Oil and Gas Well Drilling and Servicing eTool
† This is an abridged version of the Dictionary of Petroleum Terms provided by Petex and the University of Texas Austin. © Petex 2001
n: the end of the drilling line that is affixed to the drum or reel of the drawworks, so called because it travels with greater velocity than any other portion of the line. Compare deadline.
n: a rack that supports the stands of pipe being stacked in the derrick or mast. It has several steel fingerlike projections that form a series of slots into which the derrickman can place a stand of drill pipe or collars after it is pulled out of the hole and removed from the drill string.
n: a thermal recovery method in which the oil in the reservoir is ignited, the heat vaporizes lighter hydrocarbons and water pushes the warmed oil toward a producing well. Also called in situ combustion. See thermal recovery.
n: an object that is left in the wellbore during drilling or workover operations and that must be recovered before work can proceed. It can be anything from a piece of scrap metal to a part of the drill stem.
n: the procedure of recovering lost or stuck equipment in the wellbore.
n: a powerful magnet designed to recover metallic objects lost in a well.
n: a tool designed to recover equipment lost in a well.
n: the person (usually a service company employee) in charge of directing fishing operations.
n: a small, often standardized, part (such as a coupling, valve, or gauge) installed in a larger apparatus.
n: a special coupling device inserted one or two joints above the bottom of the casing string that contains a check valve to permit fluid to pass downward but not upward through the casing. The float collar prevents drilling mud from entering the casing while it is being lowered, allowing the casing to float during its descent and thus decreasing the load on the derrick or mast.
n: a short, heavy, cylindrical steel section with a rounded bottom that is attached to the bottom of the casing string. It contains a check valve and functions similarly to the float collar but also serves as a guide shoe for the casing.
v: 1. to drive oil from a reservoir into a well by injecting water under pressure into the reservoir formation. See waterflooding. 2. to drown out a well with water.
n: a current or stream of fluid or gas.
n: those workers on a drilling or workover rig who work primarily on the rig floor. See rotary helper.
n: see rotary helper.
n: see rotary helper.
n: a well that produces oil or gas by its own reservoir pressure rather than by use of artificial means (such as pumps).
n: the surface pipe through which oil or gas travels from a well to processing equipment or to storage.
n: the speed, or velocity, of fluid or gas flow through a pipe or vessel.
n: injection of gases or liquids into a reservoir to force oil toward and into producing wells.
n: the unwanted migration of the liquid part of the drilling mud or cement slurry into a formation, often minimized or prevented by the blending of additives with the mud or cement.
n: fluid (such as gas, oil, or water) that exists in a subsurface formation.
n: gas initially produced from an underground reservoir.
n: the force exerted by fluids or gas in a formation, recorded in the hole at the level of the formation with the well shut in. Also called reservoir pressure or shut-in bottomhole pressure.
n: the gathering of pressure data and fluid samples from a formation to determine its production potential before choosing a completion method.
n: 1. the water originally in place in a formation. 2. any water that resides in the pore spaces of a formation.
n: a fluid used in the fracturing process (for example, a method of stimulating production by opening new flow channels in the formation surrounding a production well). Under extremely high hydraulic pressure, frac fluids (such as distillate, diesel fuel, crude oil, dilute hydrochloric acid, water, or kerosene) are pumped downward through production tubing or drill pipe and forced out below a packer or between two packers. The pressure causes cracks to open in the formation, and the fluid penetrates the formation through the cracks. Sand grains, aluminum pellets, walnut shells, or similar materials (propping agents) are carried in suspension by the fluid into the cracks. When the pressure is released at the surface, the fracturing fluid returns to the well but leaves behind the propping agents to hold open the formation cracks.
n pl: fuel storage tanks for the power generating system.
n: a crack or crevice in a formation,either natural or induced. See hydraulic fracturing.
n: a procedure by which acid is forced into a formation under pressure high enough to cause the formation to crack. The acid acts on certain kinds of formations, usually carbonates, to increase the permeability of the formation. Also called acid fracturing.
n: the pressure at which a formation will break down, or fracture.
n: a fluid, such as water, oil, or acid, used in hydraulic fracturing. The fluid carries propping agents that hold open the formation cracks after hydraulic pressure dissipates. See acid fracturing, hydraulic fracturing, propping agents.
n: a device run on wireline into the wellbore and inside the fishing string and fish to locate the area where a fish is stuck. When the drill string is pulled and turned, the electromagnetic fields of free pipe and stuck pipe differ. The free-point indicator is able to distinguish these differences, which are registered on a metering device at the surface.
n: resistance to movement created when two surfaces are in contact. When friction is present, movement between the surfaces produces heat.
n: a bit that has maintained its original diameter.
n: a wellbore drilled with a full-gauge bit. Also called a true-to-gauge hole.