in the previous post, we discussed so many oilfield terms, and we will continue in this post the rest of these important terms used in oilfield.
BLOWOUT PREVENTER, RAM TYPE – A device designed to form a seal on the hole with no pipe or in the annular space with pipe in the hole. The equipment can use pipe rams, blind rams, or blind/shear/cutter rams to affect the required seal, according to equipment availability, arrangement of the equipment, and/or existing well conditions. Pipe rams have ends contoured to seal around pipe to close and seal the annular space. Blind rams have ends not intended to seal against any tubulars, rather they seal against each other to effectively close and seal the wellbore. Blind/shear/cutter rams are blind rams equipped with a built-in cutting edge that will shear tubulars that may be in the hole, thus allowing the blind rams to close against each other and seal the wellbore.
BOPD – Barrels of oil per day
BOREHOLE- The wellbore; the hole made by drilling or boring a well.
BOTTOM CASING PACKOFF – A mechanism that seals off annular pressure between the OD of a suspended tubular member or hanger and the ID of the spool or tubing head adapter being placed over the suspended tubular or hanger.
BOTTOM FLOODING – The behavior of a hydrocyclone when the underflow discharges in a liquid stream.
BOTTOM-HOLE – The lowest or deepest part of a borehole.
BOTTOM-HOLE ASSEMBLY – Assembly composed of the bit, stabilizers, reamers, drill collars, subs, etc., used at the bottom of the drill string. Sometimes abbreviated as BHA.
BOTTOM-HOLE BACK TORQUE – Torque on the drill stem causing a twisting of the string.
BOTTOM HOLE CHOKE – A device with a restricted opening placed in the lower end of the tubing to control the rate of liquid or gas flow to the surface.
BOTTOM HOLE PRESSURE – Pressure in a wellbore at the depth of the producing interval. Usually recorded by gage run on wire line.
BS&W – Basic sediment and water. Water and other foreign matter in crude oil produced. This must be reduced to a very small percentage before delivering to crude purchaser.
BTU (BRITISH THERMAL UNIT) – A measure of the heating value of a fuel.
BUBBLE CAP – A metal cap designed with openings to cause the upward-flowing gas “bubbles” in a gas-processing tower to intimately contact downward-flowing liquids, causing some of the gas to condense to liquid. Bubble caps are mounted on a perforated-steel BUBBLECAP TRAY.
BUBBLE POINT – The state of a liquid-phase system when it is in equilibrium with an infinitesimal amount of vapor phase.
BUBBLE-POINT PRESSURE – The fluid pressure in a system at its bubble point. (Often used
interchangeably with “saturation pressure.”)
BYPASS – Usually refers to a pipe connection around a valve or other control mechanism. A bypass is installed in such cases to permit passage of fluid through the bypass line while adjustments or repairs are made on the control which is bypassed.
CAPITAL INVESTMENT – Funds spent to acquire additions to assets for the betterment of the operation. Depreciation is taken on such expenditures rather than charging them off as expense or operating cost.
CARBON DIOXIDE (CO2) – A colorless, odorless, nonpoisonous gas that is a normal part of the ambient air. Dissolved in the aqueous phase of drilling fluids, C02 may contribute to corrosivity of these fluids or to unstable rheological properties.
CASED HOLE – A wellbore in which casing has been run.
OR Pipe used in wells to seal off the borehole.
OR Steel pipe used in oil wells to seal off fluids from the bore hole and to prevent the walls of the hole form sloughing off or caving. API casing sizes range from 4 ½ in. OD to 20 in. OD inclusive.
OR Pipe installed in the wellbore and usually cemented in place to retain the borehole dimension and seal off hydrocarbon and water-bearing formations.
OR Steel pipe placed in an oil or gas well as drilling progresses. The function of casing is to prevent the wall of the hole from caving during drilling, provide control of the well if it tries to blow out, and limit oil or gas production to the zone perforated or open.
CASING HANGERS (SLIPS) – A mechanism used to support a casing string in a casing head by gripping the pipe with wedge type members.
CASING HANGERS, THREADED (MANDREL) – A mechanism used to support a casing string in a casing head by means of a male or female thread attached to the casing.
CASING HEAD HOUSING – Equipment attached to the uppermost end of the surface casing
which serves to suspend and seal a casing string.
CASING HEAD SPOOL – Equipment attached to another casing head which serves to suspend and seal a secondary casing string.
CASING STRING – The pipe run in a well, for example: surface string, intermediate string, production string, etc.
CASING HEAD – A heavy, steel, flanged fitting that connects to the surface string of casing and provides a housing for the slips and packing assemblies by which intermediate strings of casing are suspended and the annulus sealed off.
CAST IRON – An alloy of iron and about 2 to 4 percent carbon.
A. Grey cast iron: The graphite (carbon) is present as flakes. This makes a fracture appear grey.
B. White cast iron: The carbon is present as carbides. With no graphite to color it, a fracture appears metallic white.
CELLAR – A hole dug, usually before drilling a deep well, to allow working space for the casinghead equipment.
OR Excavation around the wellhead to provide space for items of equipment at the top of the wellbore. It also serves as a pit to collect drainage of water and other liquids.
API Classes – Cement (Classes A through J) meeting the applicable requirements of API Spec 10.
ASTM Types – Cement (Types I through V) meeting the applicable requirements of Standard Specifications for Portland Cement ASTM C150.
Common, Regular or Ordinary – A cement intended for use under conditions not requiring moderate to high sulfate resistance. Corresponds to API Class A or Class C which are similar to ASTM Type I or Type III cements, respectively.
Gel Cement – A cement or cement slurry that has been modified by the addition of bentonite.
Gypsum Cement – Composed primarily of the hemihydrate form of calcium sulfate, CaSO4 – 1/2H20 (Plaster of Paris)
High Temperature – A cement designed to overcome strength retrogression within the temperature limits designated by the supplier.
Hydraulic Cement – A cement that sets and hardens by chemical interaction with water and that is capable of doing so under water.
Modified Cement – A cement whose properties, chemical or physical, have been altered by additives. This term has been used to refer to specific formulations of gel cement containing certain concentrations of dispersing agent.
Neat – A cement paste or slurry containing no additives.
Well – Cement or mixture of cement with other materials that is intended for us in oil, gas, geothermal or water wells.
Portland – Hydraulic cement produced by pulverizing clinkers consisting essentially of hydraulic calcium silicates and usually containing one or more of the forms of calcium sulfate as an interground addition.
Portland-Blast Furnace Slag – An intimate and uniform blend of Portland cement (or clinker) and fine granulated blast furnace slag in which the amount of slag is within specified limits.
Portland-Pozzolan – A hydraulic cement consisting of an intimate and uniform blend of Portland cement or portland blast furnace slag cement and fine pozzolan produced by intergrinding portland cement clinker and pozzolan, by blending portland cement or portland blast furnace slag cement and finely divided pozzolan, or a combination of intergrinding and blending, in which the amount of the pozzolan constituent is within specified limits.
Retarded Cement – A cement in which the thickening time is extended by adding a chemical retarder.
Slow-Set Cement – A cement in which the thickening time is extended by (1) eliminating the rapid hydrating components in its composition or (2) by adding a chemical retarder. API Classes D, E, and F are slow-set cements.
Suflate-Resistant Cement – Cements which meet applicable requirements of API Spec 10.
Weighted Cement – A cement slurry containing additives to increase its normal density.
CEMENTING – The process of pumping a cementitious slurry into a well through steel pipe to critical points in the annulus or open hole. Cementing is performed to isolate different zones in the well, protect the pipe from corrosive fluids, support the pipe in the hole, or repair previous cement jobs.
CEMENTING TIME – The total elapsed time for a cementing operation from the beginning of mixing until the completion of displacement to final depth and complete circulation of any excess slurry to the surface.
CENTIPOISE (CP) – A unit of viscosity equal to 0.01 poise. A poise equals 1 g per metersecond, and a centipoise is 1 g per centimeter-second. The viscosity of water at 20C is 1.005 cp (1 cp = 0.000672 lb/ft-sec).
CENTRIFUGAL SEPARATOR – A general term applicable to any device using centrifugal force to shorten and/or to control the settling time required to separate a heavier mass from a lighter mass.
CHECK VALVE – A valve that permits flow in one directly only.
CHOKE – A type of orifice installed in a line to restrict flow and control the rate of production. Surface chokes are a part of the “Christmas tree” and contain a choke nipple, or bean, with a small-diameter bore (an orifice) that serves to restrict the flow. Also, chokes are used to control the rate of flow of the drilling mud out of the hole when the well is closed in with the blowout preventer and a “kick” is being circulated out of the hole.
CHRISTMAS TREE – A term applied to the control valves, pressure gages, and chokes assembled at the top of a well to control the flow of oil and gas.
OR The assembly of valves, pipes, and fitting used to control flow of oil and gas from the well.
OR Term applied to the valves and fittings assembled at the top of a completed well to control the flow of hydrocarbons and other fluids.
OR A term applied to the valves and fittings assembled above and starting at the top of the tubing spool on a completed well to control the flow of hydrocarbons and other fluids.
OR An assembly of valves and fittings attached to the uppermost flange of the tubing head, used to control well production.
OR The valves, pressure gages, and chokes assembled at the top of a well to control the flow of oil and gas after the well has been completed.
COMBUSTION – The chemical reaction of rapid oxidation which is accompanied by the emission of light and heat – the flame. Combustion begins when the temperature of the ignitable substance reaches its apparent ignition temperature. This process will be self-sustaining as long as the heat released in combustion maintains the temperature with the flammable range of the ignitable substance.
COMPRESSOR – A rotating or reciprocating machine, together with its driver and associated scrubbers, coolers, pipe, valves, controls, etc., used to compress gas or air from a lower to a higher pressure.
CONDENSATE – A liquid formed by condensation from a vapor phase. Within the reservoir, “condensate” is a liquid-hydrocarbon phase formed by retrograde condensation from the vapor phase upon pressure reduction. At the surface, “condensate” is a liquid-hydrocarbon phase formed by condensation form the vapor phase upon pressure and/or temperature reduction.
CONNATE WATER – Formation water locked in the pores of a formation by capillary action. This water does not flow without introducing strong driving forces or by means of a chemical reaction.
CONTAINMENT – Any method used on an offshore platform to collect and direct escaped liquid hydrocarbons to a safe location.
Resources:
1. Glossary of Oilfield Production Terminology.
2. Glossary of Oilfield Terms.
