- Settore: Oil & gas
- Number of terms: 8814
- Number of blossaries: 0
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An oil mud designed and maintained with a minimum of colloid-sized solids, typically by omitting fatty-acid soap and lime, and minimizing organophilic clays and fluid-loss additives. Low-colloid oil mud, also called a relaxed filtrate oil mud, increases drilling rate. A disadvantage is that filter cake formed on sands is not tight, can quickly become very thick, and can cause pipe to stick by differential pressure.
Industry:Oil & gas
An item of solids-control equipment consisting of an inverted cone, the mud being fed tangentially into the upper (larger diameter) part. The resulting spinning effect forces solids to the wall of the device and they exit from the bottom (apex) of the cone, while the cleaned liquid exits at the top. Hydrocyclones are classified by the size of the cone as either desanders (typically 12 inches in diameter) or desilters (4 to 6 inches in diameter) and will separate particles in the medium-, fine- and ultrafine-size ranges. The efficiency of hydrocyclones is poor in viscous weighted muds and many units are being replaced by more efficient, high-speed shakers.
Industry:Oil & gas
An isolation device that relies on elastomers to expand and form an annular seal when immersed in certain wellbore fluids. The elastomers used in these packers are either oil- or water-sensitive. Their expansion rates and pressure ratings are affected by a variety of factors. Oil-activated elastomers, which work on the principle of absorption and dissolution, are affected by fluid temperature as well as the concentration and specific gravity of hydrocarbons in a fluid. Water-activated elastomers are typically affected by water temperature and salinity. This type of elastomer works on the principle of osmosis, which allows movement of water particles across a semi-permeable membrane based on salinity differences in the water on either side of the membrane.
Industry:Oil & gas
An invert-emulsion mud, or an emulsion whose continuous phase is oil. In the past, the term referred to an oil mud containing less than about 5 vol. % water. This definition, at the time, distinguished mud with less than 5 vol. % water from invert-emulsion oil muds, which had more than 5 vol. % water. Today, this distinction is not practical because most commercial oil muds can be formulated with more or less than 5 vol. % water using essentially the same types of products.
Industry:Oil & gas
An inverted "U" shaped section of rigid piping normally used as a conduit for high-pressure drilling fluid. In particular, the term is applied to a structure that connects the top of a vertical standpipe running up the side of a derrick or mast to a flexible kelly hose that in turn is connected to another gooseneck between the flexible line and the swivel.
Industry:Oil & gas
An integral bit and eccentric reamer used to simultaneously drill and underream the hole.
Industry:Oil & gas
An instrument used for quantitative analyses of sulfides and carbonates. Specific test methods have been published by API. The oil-mud procedure analyzes active sulfides and uses whole mud samples, whereas the water-base drilling fluid procedure tests filtrate. The GGT unit is a clear, plastic block (2. 5 in. X 4 in. X 6 in. ) that contains three interconnected chambers. A carrier gas is used to flow an inert gas through the chambers. The sample is placed in chamber #1 and is acidified to release sulfides as H<sub>2</sub>S and carbonates as CO<sub>2</sub>. The appropriate Drdger tube is used to measure the effluent gas that is evolved from the sample. The device is named after Bob Garrett, who invented it while at Exxon Production Research. <br><br>Reference:<br>Garrett RL: "A New Field Method for the Quantitative Determination of Sulfides in Water-Based Drilling Fluids," Journal of Petroleum Technology 29, no. 9 (September 1977): 1195-1201. <br><br>Garrett RL: "A New Field Method for the Quantitative Determination of Carbonates in Water-Base Drilling Fluids," Journal of Petroleum Technology 30, no. 7 (July 1978): 860-868. <br><br>Garrett RL, Carlton LA and Denekas MO: "Methods for Field Monitoring of Oil-Based Drilling Fluids for Hydrogen Sulfide and Water Intrusions," SPE Drilling Engineering 3, no. 3 (September 1988): 296-302.
Industry:Oil & gas
An influx of formation water, usually salty and sometimes hard, into the mud in the wellbore. Saltwater flows contaminate freshwater or seawater muds, making it expensive, difficult and time-consuming to regain the mud properties. Influxes pose a lesser problem for saltwater muds. Saltwater contamination flocculates the bentonite clay in fresh- or seawater muds. Flocculated, thick, filter cake on a permeable zone frequently results in differential-pressure sticking.
Industry:Oil & gas
An instrument for measuring the viscosity of a fluid by passing the fluid at a known pressure gradient or velocity through a length of tubing of known diameter. The viscosity of base oils for oil muds, which are Newtonian fluids, is measured using a glass capillary tube in a thermostatic bath, when performed according to API procedures.
Industry:Oil & gas
An individual trained in the science and art of intentionally drilling a well along a predetermined path in three-dimensional space, usually involving deviating the well from vertical and directing it in a specific compass direction or heading. The directional driller considers such parameters as rotary speed, weight on bit, control drilling and when to stop drilling and take surveys of the wellpath, and works closely with the toolpusher.
Industry:Oil & gas
