Development of a Correlation for the Estimation of Condensate to Gas Ratio CGR and Other Key Gas Properties From Density/Molecular Weight

Abstract

Condensate to Gas Ratio (CGR) is a measure of liquid content of a naturally occurring hydrocarbon mixture that is classified as gas condensate at reservoir conditions. It is also one of the most important parameters that impacts the economics of gas projects. In many cases, especially in the case of stranded gas, significant project value will be drawn from the liquid content of the gas. There are number of difficulties in measuring the CGR of a gas stream in the laboratory, or sometimes simply the value may not be known. Some of the difficulties in lab processes (but not limited to) originate from:1. Non-equilibrium flash and carry-over 2. Amount of the fluid used (volume constraints and errors) In this paper, we have developed a simple easy to use semi-empirical correlation that accurately estimates the CGR of a gas condensate system using fluid densities (or molecular weights). Fluid densities can be obtained either from gradient measurements or directly from the laboratory measurements. To our knowledge, there is no equivalent correlation published in literature. The proposed correlation can be used for: a) Exploration support to estimate the CGR ranges (valid up to CGR = 350 STB/MMSCF). b) Form a yard-stick to quality-check laboratory experiments. c) Generate necessary input parameters for other key gas properties: such as Z-factor, gas formation volume factor, Molecular weight, gas viscosity and even compositions. d) Reconciliation of contaminated samples against the measured or estimated fluid densities.

Acoustic Velocity Measurements and Interpretation for Challenging Fluid Systems

“…black oil, volatile oil/condensate). EOS prediction of acoustic velocity for the low density fluids fit the relationship with κ T indicated in Eqn 8 very well in the numerical model, which for condensates is a known issue related to PVT analysis [21]. Further investigation is needed to understand if the physical properties of the fluid cause the deviation from the theoretical prediction (i.e.…”

“…condensates) does not seem to indicated in Eqn 8 very well. Difficulties arose in assessing the quality of the data input el, which for condensates is a known issue related to PVT analysis [21]. 1/κ T ) region separately, the exponent of the velocity term corresponding to the data in the lower compressibility region decreases to 2.187 (see Figure 15).…”

“…black oil, volatile (i.e. condensates) does not seem to Difficulties arose in assessing the quality of the data input el, which for condensates is a known issue related to PVT analysis [21]. Further investigation if the physical properties of the fluid cause the deviation from the theoretical prediction…”

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

“…The condensate/gas ratio of Fluids A and B are 12.8 and 30.6 STB/MMscf, respectively. Both are considered to be lean gas condensates (Dindoruk 2012). Fig.…”