Category Archives: New publication

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Matrix acidizing of sandstones

Category : New publication

Hossein Younesian-Farid published his 2nd paper in the JPSE.  In this study, the interaction of citric acid, as a weak acid, with a sandstone core containing ankerite cement was investigated during matrix acidizing. The model, developed in Python, implemented a global implicit numerical approach to consider acid-rock geochemical interactions. The effect of multi-step dissociation of citric acid on lowering rock pH was investigated. The sugar-lump approach was used to estimate the behavior of the ions concentration originated from the variation of the reactive surface area (RSA). Moreover, the model outputs were validated against matrix sandstone acidizing experiments from the literature.


The concentration of non-ionized acetic acid across the core during the injection of citric acid.

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Speed-up of Soxhlet Core Cleaning in RCAL

Category : New publication

Pouya Soltani has published his first paper at PermLab in the SPE Reservoir Evaluation & Engineering Journal. The main idea of this paper is to introduce a methodology of measuring the cleaning time that can be implemented as a routine screening tool in RCAL projects to nominate the proper solvent, which can reduce the Soxhlet cleaning time.

The process of running core analysis experiments (in both RCAL and SCAL) is very time-consuming. As all plug samples should be cleaned during the RCAL phase; therefore, finding of a solvent that can speed-up this process is necessary. The cleanliness of a core sample during Soxhlet extraction is usually determined by monitoring the color of solvents, qualitatively. The main contribution of this study was to propose a methodology during RCAL to nominate the best solvent during the Soxhlet cleaning experiments. By introducing a state-of-the-art quantitative method, the cleaning time of different solvents (i.e., tetrachloroethene, acetone, toluene, chloroform, xylene, and n-hexane) was investigated. This quantitative method is based on turbidity measurement of the solvent that siphons periodically from the Soxhlet extractor. Moreover, the wettability alteration of the implemented solvents was monitored by contact angle measurements.

Designed Soxhlet setup. a) Heater, b) Round-bottom flask, c) Two-neck extractor, d) Condenser, e) Sampling Syringe. The solvent samples are taken from part e by a needle syringe.


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Collaboration between PermLab and PMEAL

Category : New publication

The close collaboration between PermLab at Tarbiat Modares University and PMEAL at the University of Waterloo is continuing. By assigning joint-supervisors for the PermLab members, this collaboration is being expanded. At PermLab, our area of interest is characterizing carbonate reservoirs at pore-scale using OpenPNM, an open-source software package developed by PMEAL under the leadership of Prof. Jeff. Gostick at the University of Waterloo.

Recently, a new joint paper was accepted in theSPE Journal and we hope for more new outputs from this collaboration in the next future. This paper deals with reconstruction of vuggy carbonates by pore network modeling and image-based technique. The source code of this code can be downloaded from here.


Farhoodi did great in JNGSE

Category : New publication

Shahab Farhoodi, did great and published a very good paper (here) in Journal of Natural Gas Science & Engineering (JNGSE). We in this study payed attention to the analysis of the combined effect of geological heterogeneity and condensate drop out in condensate reservcoirs. A geostatistical approach was used to build reservoir models with different amount of heterogeneity. These models were simulated by a compositional reservoir simulator to generate pseudo-pressure data versus time of these heterogeneous models.


Condensate saturation, Scond, and pressure profile versus the radius from the wellbore, r, for a gas condensate reservoir. Different flow regimes are depicted during the production.

It was revealed that the intensity of the condensate formation around the wellbore is a strong function of the reservoir heterogeneity. The results showed that increasing of the model heterogeneity can entirely complicate the well-test responses when condensate drops near the wellbore region.


Bottomhole pressure and rate history of 10 days. The flowing and shut-in period is one day each.

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Geological Boundary Detection in JPSE

Category : New publication

Congratulations to Mohammad Amin Partovi, Msc student of petroleum engineering, for his recently published work about geological boundary detection from well-logs using pattern recognition techniques in Petroleum Science & Engineering.

In this study, we implemented an automatic well-to-well correlation approach based on pattern extraction from well-logs. The well-log patterns were recognized by calculating several statistical and fractal parameters. As a fractal parameter, we selected the wavelet standard deviation exponent, calculated by the discrete wavelet transform. Furthermore, to select the proper wavelet function, the energy to Shannon entropy ratio criterion was implemented. The statistical pattern recognition parameters of this study include average value, maximum to minimum ratio, coefficient of variation, and the trend angle of well-log data (i.e., Gamma ray log) in a window around the geological boundary. Moreover, the analysis of variance (ANOVA) tool and the Tukey multiple comparison method were implemented to evaluate the effectiveness of each parameter (i.e., fractal or statistical parameters) during the determination of boundary depths. The gamma ray logs from three wells of an oil field were used as a dataset for the evaluation of our algorithm. The outputs of our methodology were also compared with the new detrended fluctuation analysis (DFA) method, which show promising outcomes over it. The results show that the average value of the signal, among the analyzed parameters, is the most effective parameter; however, implementing the combination of all fractal and statistical parameters can improve the accuracy of the geological boundary detection.

 


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PermLab in IAMG2018

Category : New publication

Permlab has participated in IAMG2018, Olomouc, Czech Republic with two papers,

1-“Reconstruction of vugular carbonate rocks by pore network modeling and image-based network technique”, which was a collaboration between PermLab at TMU and PMEAL research group at Waterloo University.

2-“Modeling and simulation of geochemical reactions during acid pre-flush to improve conformance control of pH-sensitive polymer flooding” written by Hossein Younesian-Farid from PermLab.


Ali published his first paper

Category : New publication

Congrats to Ali Soltani for his publication in PhysicaA. This work models scaling & critical properties of percolation-like porous media. Both site & continuum systems with different well configurations were analyzed.