Oil & Gas Glossary 1.0

The ratio between the pressure required to open the preventer and the well pressure under the rams.

The ratio between the pressure in the hole and the operating-piston pressure needed to close the rams of a blowout preventer.

Gas-liquid-ratio

An opening at floor level in a side of a derrick or mast. The V-door is opposite the drawworks and is used as an entry to bring in drill pipe, casing, and other tools from the pipe rack. The name comes from the fact that on the old standard derrick, the shape of the opening was an inverted V.

A device placed in a choke line that regulates the flow through the choke. Flow depends on the size of the opening in the bean; the larger the opening, the greater the flow.

The ratio of the actual volume of gas at a given temperature and pressure to the volume of gas when calculated by the ideal gas law.

A measure of the volume of gas produced with oil, expressed in cubic feet per barrel of cubic meters per tonne.

An opening into a tank, usually through the top deck.

To pass (as a rope) through a hole or opening in a block or similar device.

2. a hole or opening in a line or vessel into which a gauge or valve may be inserted and screwed tight.

2. the ratio of the mass of a given volume of a substance to the mass of a like volume of a standard substance, such as water or air.

An opening or space within a rock or mass of rocks, usually small and often filled with some fluid (water, oil, gas, or all three). Compare vug.

A drillable tool configuration allowing the opening of formation pressure, during drillout, prior to cutting through the tools slips.

2. a removable lining or sleeve inserted or screwed into an opening to limit its size, resist wear or corrosion, or serve as a guide.

Density expressed as the ratio of the weight of a volume of substance to the weight of an equal volume of another standard substance. In the case of liquids and solids, the standard is water. In the case of natural gas or other gas materials, the standard is air.

A device with a restricted opening placed in the lower end of the tubing to control the rate of flow. See choke.

Operates on the same principle as an annular valve, except it requires pipe rotation for opening and closing operations.

A rubber plug used in primary cementing operations to displace cement slurry from the casing into the borehole annulus.

In a well-control operation, closing the BOP without first opening an alternate flow path up the choke line. When the BOP is closed, pressure in the annulus cannot be read on the casing pressure gauge.

A small swivel hook having a fast-operating automatic latch to close the hook opening when weight is suspended from the hook.

A heavy-duty steel, T-shaped pipe fitting that is screwed or flanged to the top of a pumping well. The polished rod works through a stuffing box on top of the tee and in the run of the tee to operate a sucker rod pump in the well. Pumped fluid is discharged through the side opening of the tee.

The ratio of effective permeability to absolute permeability. The relative permeability of rock to a single fluid is 1.0 when only that fluid is present, and 0.0 when the presence of another fluid prevents all flow of the given fluid. Compare absolute permeability, effective permeability.

A device to provide running the tubing dry with a packer released by elevating tubing pressure, thereby opening the tubing to formation pressure.

An essentially full-opening valve installed immediately below the kelly, with outside diameter equal to the tool joint outside diameter.

An essentially full-opening valve installed immediately below the kelly, with outside diameter equal to the tool joint outside diameter.

A measure of fineness of a woven material, screen, or sieve; e.g., a 200-mesh sieve has 200 openings per linear inch. A 200-mesh screen with a wire diameter of 0.0021 in. (0.0533 mm) has an opening of 0.074 mm, or will pass a particle of 74 microns. See micron.

A special device that, when fitted in to the master bushing, transmits torque to the kelly and simultaneously permits vertical movement of the kelly to make hole. It may be shaped to fit the rotary opening or have pins for transmitting torque. Also called

The principal component of a rotary, or rotary machine, used to turn the drill stem and support the drilling assembly. It has a beveled gear arrangement to create the rotational motion and an opening into which bushings are fitted to drive and support the drilling assembly.

An opening of a measured diameter that is used for measuring the flow of fluid through a pipe, the orifice must be of smaller diameter than the pipe diameter. It is drilled into an orifice plate held by an orifice fitting.

1. the ratio of the weight of a given volume of a substance at a given temperature to the weight of an equal volume of a standard substance at the same temperature. For example, if 1 cubic inch of water at 39 degrees F weighs 1 unit and 1 cubic inch of another solid or liquid at 39 degrees F weight 0.95 unit, then the relative density of the substance is 0.95. In determining the relative density of gases, the comparison is made with the standard of air or hydrogen.

A device that stores hydraulic fluid under pressure in special containers and provides a method to open and close the blowout preventers quickly and reliably. Usually, compressed air and hydraulic pressure provide the opening and closing force in the unit. See blowout preventer.

A tubular, perforated device attached to the bottom of sucker-rod pump that helps to prevent gas lock. The device works on the principle that gas, being lighter than oil, rises. As well fluids enter the anchor, the gas breaks out of the fluid and exits from the anchor through perforations near the top. The remaining fluids enter the pump through a mosquito bill (a tube with the anchor), which has an opening near the bottom. In this way, all or most of the gas escapes before the fluids enter the pump.

A method of stimulating production by opening new flow channels in the rock surrounding a production well. Often call a frac job. Under extremely high hydraulic pressure, a fluid (such as distillate, diesel fuel, crude oil, dilute hydrochloric acid, water, or kerosene) is 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. The cracks partially close on the pellets, leaving channels for oil to flow around them to the well. See explosive fracturing, hydraulic fracturing.