Category Archives: Uncategorized

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Azimi published her 1st paper in PermLab

Category : Uncategorized

Congrates Zahra Azimi for her first publication in PermLab team. Zahra investigated  cross-linked polymer gels as a temporary plugging agent to control the leakage of fluid during drilling, completion, and workover operations. In this study, various concentrations and size of silica nanoparticles are introduced into the sulfonated polyacrylamide (SPAM)/chromium (III) acetate system to produce a nanocomposite with enhanced mechanical properties. First, the rheological behavior of gelant and viscoelastic properties of synthesized nanocomposites are investigated. Then, the surface chemistry and morphology of the synthesized gels is evaluated by Fourier transform infrared (FTIR) spectroscopy and field emission scanning electron microscopy (FESEM), respectively. Finally, the maximum sealing differential pressure for gels for temporary plugging of a wellbore is measured by applying differential pressure across the nanocomposite gel in a designed set-up. The results showed that the precrosslinking reaction and the gelant viscosity are directly related to the size and concentration of the silica nanoparticles as well as the wellbore temperature. Moreover, it is demonstrated that nanocomposites containing 20-30 nm sized particles have a higher mechanical strength and plugging capability in comparison to composites containing silica particles with sizes of 7-10 nm and 60-70 nm.

 


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Modeling reaction flow in porous media

Category : Uncategorized

Congratulations to Hossein Younesian-Farid, Msc student of petroleum engineering, for his recently published work about reaction flow of pH-sensitive polymer flooding in Petroleum Science & Engineering.

 

In this study, he developed a mathematical model to predict the acid pre-flush behavior before pH-triggered polymer flooding. Convection, diffusion, and homogeneous/heterogeneous geochemical reactions for a slightly compressible fluid flow in porous media was formulated.  The introduced model was validated against the experimental data. He simulated the injection of several acids (strong and weak acids) into a carbonate rock under different flow conditions (i.e., different Damkohler numbers). The obtained pH values reveal that weak acids can provide better results for acid pre-flushing in carbonate formations.

Figure: Different steps of pH-triggered polymer flooding. a) Water breakthrough during conventional water flooding process because of its flowing through high permeability areas; b) acid pre-flush in order to decrease the pH of the high permeable areas; c) Injection of pH-triggered polymer that has low viscosity in an acidic environment; d) Post water flooding with the  higher sweep efficiency in comparison to (a).