To make the hole or drilling well with kelly rig, energy must be transmitted from the surface to the rock face at the end of the wellbore. Power supply for drilling has evolved from the early days of steam-driven,mechanically coupled rigs to the current standard of diesel-electric drive. In this configuration, two to four diesel engines (up to 2,000 horsepower each) drive electric generators, which supply power to individual electric motors driving the rotary table, drawworks, mua pumps, and other equipment. The rotary table is a mechanism, usually inset into the rig floor, which turns the drill string to break rock and advance the hole. (A "drill string" comprises the drill pipe plus the bottom-hole-assembly, or BHA. The BHA includes drill collars, stabilizers, bit, and any other specialized tools below the drill pipe).
Hole diameters in oil and gas drilling usually range fiom 4 to 26 inches, while geothermal holes generally have a minimum production size of 8-112 inches. To drill these holes, torque is applied to the kelly, which is at the top of the drill string. The kelly is a section of pipe with a square or hexagonal outside cross-section which engages a matching bushing in the rotary table. This bushing lets the rotary table continuously turn the kelly and drill string while they slide downward as the hole advances.
The upper end of the kelly is attached to a 'hvivel", which is a rotating pressure fitting that allows the drilling fluid to flow fiom the mud pumps, up the standpipe, through the kelly hose, into the swivel, and finally down the drill pipe as it rotates. The swivel is carried by the hook on the traveling block and it suspends most of the weight of the drill string while drilling.
Moving the drill string or the casing into and out of the hole is called tripping. Trips are usually required because the bit or some other piece of downhole equipment must be replaced, or because of some activity such as logging, testing, or running casing, and of course trips take longer as the hole grows deeper. Raising or lowering the drill string for a trip is done by the drawworks, which is basically a large winch. (The swivel and kelly are almost always handled as a unit, and are set aside in the "rat hole" while tripping.) The drawworks reels in or pays out a wire rope (drilling line) which passes over the crown block at the top of the rig's mast and then down to the traveling block which carries the hook, which in turn suspends the drill string or casing. Depending on what mechanical advantage is required, the drilling line is reeved several times between the crown and traveling blocks, as in a block and tackle.
Geothermal energy presents a unique opportunity to reduce reliance on fossil fuels and combat climate change. By tapping into the Earth's heat, we can generate clean, renewable energy with minimal environmental impact. It's inspiring to see companies like GTD Desco at the forefront, driving the industry forward and shaping a greener, more sustainable future for generations to come. As we continue to invest in geothermal drilling rig , we move closer to achieving our goals of a cleaner, more sustainable energy landscape.
ReplyDeleteGeothermal drilling with a Kelly rig opens up a world of possibilities for sustainable energy solutions. These rigs, specifically designed for geothermal applications, offer unparalleled efficiency and precision in harnessing Earth's natural heat. As a leading provider in the field, we've seen firsthand the transformative power of geothermal drilling rigs. From reducing carbon footprints to providing reliable renewable energy, these rigs are paving the way towards a greener future.
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