Friday, 2 August 2013

drilling techniques

Horizontal Drilling

Horizontal drilling starts with a vertical well that turns horizontal within the reservoir rock in order to expose more open hole to the oil. These horizontal "legs" can be over a mile long; the longer the exposure length, the more oil and natural gas is drained and the faster it can flow. More oil and natural gas can be produced with fewer wells and less surface disturbance. However, the technology only can be employed in certain locations.

Multilateral Drilling

Sometimes oil and natural gas reserves are located in separate layers underground. Multilateral drilling allows producers to branch out from the main well to tap reserves at different depths. This dramatically increases production from a single well and reduces the number of wells drilled on the surface.

Extended Reach Drilling

Extended Reach Drilling allows producers to reach deposits that are great distances away from the drilling rig. This can help producers tap oil and natural gas deposits under surface areas where a vertical well cannot be drilled, such as under developed or environmentally sensitive areas. Wells can now reach out over 5 miles from the surface location. Offshore, the use of extended reach drilling allows producers to reach accumulations far from offshore platforms, minimizing the number of platforms needed to produce all the oil and gas. Onshore, dozens of wells can be drilled from a single location, reducing surface impacts.

Complex Path Drilling

Complex Path Drilling creates well paths with have multiple twists and turns to try to hit multiple accumulations from a single well location. Using this technology can be more cost effective and produce less waste and surface impacts than drilling multiple
  New portable drillcat technology uses smaller portable trailer mounted rigs with shorter 10 foot (3.0 m) drill pipe. DIY users and missionary groups and even preppers use these to drill water wells as they can be operated by 1 or 2 people with a minimal skill level. The shorter drill pipe also allows a much smaller mast, which lets you have a much smaller and lighter rig which is cheaper to ship overseas and can fit in a standard 20 foot (6.1 m) shipping container. Portable trailer mounted drilling rigs have drill ratings from 300 to 800 feet (91 to 240 m) depending on mud pump flow and pressure ratings and drill pipe sizes.
Other, heavier, truck rigs are more complicated, thus requiring more skill to run. They're also more difficult to handle safely due to the longer 20 to 30 foot (6.1 to 9.1 m) drill pipe. Large truck rigs also require a much higher overhead clearance to operate. Large truck drills can use over 150 US gallons (570 L) or more of fuel per day, while the smaller Deeprock Style portable drills use a mere 5 to 20 US gallons (19 to 76 L) of fuel per day. The most desired portable rigs are USA made, because of the Steel quality. This makes smaller, more portable rigs preferable in remote or hard-to-reach places, and are more cost effective in this new era of high fuel prices. wells.

By power used

  • Mechanical — the rig uses torque converters, clutches, and transmissions powered by its own engines, often diesel
  • Electric — the major items of machinery are driven by electric motors, usually with power generated on-site using internal combustion engines
  • Hydraulic — the rig primarily uses hydraulic power
  • Pneumatic — the rig is primarily powered by pressurized air
  • Steam — the rig uses steam-powered engines and pumps (obsolete after middle of 20th Century)
  • Cable — a cable is used to raise and drop the drill bit
  • Conventional — uses metal or plastic drill pipe of varying types
  • Coil tubing — uses a giant coil of tube and a downhole drilling motor

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