bang et al (2006) measured the gas and oil relative permeabilities over a wide range of capillary numbers. Bang et al (2008) found that condensate buildup in the fractures can significantly reduce the productivity of fractured wells. The steady-state relative permeability in propped fractures is typically on the order of 0.1, which is approximately the same as in the reservoir rock after condensate buildup.…”