| Autor: |
Faruk Civan, Eugene A. Spinler, Omar Patino, Subhash N. Shah, David R. Zornes |
| Rok vydání: |
2003 |
| Předmět: |
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| Zdroj: |
All Days. |
| DOI: |
10.2118/80271-ms |
| Popis: |
This paper presents a practical methodology and its verification for determination of the mechanisms and parameters of chemically induced formation damage. It is based on interpretation of laboratory core flood tests by diagnostic straight-line plotting schemes. Laboratory tests were conducted to measure the permeability impairment and effluent conditions as a function of time by flooding sandstone and limestone outcrop rock samples with various alkaline solutions (NaOH, KOH, NaSiO4) and alcohol (ethanol) as might be used for improved oil recovery. The single-phase permeability variation data were plotted according to prescribed diagnostic straight-line plotting schemes proposed by Wojtanowicz et al. and Civan. Plots that result in satisfactory straight-line trends reveal the predominate mechanisms of the formation damage. Further, the values of the parameters of the governing formation damage processes are determined from the intercept and slope of the straight-lines. Higher pH solutions were observed to have caused greater reductions in rock permeability. Civan's model better described the permeability variation due to scale dissolution and precipitation processes. The Wojtanowicz et al. model identified the formation damage mechanisms as pore surface deposition and sweeping. Different rock damage conditions were observed for the initial and the later test periods, indicating that more than one formation damage mechanism was involved. The analysis of the same experimental data reveals that a numerical model such as UTCHEM will require significantly more information to perform a similar analysis of the laboratory flood results. However, the diagnostic equations provide a practical and rapid means for the determination of the formation damage mechanisms. The methodology developed in this paper can be used for rapid detection and quantification of the formation damage mechanisms from core tests. The technique can be useful in the design of alkaline-surfactant-polymer (ASP) and/or micellar flooding chemical systems for field applications. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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