Khabat M. Ahmad
Abstract
Permeability decline related with fine migration is one of the most widespread phenomenon that occurs in most oil reservoirs. Fine migration is intensive in sandstone reservoir, but ...
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Permeability decline related with fine migration is one of the most widespread phenomenon that occurs in most oil reservoirs. Fine migration is intensive in sandstone reservoir, but frequently misinterpreted. Movement of fine particles might be problamatic to identify and even not easy to predict and interpret. The main goal of this study is to investigate the influence of flow rate and fluid alakalinity on petrophysical properties of selected reservoir sandstone. To determine the types of clay minerals with calculating the percentage of each types and the shape, position, and distribution within the rock matrix, first selected core samples were examined by X-ray diffraction and scanning electron microscopy. This is also to identify the bulk mineralogy and clay fraction.. The result of this study shows that higher alakalinity fluid flow through reservoir standtone might cause a significant reduction on permeability. While at low pH fluid, the degree of damage is less damage than high pH value. However, the reduction on permeability was estimated by conducting a series of core flood experiments by injecting alkaline solution (pH 9 and pH 11) with stepwise increasing flow rate (50, 100, 200 ml/ h). Furthermore, the basic petrophysical properties of such porosity and initial permability were measured prior to testing. Ultimately, a series of core flooding were also conducted to investigate the influence of clay mineral content, pH and flow rate on sandtone reservoir permeability. High pH solutions significant permeability reductions were recorded, during the flood of pH 11 alkaline solution reductions as high as 36- 50-% were obtained while, the degree of damage was observed less severe with (pH9). Hence, the magnitude of damage was more severe with high flow rate and higher pH. The result shows that the clay minerals present in the cores were characteristics to fine migration thus causing negative impact on reservoir characteristics.
