05.07.2009

Core drilling involves use of a core barrel, attached at the bottom of a string of rods, which is rotated and advanced through soil or rock to obtain a core sample of the material. Water or drill fluid is used to cool the cutting bit and to carry cuttings to the surface. There are two types of core drilling: conventional and wire line. To retrieve a core cut with a conventional core barrel, the entire string of drill rods must be removed from the hole. The wire line core barrel has an inner barrel which holds the core that can be pulled up through the drill rods thereby eliminating the need to remove the entire string of drill rods

The fixed set of pulleys located at the top of the derrick or mast, over which the drilling line is threaded. The companion blocks to these pulleys are the traveling blocks. By using two sets of blocks in this fashion, great mechanical advantage is gained, enabling the use of relatively small drilling line (0.75 to 1.5 in diameter steel cable) to hoist loads many times heavier than the cable could support as a single strand

A discrete accumulation related to a localized geological structural feature and/or stratigraphic condition, typically with each accumulation bounded by a down-dip contact with an aquifer, and which is significantly affected by hydrodynamic influences, such as the buoyancy of petroleum in water.

Represents the volume of crude oil reported by petroleum refineries as being lost in their operations. These losses are due to spills, contamination, fires, etc., as opposed to refining processing losses.

The act of deepening the wellbore in order to collect a cylindrical sample taken from a formation for geological analysis. A core bit is used to accomplish this (see core bit) together with a core barrel and a core catcher

Natural gas occurring in a normal porous and permeable reservoir rock, either in the gaseous phase or dissolved in crude oil, and which technically can be produced by normal production practices.

A conventional reservoir is one that can be produced at economic flow rates and that will produce economic volumes of oil or gas without large stimulation treatment or any special recovery process. A conventional reservoir is essential a high to medium permeability reservoir in which one can drill a vertical well, perforate the pay interval and then produce the well at commercial flow rates and recover economic volumes of oil or gas