This is one of the best drilling 101 videos showing you drilling process from the beginning phase to plug and abandonment phase. Not only do you learn about drilling, this video briefly shows the overall field development phase. This video tends to focus on unconventional well. For educational purposes, our team provides full video transcript to help anybody learn the content clearly and effectively.
Jacking, which is one of operation modes for jack up, is a specific way to raise up a hull of a jack up rig so this article will describe about the basic of jacking and preloading operation.
Mat jack up units (figure 1) jack the mat to the seabed, in accordance with the ballasting procedure. When the mat is fully lowered, the hull is then jacked out of the water. After this is complete, the unit will then proceed to preload operations. It is vital that all independent leg units also perform preload operations before being jacked to the design air gap. The majority of independent leg units lack the capacity needed to fully elevate the Jack Up unit while the preload weight is still aboard. In these cases, the next step will be to jack the hull out of the water until a very small air gap is achieved- this should be at the very most 5 feet. Once this has been reached, then preload operations can continue.
Junk refers to any objects or debris which have been dropped into or lost in the hole. Junk can include all manner of things, from downhole tools and bottomhole assembly components, to bit cones, or even hand tools which have been accidentally dropped into the hole. In some cases, it may be clear what the junk is, such as when something has been visibly dropped down the hole. On the other hand, though, it may sometimes be unclear just what is causing the problem. While drilling is taking place, junk can be detected by an irregular torque, or by the drill being unable to move ahead when a new bit has been run. In order to remove any junk from a well, junk removal tools will be used depending on a particular condition of junk and wellbore.
There are three main ways that junk can be dealt with; which method is chosen will depend on the size of the junk itself, and how hard the formation is. The junk can be recovered whole, split into smaller pieces so that these pieces can be recovered or that they are too small to cause any additional issues, or finally pushed into the side of a soft formation or the bottom of a formation with a large enough rathole. If none of these are possible and the junk continues to interfere with well operations, then the well made need to be sidetracked or abandoned.
Turbine Motors work by harnessing the energy of a continuous flow of steam which passes through them. More specifically, drilling fluid travelling down the drillstem is deflected by the blades of a stator which is connected to the housing. This deflected fluid then flows over the blades of a rotor, which causes the drive shaft itself to rotate. The blades of both the rotor and stator are configured in the same way as a standard ventilation fan, but with the blades positioned in reverse. This is because a fan is designed to propel air outwards with a motor, whereas a turbine requires an input of air or liquid to turn its motor.
Mud or drilling fluid is pumped down the drillstring from the surface, until it enters the power section of the turbine. It then comes into contact with the stator blades, which cannot move since they are fixed to the turbine housing. The fluid’s momentum is therefore redirected to the rotor blades. This then moves the drive shaft to the drill bit, causing it to rotate. When the rotor blades perform their exit turns, the liquid is then directed into the next rotor/stator stage. Each turbine may include up to 400 of these stages, although a more typical figure is 100-250. Every stage will transmit the same amount of torque to the drive shaft, and uses up an equal amount of the total energy.
Figure 1 – Components of Turbine Motors, (oilandgasproductnews.com, 2015)
Positive-Displacement Motors (PDM) make use of a power generation section which is made up of a rotor/stator combination. In order to move a rotor part, a PDM requires hydraulic power from drilling fluid flowing through the power generation part. With a PDM, the stator and rotor work in tandem in the same way that gears do. The stator acts as the outer gear, and is made from a moulded elastomer featuring at least two lobes. The OD of the elastomer is protected by a secure metal casing. The rotor is positioned within the stator, and acts as an internal gear. This rotor is made of metal, and will have one less gear or lobe than the stator. Because of this difference, a cavity is created which is filled with drilling fluid when the PDM is downhole. This cavity acts as a wedge when it is put under pressure, and because the drilling fluid itself can’t be compressed, the force applied to the top of the wedge causes the rotor to move.