Wellhead is the critical piece of equipment installed at the surface of an oil, gas, or water well that serves as the primary structural and pressure containing interface between the underground reservoir and the surface production facilities. It consists of heavy steel components, including casing heads, tubing heads, valves, and often a Christmas tree assembly bolted or welded together atop the final string of casing that has been cemented into the borehole. The wellhead’s main functions are to support and suspend the weight of the casing and tubing strings hanging below it, provide a sealed pressure barrier to contain the fluids and gases from the reservoir, and allow controlled access for drilling, completion, production, intervention, or injection operations. Equipped with multiple high-pressure valves, chokes, and pressure gauges, it enables operators to safely regulate flow, shut in the well in emergencies, or connect the well to flowlines, separators, or pipelines. In essence, the wellhead is the fail-safe “cap” that transforms a drilled hole into a controllable, producing well while protecting both personnel and the environment from uncontrolled releases of hydrocarbons or formation fluids.
