Petroleum Engineering – Drilling
Afshar Alihosseini; Ali Hassan Zadeh; Majid Monajjemi; Mahdi Nazary Sarem
Abstract
Wellbore stability is one of the challenges in the drilling industry. Shale formation is one of the most problematic rocks during drilling because the rock has very low permeability and tiny pores (nanometers). This study assesses the viability of the alumina nanoparticles (Al2O3) in water-based mud. ...
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Wellbore stability is one of the challenges in the drilling industry. Shale formation is one of the most problematic rocks during drilling because the rock has very low permeability and tiny pores (nanometers). This study assesses the viability of the alumina nanoparticles (Al2O3) in water-based mud. The effectiveness of alumina nanoparticles as a mud additive in improving the rheological properties in water-based drilling mud is investigated. The alumina nanoparticles have specific chemical and physical properties, such as high compressive strength, high hardness, and high thermal conductivity. These properties improve the properties of water-based drilling mud, reduce filtration loss, and meet environmental regulations. The results of experimental data show that alumina nanoparticle improves rheological properties such as yield point gel strength (GEL 10 s, Gel 10 min) of water-based drilling that can be utilized to enhance the significant feature of drilling mud, particularly in rheology and filtration. Preliminary data demonstrated that alumina nanoparticles, a nano additive, possess proper properties like thermal stability, rheology enhancement, fluid loss control, and lubrication. It is likely to encounter shale formation plug and significant improvement formation pressure. In addition, alumina nanoparticles reduced 60% API/HPHT fluid loss by 60% compared to the blank sample. The most striking feature is that nanofluid improved shale integrity between 60% and 70% compared to the blank sample. Further, the experimental data of the CT scan show that the mud cakes formed by each of fluid samples, including nanoparticles containing alpha- and gamma-alumina base are more cohesive and cause an integrated filter cake on the well.
Petroleum Engineering
Yavar Karimi; Ali Reza Solaimany Nazar
Abstract
The influences of several operating factors on the viscosity of the Isfahan refinery waxy crude oil sample are studied through conducting some rheological shear rotational tests. The Taguchi design method is adopted to determine the impact of factors such as shear rate, temperature, cooling rate, wax ...
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The influences of several operating factors on the viscosity of the Isfahan refinery waxy crude oil sample are studied through conducting some rheological shear rotational tests. The Taguchi design method is adopted to determine the impact of factors such as shear rate, temperature, cooling rate, wax content, and asphaltene content on the viscosity of the waxy crude oil. The results show that temperature with a contribution of 53.61% is the most influential factor. The wax content, shear rate, and asphaltene content have a contribution of 20.86, 14.75, and 3.11% respectively. The cooling rate does not have a statistically significant effect on the viscosity. The results of the rheological oscillatory tests confirm that the temperature and wax content change the viscoelastic properties of the waxy crude oil completely. An increase in the wax content from 12 to 22 wt.% raises the wax appearance temperature (WAT) from 19.1 to 34.9 °C and improves the gel point from 13 to 34.1 °C. By decreasing the temperature or increasing wax content, the viscoelastic nature of the oil sample changes from a viscoelastic fluid to a viscoelastic solid.
