For the sake of authenticity, many oilfield terms found their way into the novel Fog Over Mandaree. These definitions ought to help clarify terms.
Note: this is not intended to be a technical glossary, nor is it by any means complete. Regardless, if we missed any jargon found in the book, please let us know.
| Term | Definition |
| air hoist or air chugger | A hoist operated by compressed air; a pneumatic hoist. Air hoists are often mounted on the rig floor and are used to lift joints of pipe and other heavy objects. |
| annulus | The space between two concentric circles. In the oil industry, it is usually the space surrounding a pipe in the wellbore, or the space between tubing and casing, or the space between drill pipe and the wellbore. Drilling fluid and cuttings circulate up from the drill bit to the surface through the annulus. |
| barite | Barium sulfate (BaSO⁴); a dense mineral frequently used to increase the weight or density of drilling mud. |
| BHA | Bottomhole assembly. This usually includes the drill bit, downhole mud motor, Measurement While Drilling (MWD) tools, and stabilizers. |
| blowout preventer | Also known as the BOP. One of the several valves installed at the wellhead to prevent the escape of fluids either in the annular space between the casing and the drill pipe or in the open hole (a wellbore with no drill pipe) during drilling or completion operations. |
| Citra-Solv | A powerful detergent that Mudloggers use for cleaning drilling fluid off drill cuttings (samples) to identify the formation. Its strong aroma resembles citrus fruit. |
| command center | The working shack which is occupied by Directional Drillers, MWD personnel and Mudloggers. |
| Company Man | Also known as company representative. An employee or contracted consultant of an operating company whose job is to represent the company’s interests at the drilling location. |
| cuttings, drill cuttings | The fragments of rock broken by the bit and circulated up to the surface in the drilling fluid. |
| Derrickhand | The drilling rig crewmember who works in the derrick on the monkeyboard and handles the upper end of the drill string as it is being hoisted out of or lowered into the hole. This person is also responsible for the circulating machinery and the conditioning of the drilling fluid. |
| doghouse | A small enclosure on the rig floor used as an office for the driller and as a storehouse for small objects. |
| drill bit | Also known as bit. The cutting or boring element used for drilling. |
| Driller | The employee directly in charge of a drilling rig and crew whose main duty is operation of the drilling and hoisting equipment. The driller is also responsible for the condition of the well and the supervision of the drilling crew. The driller is directly subordinate to the Toolpusher and indirectly to the Company Man. |
| drilling fluid, drilling mud | Circulating fluid, one function of which is to lift cuttings out of the wellbore and to the surface. Other functions are to cool and lubricate the bit and the drill string and to offset downhole formation pressures. Drilling fluids in most situations in North Dakota consist of three stages: first, freshwater for surface drilling through upper water-bearing formations; then diesel-based invert through the remainder of the vertical and curve portion of the well; finally, saltwater throughout the lateral portion of the well (though sometimes diesel-based fluid is used here, too, if conditions justify the expense). |
| drill pipe | Jointed steel pipe made up in the drill step between the kelly or top drive on the surface and the bottomhole assembly on the bottom. Joints are made up (screwed together) to form the drill string. |
| drill string | The column, or string, of drill pipe with attached tools that transmits fluid and rotational power from the kelly to the bit. Compare drill stem. |
| evening tour | The work shift of a drilling crew that starts in the evening or night. Drilling operations usually occur around the clock because of the daily cost to rent a rig. As a result, there are usually two separate crews working twelve-hour tours to keep the operation going. Note that “tour” in this context is pronounced “tower” among those in the oil industry. |
| flock tank | Also spelled “floc” for “flocculant chemical”. These are large, open tanks, usually used for settling solids from fluids or oils from other drilling fluid. |
| Floor Hand | Worker on a drilling or workover rig, subordinate to the driller and the derrickhand, whose primary work station is on the rig floor. Also called a, floorman, rig crewman, or roughneck. |
| fluoroscope | An enclosed instrument used for observing oil shows in drill cuttings. Mudloggers and geologists use this tool in conjunction with an industrial solvent such as trichloroethylene or butane to coax oil from source rock. |
| hopper, hopper house | The component on a drilling rig used to facilitate the addition of drilling fluid additives to the whole mud system. A hopper is generally used to introduce relatively small quantities of additives in the mud system. This work station is usually overseen by a derrick hand. |
| joint | A single length (from 16 feet to 45 feet, but usually averaging 29-33 feet) of drill pipe, drill collar, casing, or tubing that has threaded connections at both ends. Multiple joints of point together form a drill string. |
| location | The place where a well is being drilled. Also called well site. |
| manifold | An accessory system of piping to a main piping system (or another conductor) that serves to divide a flow into several parts, to combine several flows into one, or to reroute a flow to any one of several possible destinations |
| monkeyboard | The derrick hand’s working platform at the correct height in the derrick for handling the top of the pipe. As pipe is run into or out of the hole, the derrick hand must handle the top end of the pipe (90 feet or higher in the derrick or mast) |
| morning tour | The work shift of a drilling crew that starts in the morning. Note that “tour” in this context is pronounced “tower” among those in the oil industry. |
| Motor Hand | Also known as motorman. The member of the rig crew responsible for maintenance of the engines. While all members of the rig crew help with major repairs, the motorhand does routine preventive maintenance and minor repairs. |
| Mudlogger | An employee of a mud logging company who performs mud logging. Primary responsibility includes collection, analyzing, and recording of drill cutting samples into a digital Mud Log. |
| pipe ram | A sealing component for a blowout preventer that closes the annular space between the pipe and the blowout preventer or wellhead. |
| premix | A premix tank is a component of a drilling rig used by the derrickhand to mix special, small batches of drilling fluid recipes to be introduced on demand into the active mud system. |
| pull out of hole | Also known as POOH or TOOH (trip out of hole). To remove the drillstring from the wellbore. |
| reserve pit | An artificial settling pond located on the back side of a drilling rig, used to collect drilling fluids and drill cuttings to be later disposed of. At the time of Fog Over Mandaree, every rig in North Dakota had a reserve pit. Current practices have evolved to a more environmentally-conscious closed system, where fluids are separated from solids via centrifuge and stored in enclosed tanks. Waste material is trucked off to purpose-built landfills rather than stored permanently on site, as used to be common practice. |
| Rig Hand | A crew member who is part of a drilling crew, commonly referred to as a roughneck. See driller, derrickhand, motorhand, floorhand. |
| ROP | Rate of penetration. A measure of the speed at which the bit drills into formations, usually expressed in feet (or metres) per hour or minutes per foot (metre). |
| roughneck | See rig hand. |
| running off | Also known as being run off. To be suddenly dismissed or fired from the job, usually with cause. |
| sample | The well cuttings obtained at the designated footage intervals during drilling. From an examination of these cuttings, the geologist determines the type of rock and formations being drilled and estimates oil and gas content. |
| shaker screens | The actual screen on a shaker. |
| shakers | Shortened form of shale shaker. A vibrating screen used to remove cuttings from the circulating fluid in rotary drilling operations. The size of the openings in the screen should be carefully selected to be the smallest size possible to allow 100 percent flow of the fluid through the screen. |
| skid shack | sometimes referred to as “camp” by rig hands |
| slug or pill | Also called A volume of mud that is more dense than the mud in the drillpipe and wellbore annulus. A slug is used to displace mud out of the upper part of the drillpipe before pulling pipe out of the hole and is mixed in the pill pit by adding additional weighting material (barite) to a few barrels of mud from the surface pits or premix tank. The pill is pumped into the top of the drillstring to push mud downward, out of the pipe, thus keeping the upper stands of pipe empty. Standard practice before tripping pipe out of hole is to pump a slug/pill downhole to force the drilling fluid and gasses to remain trapped and not follow the drill string back uphole. |
| stand | The connected joints of pipe racked in the derrick or mast when making a trip. On a rig, the usual stand is about 90 feet long. |
| Toolpusher | An employee of a drilling contractor who is in charge of the entire drilling rig. Also called a drilling foreman, rig manager, rig superintendent, or rig supervisor. Each rig has one or sometimes two Toolpushers on location at all times. |
| tour | A working shift for drilling crew or other oilfield workers. On rigs where a tour is 8 hours, they are called daylight, afternoon (or evening), and morning. Usually 12-hour tours are used, where they are simply morning/day tour and evening/night tour. Note that “tour” in this context is pronounced “tower” among those in the oil industry. |
| trichloroethylene | A clear, sweet-smelling chemical compound used as an industrial solvent. Used in the oilfield by mudloggers, in conjunction with fluoroscopes, to extract oil from drill cutting samples. This deceptively innocuous chemical has been associated with carcinogenic and neurological effects. |
| tripping pipe | The act of pulling the drillstring out of the hole (Tripping Out of Hole or TOH), or replacing it in the hole (Tripping In Hole or TIH). A pipe trip is usually done because the bit has dulled or has otherwise ceased to drill efficiently and must be replaced, or when the well has reached its target depth. |
| washout | An enlarged region of a wellbore or within a drill pipe or bottomhole assembly itself. Washouts within a wellbore are common as drilling progresses, while washouts in drill pipe or the BHA are uncommon and undesirable. Generally speaking, washouts become more severe with time. Appropriate mud types, mud additives and increased mud density can minimize washouts. |
| well head | The equipment installed at the surface of the wellbore. |
| well pad | A patch of land where a well is located. |
| Wellsite Geologist | In the oilfield, the roles of the wellsite geologist and mudlogger are often blurred and accomplished by the same individual. Strictly speaking, a mudlogger contends with collecting, washing, and analyzing drill cutting samples, while a wellsite geologist interprets formation and assigns targets. Throughout their careers in the oilfield, Frank and RaeLea performed both duties. |
| worm | A new, completely inexperienced member of the drilling crew. Such a crewmember is stereotyped as prone to making mistakes and being injured, and typically endures pranks played on him by the drilling crew. |