Oil drilling techniques involve various methods to extract crude oil from underground reservoirs. The most common technique is rotary drilling, where a drill bit is rotated to penetrate the earth's surface. This method uses a drilling fluid, or mud, to cool the bit, remove cuttings, and maintain pressure in the well. Another technique is directional drilling, which allows operators to drill at various angles rather than straight down. This method is useful for reaching oil deposits that are not directly beneath the drilling site. Both techniques are essential for maximizing oil recovery while minimizing environmental impact.