Graphical Determination of the Henry's Constant and the Diffusion Coefficient of Gases in Heavy Oils Using Late-Time Pressure-Decay Data

2014 ◽  
Author(s):  
Francisco Javier Pacheco Roman ◽  
S. Hossein Hejazi
Keyword(s):  
Diffusion Coefficient ◽  
Time Pressure ◽  
Late Time ◽  
Heavy Oils ◽  
Henry's Constant ◽  
Decay Data ◽  
Pressure Decay

Estimation of Solubility and Diffusivity of Gases in Heavy Oils by Use of Late-Time Pressure-Decay Data: An Analytical/Graphical Approach

SPE Journal ◽  
2015 ◽  
Vol 20 (04) ◽  
pp. 717-728 ◽  
Author(s):  
Francisco J. Pacheco-Roman ◽  
S. Hossein Hejazi
Keyword(s):  
Diffusion Coefficient ◽  
Gas Phase ◽  
Time Pressure ◽  
Early Time ◽  
Late Time ◽  
Heavy Oils ◽  
Time Data ◽  
Henry's Constant ◽  
Pressure Decay ◽  
Phase Pressure

Summary Solubility and diffusivity of gases in heavy oils, quantified by Henry's constant (Hij) and the diffusion coefficient (D), respectively, are essential properties for the design of recovery processes that require the injection of gas or vapor solvents into the reservoir. Data, obtained from various experimental procedures such as the pressure-decay technique (PDT), are used to estimate these two parameters. The PDT uses a pressure/volume/temperature (PVT) cell where the gas-phase pressure declines as gas diffuses into heavy oil following an early- and a late-time regime. Current approaches to analyze data from the conventional PDT are either graphical techniques based on early-time data or full numerical simulation. Early-time data, when the diffusing gas has not reached the bottom of the PVT cell, do not provide enough information to simultaneously estimate both the diffusion coefficient and Henry's constant. Hence, existing graphical procedures are limited to diffusion-coefficient estimation. In this paper, we propose a novel graphical technique to estimate the diffusion coefficient and Henry's constant by use of the late-time data from pressure-decay experiments. Our method is derived from the modeling of gas-phase pressure decay by use of Fick's second law and gas-phase mass-balance equations. We use the integral method to provide an approximate analytical solution to the set of equations. In addition, by use of the resultant solution, we develop a simple graphical method to directly estimate both the diffusion coefficient and Henry's constant. The estimated parameters through the proposed technique for methane/bitumen and carbon dioxide/bitumen experiments are in close agreement with those reported in the literature.

Estimation of concentration-dependent diffusion coefficient in pressure-decay experiment of heavy oils and bitumen

2011 ◽  
Vol 305 (2) ◽  
pp. 132-144 ◽  
Author(s):  
Seyyed M. Ghaderi ◽  
S. Hamed Tabatabaie ◽  
Hassan Hassanzadeh ◽  
Mehran Pooladi-Darvish
Keyword(s):  
Diffusion Coefficient ◽  
Heavy Oils ◽  
Pressure Decay

DETERMINATION OF DIFFUSION COEFFICIENT OF THE TURKISH TRONA IN WATER

1996 ◽  
Vol 05 (01) ◽  
pp. 3-11 ◽  
Author(s):  
GÜLHAYAT NASÜN-SAYGILI ◽  
HASANCAN OKUTAN
Keyword(s):  
Diffusion Coefficient

Lithium Ion Diffusion Through Glassy Carbon Plate

1997 ◽  
Vol 496 ◽  
Author(s):  
M. Inaba ◽  
S. Nohmi ◽  
A. Funabiki ◽  
T. Abe ◽  
Z. Ogumi
Keyword(s):  
Diffusion Coefficient ◽  
Glassy Carbon ◽  
Lithium Ion ◽  
Ion Diffusion ◽  
Irreversible Capacity ◽  
Oxidation Current ◽  
Current Curve ◽  
Carbon Plate ◽  
Lithium Ion Diffusion

ABSTRACTThe electrochemical permeation method was applied to the determination of the diffusion coefficient of Li+ion (DLi+) in a glassy carbon (GC) plate. The cell was composed of two compartments, which were separated by the GC plate. Li+ions were inserted electrochemically from one face, and extracted from the other. The flux of the permeated Li+ions was monitored as an oxidation current at the latter face. The diffusion coefficient was determined by fitting the transient current curve with a theoretical one derived from Fick's law. When the potential was stepped between two potentials in the range of 0 to 0.5 V, transient curves were well fitted with the theoretical one, which gaveDLi+ values on the order of 10−8cm2s−1. In contrast, when the potential was stepped between two potentials across 0.5 V, significant deviation was observed. The deviation indicated the presence of trap sites as well as diffusion sites for Li+ions, the former of which is the origin of the irreversible capacity of GC.

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