Wireline pressure control equipment can be available in two basic categories: they can be part of a standardized range of wireline pressure control equipment products, or they can be specially designed and made to fit in exactly with a customer’s requirements.
The equipment appears in a wide range of sizes, typically from two and a half inches inside diameter to nine inches inside diameter. The products can range from the very simple to the highly complex, depending on their specific use and function. It is necessary for wireline pressure control equipment to be designed and produced so that it is able to withstand excessive pressures and resist excessive corrosion within the well.
Pressures may be as high as 15,000 pounds per square inch, or even higher. Temperatures can also fluctuate and can be found in extreme ranges. Wireline pressure control equipment must be manufactured to withstand everything that is thrown at it. In any wireline operation it is necessary to maintain the pressure in the oil well. This is achieved by use of a stuffing box, or packing gland.
The stuffing box essentially allows the wireline to move freely up and down within the well, confining the fluids and gases within the wellbore and without losing the pressure inside. As a primary element of this equipment, the stuffing box has several important tasks to perform. It has to maintain well pressure while allowing braided wire to move freely through it.
As the braided wire is not uniform in diameter, this presents a problem that requires special attention. Packing elements made of rubber form a seal around the wire in the first instance. A wireline valve forming a second barrier seal is also required.
If a risk of failure of the stuffing box happens or is suspected, this can be closed around the wire to prevent excessive pressure loss. The wireline valve also requires a grease injection head positioned above it, especially in the case of braided wire, to guarantee a proper and acceptable seal. Western Pressure Controls is a reputed firm which offers premium quality wireline pressure control tools and equipment for commercial industry.
A wireline blowout preventer can produce a tight seal around slick line or braided cable. It is positioned between the lubricating assembly and the wellhead. Two opposing horizontal ram assemblies are commonly used to compress an effective tight seal around the wireline. This part of the equipment has the effect of containing and controlling the well pressure. Apart from the wireline pressure control equipment, the pressure inside an oil or gas well is controlled by drilling fluid pressure. Both components work together to provide satisfactory and safe overall pressure control.
The well hole must have enough drilling fluid pressure to overcome the formation pressure, the pressure exerted inside the well by oil, gas and water, for the drilling operation to proceed with safety. If this is not the case and the formation pressure exceeds the drilling fluid pressure, a blowout is possible. This is where the blowout wireline pressure control equipment comes into effect, sealing the well and containing the pressure.