In the oil and gas industry, the process of beginning to drill a well. Initially a larger drill bit is used to drill a surface hole, which is lined with casing and cement to protect groundwater. After the surface hole is completed, the main drill bit is inserted and the well is drilled to the total depth.

Can also be referred to as "spudding in".


Drilling for oil and gas is a highly complex task involving sophisticated techniques and machinery. It often costs hundreds of thousands of dollars to drill even a simple well. More difficult wells can cost millions of dollars. The most expensive wells are often found offshore, where high-end drilling platforms can cost over $500,000 per day in times of peak demand.

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  1. How much oil must be produced to maintain inventory levels in the United States?

    Domestic energy investors should track the reserve inventory of crude oil for the United States, which is released in a weekly ... Read Full Answer >>
  2. To what extent is the oil and gas sector dominated by a few major companies?

    Oil and gas are two expansive and highly diverse product lines, with active competition domestically and internationally. ... Read Full Answer >>
  3. What factors are the primary drivers of share prices in the oil and gas sector?

    The primary drivers of share prices in the oil and gas sector are energy prices and economic growth. Stock prices in the ... Read Full Answer >>
  4. What impact does the growth in horizontal drilling have in the oil and gas sector?

    It is tough to separate the growth in horizontal drilling from the growth in hydraulic fracturing, or fracking; the two techniques ... Read Full Answer >>
  5. What are the main substitutes for oil and gas energy?

    The main substitutes for oil and gas energy include nuclear power, solar power, ethanol and wind power. Fossil fuels dwarf ... Read Full Answer >>
  6. How much of the United States' energy comes from oil and gas?

    As of 2014, the oil and gas sector accounted for approximately 50% of total U.S. energy needs, with approximately another ... Read Full Answer >>

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