Understanding the Shaffer BOP
The Shaffer BOP is a specialized valve that is used to control and also seal gas and oil wells. They are designed to handle flows that are uncontrolled and also pressures that are erratic. Including a BOP in the system is important as it provides and acts as a fail-safe to the system. They not only provide safety to the equipment used in drilling the well but also to the crew involved and the environment as well. The BOP has different functions as explained below.
1. To seal around the drill pipe – This is the most common function of the Shaffer BOP. It has ram pipe preventers and annular preventers that help it fulfill this function. The functionality of the ram pipes can be limited on a few instances for example when closing on the drill collars, the perforation guns or the tool joints among other instances.
2. To seal a hole that is open – This function is only played out in situations where the drill pipe is not running through the Shaffer BOP. The well will be sealed by means of the shear ram. As you may well know the annular preventers have been claimed to be able to seal an open hole.
3. To seal off the well and shear the drill pipe – Before sealing off the well a drill pipe has to undergo a shearing process. This is often the last alternative when the control of the well is lost. It may happen in response to a kick in the wells. The response is often by the ram and annular preventers of the Shaffer BOP.
Generally a Shaffer BOP is designed to either close a wellbore that is open, cut through a drill pipe or to seal, in the well, around tubular components. Other than the above some of the basic and primary uses of the BOP’s can be; to ensure the well fluid is confined to the well; to allow withdrawal of fluids from the well in a controlled manner and in controlled volumes; to provide a way for fluid to be added to the wells.
The preventer systems also have other functions in addition to the others. They monitor the pressure in the wellbores and also help regulate it. They also ensure the drill string is centered and also hang it off. In case an emergency arises, they are used to severe the drill pipes or the casings.