Mechanical & drilling

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Mechanical & drilling

Transcript of Mechanical & drilling

  • 1. VII Mechanical/ drillingRotating mechanical equipmentStatic mechanical equipmentDrillingGenerator and compressorDisipline leadVessel and seperators how coalescing oil water separators worksCranesMechanical and maintenance

2. Rotating mechanicalequipment Rotating equipment is the general classification of mechanicalequipment that is used to add kinetic energy to a process. Theaddition of kinetic energy may be needed to move material from onepoint to the next or to agitate the material. 3. Statics Statics is the branch of mechanics concerned with the analysisof loads (force, torque/moment) on physical systems in staticequilibrium, that is, in a state where the relative positions ofsubsystems do not vary over time, or where components andstructures are at a constant velocity. When in static equilibrium,the system is either at rest, or its center of mass moves atconstant velocity. By Newtons first law, this situation implies that the net force andnet torque (also known as moment of force) on every part of thesystem is zero. From this constraint, such quantities as stress orpressure can be derived. The net forces equaling zero is knownas the first condition for equilibrium, and the net torque equalingzero is known as the second condition for equilibrium. 4. Dynamics (mechanics) In the field of physics, the study of the causes of motion andchanges in motion is dynamics. In other words the study of forcesand why objects are in motion. Dynamics includes the study of theeffect of torques on motion. These are in contrast to kinematics, thebranch of classical mechanics that describes the motion of objectswithout consideration of the causes leading to the motion. Generally speaking, researchers involved in dynamics study how aphysical system might develop or alter over time and study thecauses of those changes. In addition, Isaac Newton established theundergirding physical laws which govern dynamics in physics. Bystudying his system of mechanics, dynamics can be understood. Inparticular dynamics is mostly related to Newtons second law ofmotion. However, all three laws of motion are taken intoconsideration, because these are interrelated in any givenobservation or experiment.[1] 5. Newtons lawsNewton described force as the ability to cause a mass to accelerate. Newtons first law states that an object in motion will stay in motionunless a force is applied. This law deals with inertia, which is aproperty of matter that resists acceleration and depends only onmass. Newtons second law states that force quantity is equal to massmultiplied by the acceleration(F = ma). Newtons third law states that for every action, there is an equal butopposite reaction. 6. Mechanical system A mechanical system manages power to accomplish a task that involves forcesand movement. Mechanical is derived from the Latin word machina,[1] which inturn derives from the Doric Greek (machana), Ionic Greek (mechane) "contrivance, machine, engine"[2] and that from (mechos),"means, expedient, remedy".[3] The Oxford English Dictionary[4] defines the adjective mechanical as skilled in thepractical application of an art or science, of the nature of a machine or machines,and relating to or caused by movement, physical forces, properties or agents suchas is dealt with by Mechanics. Similarly Merriam-Webster Dictionary[5] defines"mechanical" as relating to machinery or tools. A mechanical system consists of (i) a power source and actuators that generateforces and movement, (ii) a system of mechanisms that shape the actuator inputto achieve a specific application of output forces and movement, and (iii) acontroller with sensors that compares the output to a performance goal and thendirects the actuator input. This can be seen in Watts steam engine (see theillustration) in which the power is provided by steam expanding to drive the piston.The walking beam, coupler and crank transform the linear movement of the pistoninto rotation of the output pulley. Finally, the pulley rotation drives the flyballgovernor which controls the valve for the steam input to the piston cylinder. 7. Drilling The well is created by drilling a hole 5 to 50 inches (127.0 mm to914.4 mm) in diameter into the earth with a drilling rig that rotates adrill string with a bit attached. After the hole is drilled, sections ofsteel pipe (casing), slightly smaller in diameter than the borehole,are placed in the hole. Cement may be placed between the outsideof the casing and the borehole. The casing provides structuralintegrity to the newly drilled wellbore, in addition to isolatingpotentially dangerous high pressure zones from each other and fromthe surface. With these zones safely isolated and the formation protected by thecasing, the well can be drilled deeper (into potentially more-unstableand violent formations) with a smaller bit, and also cased with asmaller size casing. Modern wells often have two to five sets ofsubsequently smaller hole sizes drilled inside one another, eachcemented with casing. 8. To drill the well: The drill bit, aided by the weight of thick walled pipes called "drillcollars" above it, cuts into the rock. There are different types of drillbit; some cause the rock to disintegrate by compressive failure,while others shear slices off the rock as the bit turns. Drilling fluid, a.k.a. "mud", is pumped down the inside of the drill pipeand exits at the drill bit. Drilling mud is a complex mixture of fluids,solids and chemicals that must be carefully tailored to provide thecorrect physical and chemical characteristics required to safely drillthe well. Particular functions of the drilling mud include cooling thebit, lifting rock cuttings to the surface, preventing destabilisation ofthe rock in the wellbore walls and overcoming the pressure of fluidsinside the rock so that these fluids do not enter the wellbore. 9. The generated rock "cuttings" are swept up by the drilling fluid as itcirculates back to surface outside the drill pipe. The fluid then goesthrough "shakers" which strain the cuttings from the good fluid whichis returned to the pit. Watching for abnormalities in the returningcuttings and monitoring pit volume or rate of returning fluid areimperative to catch "kicks" early. A "kick" is when the formationpressure at the depth of the bit is more than the hydrostatic head ofthe mud above, which if not controlled temporarily by closing theblowout preventers and ultimately by increasing the density of thedrilling fluid would allow formation fluids and mud to come upthrough the annulus uncontrollably. The pipe or drill string to which the bit is attached is graduallylengthened as the well gets deeper by screwing in additional 30-foot(9 m) sections or "joints" of pipe under the kelly or top drive at thesurface. This process is called making a connection. Usually, jointsare combined into three joints equaling one stand. Some smallerrigs only use two joints and some rigs can handle stands of fourjoints. This process is all facilitated by a drilling rig which contains allnecessary equipment to circulate the drilling fluid, hoist and turn thepipe, control down hole, remove cuttings from the drilling fluid, andgenerate on-site power for these operations. 10. Offshore drilling Offshore drilling refers to a mechanical process where a wellboreis drilled through the seabed. It is typically carried out in order toexplore for and subsequently produce hydrocarbons which lie in rockformations beneath the seabed. Most commonly, the term is used todescribe drilling activities on the continental shelf, though the termcan also be applied to drilling in lakes, inshore waters and inlandseas. Offshore drilling presents environmental challenges, both from theproduced hydrocarbons and the materials used during the drillingoperation. There are many different types of facilities from which offshoredrilling operations take place. These include bottom founded drillingrigs (jackup barges and swamp barges), combined drilling andproduction facilities either bottom founded or floating platforms, anddeepwater mobile offshore drilling units (MODU) including semi-submersibles and drillships. These are capable of operating in waterdepths up to 10,000 ft. In shallower waters the mobile units areanchored to the seabed, however in deeper water (>5,000 ft) thesemisubmersibles or drillships are maintained at the required drillinglocation using dynamic positioning. 11. Offshore drilling program Deepwater drilling 12. Electric generator In electricity generation, an electric generator is a device thatconverts mechanical energy to electrical energy. A generator forceselectric charge (usually carried by electrons) to flow through anexternal electrical circuit. It is analogous to a water pump, whichcauses water to flow (but does not create water). The source ofmechanical energy may be a reciprocating or turbine steam engine,water falling through a turbine or waterwheel, an internal combustionengine, a wind turbine, a hand crank, compressed air or any othersource of mechanical energy. The reverse conversion of electrical energy into mechanical energyis done by an electric motor, and motors and generators have manysimilarities. Many motors can be mechanically driven to generateelectricity, and frequently make acceptable generators. 13. Engine-generator An engine-generator is the combination of an electrical generatorand an engine (prime mover) mounted together to form a singlepiece of equipment. This combination is also called an engine-generator set or a gen-set. In many contexts, the engine is taken forgranted and the combined unit is simply called a generator. 14. Gas compressor A gas compressor is a mechanical device that increases thepressure of a gas by reducing its volume. Compressors are similar to pumps: both increase the pressure on afluid and both can transport the fluid through a pipe. As gases arecompressible, the compressor also reduces the volume of a ga