The application of silicone oil in oil drilling is extremely extensive and critical. Its unique physical and chemical properties provide multiple solutions for drilling operations, which significantly improves drilling efficiency and safety.


In the drilling fluid system, silicone oil, as one of the core treatment agents, plays a central role in stabilizing the well wall and regulating rheology.Taking methyl silicone oil as an example, the long-chain alkyl and silicone-oxygen bonds in its molecular structure give it low surface tension characteristics, which can form a dense lubricating film in the drilling fluid, effectively reducing the coefficient of friction between the drilling tool and the well wall.Experimental data show that adding 1.5%-2% methyl silicone oil to the polysulfonated heavy drilling fluid can reduce the friction coefficient from 0.1405 to 0.0875, a decrease of 37.7%. At the same time, it significantly inhibits the dispersion of mudstone and improves the ability of the drilling fluid to carry cuttings.This optimization of lubrication performance not only reduces the wear of drilling tools, but also avoids complex accidents such as stuck drilling. In deep well drilling in the Gulf of Mexico, synthetic-based drilling fluids modified with silicone oil are used to successfully achieve stable operation in a high temperature environment of 220℃.


Silicone oil also performs well in terms of well wall stability.The flexibility and hydrophobicity of its molecular chain can penetrate into the micro-cracks of mud shale to form a chemical blocking layer. Combined with the water-soluble advantages of polyether modified silicone oil, it can effectively adjust the density and viscosity of the drilling fluid and prevent the collapse of the well wall.In the drilling of high-steep tectonic wells in Northeast Sichuan, the silicone oil-based drilling fluid system controls the well diameter expansion rate within 5%, which is 12 percentage points lower than the traditional system, significantly improving the quality of the borehole.


For high-temperature and high-pressure formations, silicone oil exhibits excellent temperature and salt resistance.Through the molecular structure design, the modified silicone oil can maintain stable performance in an environment of 180℃ and 30% brine. Its temperature and calcium resistance characteristics control the filtration loss of drilling fluid within 5mL, and the thickness of the mud cake is reduced by 40%, which provides a technical guarantee for the development of deep oil and gas resources.In addition, silicone oil, as a defoamer, can quickly eliminate the foam generated during the circulation of drilling fluid and avoid the well control risks caused by gas intrusion. In shale gas horizontal well drilling, silicone oil defoamers shorten the foam half-life to less than 30 seconds, ensuring the continuous stability of drilling fluid performance.