Interwell Tracer Test To Determine Residual Oil Saturation In A Gas-Saturated Reservoir. Part I: Theory And Design

1991 ◽  
Vol 30 (03) ◽  
Author(s):  
J.S. Tang ◽  
B. Harker
Keyword(s):  
Tracer Test ◽  
Residual Oil ◽  
Oil Saturation ◽  
Residual Oil Saturation

Evaluation of Residual Oil Saturation With Use of Single Well Chemical Tracer Test Swctt For Estimation of Eor Efficiency. From Theory to Experiment

2021 ◽  
Author(s):  
Fedor Andreevich Koryakin ◽  
Nikolay Yuryevich Tretyakov ◽  
Vladimir Evgenyevich Vershinin ◽  
Roman Yuryevich Ponomarev
Keyword(s):  
Analytical Methods ◽  
Tracer Test ◽  
Hydrodynamic Modeling ◽  
Residual Oil ◽  
Tracer Studies ◽  
Oil Saturation ◽  
Residual Oil Saturation ◽  
Chemical Tracer ◽  
Single Well

Abstract This article provides a brief overview of the theory of tracer studies, describes approaches to the interpretation of tracer studies using both analytical methods and hydrodynamic modeling, compares the results of analytical and numerical interpretation. The article also describes the problems that arise during the interpretation of real case study.

scholarly journals MUSCL scheme for Single Well Chemical Tracer Test simulation, design and interpretation

2019 ◽  
Vol 74 ◽  
pp. 10 ◽  
Author(s):  
Benjamin Braconnier ◽  
Christophe Preux ◽  
Frédéric Douarche ◽  
Bernard Bourbiaux
Keyword(s):  
Numerical Scheme ◽  
Tracer Test ◽  
Time Shift ◽  
Residual Oil ◽  
Oil Saturation ◽  
Residual Oil Saturation ◽  
Chemical Tracers ◽  
Chemical Tracer ◽  
Single Well ◽  
Order Scheme

Our paper presents an improved numerical scheme to simulate Single Well Chemical Tracer Test (SWCTT) method. SWCTT is mainly applied to determine the residual oil saturation of reservoirs. It consists in injecting an aqueous slug of a primary tracer into the reservoir formation and displacing it at a certain distance from the well. This tracer is partly miscible with oil on the one hand, and generates in situ a secondary tracer on the other hand. As a consequence, a shift is observed between the primary and the secondary tracers arrival times when production is resumed. This time shift is used to evaluate the residual oil saturation. In our paper, we propose a numerical scheme based on a fractional time stepping technique to decouple the resolution of the phases mass conservation equations and the chemical tracers mole conservation equations. For the phases resolution, we use an implicit scheme to ensure stability and robustness. For the chemical tracers, we propose an explicit second-order scheme in time and in space via MUSCL technique to improve the tracers time-shift calculation. The proposed numerical method is implemented on a realistic simulation model consisting of a vertical well crossing a reservoir consisting of a stack of homogeneous layers. By reducing the numerical dispersion, the proposed scheme improves the accuracy of predicted concentration profiles, without significantly increasing the computation time. Finally, the advantages of using a second-order scheme for residual oil saturation assessment are discussed on the basis of a radial 1D mesh convergence study.

Relationship between Residual Saturations and Wettability using Pore-Network Modeling

2021 ◽  
Author(s):  
Prakash Purswani ◽  
Russell T. Johns ◽  
Zuleima T. Karpyn
Keyword(s):  
Contact Angle ◽  
Oil Recovery ◽  
Network Modeling ◽  
Pore Network ◽  
Residual Oil ◽  
Residual Saturation ◽  
Oil Saturation ◽  
Pore Network Modeling ◽  
Residual Oil Saturation ◽  
Eor Processes

Abstract The relationship between residual saturation and wettability is critical for modeling enhanced oil recovery (EOR) processes. The wetting state of a core is often quantified through Amott indices, which are estimated from the ratio of the saturation fraction that flows spontaneously to the total saturation change that occurs due to spontaneous flow and forced injection. Coreflooding experiments have shown that residual oil saturation trends against wettability indices typically show a minimum around mixed-wet conditions. Amott indices, however, provides an average measure of wettability (contact angle), which are intrinsically dependent on a variety of factors such as the initial oil saturation, aging conditions, etc. Thus, the use of Amott indices could potentially cloud the observed trends of residual saturation with wettability. Using pore network modeling (PNM), we show that residual oil saturation varies monotonically with the contact angle, which is a direct measure of wettability. That is, for fixed initial oil saturation, the residual oil saturation decreases monotonically as the reservoir becomes more water-wet (decreasing contact angle). Further, calculation of Amott indices for the PNM data sets show that a plot of the residual oil saturation versus Amott indices also shows this monotonic trend, but only if the initial oil saturation is kept fixed. Thus, for the cases presented here, we show that there is no minimum residual saturation at mixed-wet conditions as wettability changes. This can have important implications for low salinity waterflooding or other EOR processes where wettability is altered.

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