- Settore: Oil & gas
- Number of terms: 8814
- Number of blossaries: 0
- Company Profile:
A device for measuring the moisture in a gaseous atmosphere, such as the air, usually as percent relative humidity. Mechanical hygrometers detect moisture by elongation and shrinkage of a fiber or sheet or by a device attached to a needle on a dial. Electrohygrometers measure changes in an electrical property of a moisture-sensitive sensing probe and are more reliable. Determination of the aqueous-phase activity of oil muds by the Chenevert Method requires an electrohygrometer and a series of salt solutions for calibration.
Industry:Oil & gas
A device for cleaning mud and mud filter cake off of the wellbore wall when cementing casing in the hole to ensure good contact and bonding between the cement and the wellbore wall. The scratcher is a simple device, consisting of a band of steel that fits around a joint of casing, and stiff wire fingers or cable loops sticking out in all directions around the band (360-degree coverage). A scratcher resembles a bottlebrush, but its diameter is greater than its height. Importantly, for scratchers to be effective, the casing must be moved. This movement may be reciprocal motion in and out of the wellbore, rotary motion, or both. In general, the more motion, the better the cement job will be.
Industry:Oil & gas
A device fitted to the top joint of a casing string to hold a cement plug before it is pumped down the casing during the cementing operation. In most operations, a bottom plug is launched before the spacer or cement slurry. The top plug is released from the cement head after the spacer fluid. Most cement heads can hold both the top and bottom plugs. A manifold incorporated into the cement head assembly allows connection of a fluid circulation line.
Industry:Oil & gas
A desilter unit in which the underflow is further processed by a fine vibrating screen, mounted directly under the cones. The liquid underflow from the screens is fed back into the mud, thus conserving weighting agent and the liquid phase but at the same time returning many fine solids to the active system. Mud cleaners are used mainly with oil- and synthetic-base muds where the liquid discharge from the cone cannot be discharged, either for environmental or economic reasons. It may also be used with weighted water-base fluids to conserve barite and the liquid phase.
Industry:Oil & gas
A descriptive term for the lack of affinity (or repulsion) that a solid material has for the liquid in which the solid is dispersed. For example clay is lyophobic to oil.
Industry:Oil & gas
A descriptive term for the strong affinity that a solid material (usually a colloid) has for the liquid in which the solid is dispersed. For example, clay is a lyophilic colloid in water.
Industry:Oil & gas
A descriptive term for a fluid with shear-thinning characteristics that does not exhibit thixotropy. Most effective drilling fluids are shear thinning, although most also exhibit some gel-building characteristics. Pseudoplastic rheology, low viscosity at high shear rates and high viscosity at low shear rates, benefits several aspects of drilling-higher drilling rate and improved cuttings lifting. Bingham plastic fluids, power-law fluids and Herschel-Bulkley fluids fall in the psuedoplastic category of rheology.
Industry:Oil & gas
A description of the internal area and surfaces of a tool or tubular assembly through which there is an unimpeded internal diameter. In some cases, fullbore is used to describe the form of a nominal internal diameter that extends over the length of the tool or interval without any variation. In other applications, the term simply implies an ability to pass a ball or similar item of a stated drift diameter through the assembly.
Industry:Oil & gas
A deposit or coating formed on the surface of metal, rock or other material. Scale is caused by a precipitation due to a chemical reaction with the surface, precipitation caused by chemical reactions, a change in pressure or temperature, or a change in the composition of a solution. The term is also applied to a corrosion product. Typical scales are calcium carbonate, calcium sulfate, barium sulfate, strontium sulfate, iron sulfide, iron oxides, iron carbonate, the various silicates and phosphates and oxides, or any of a number of compounds insoluble or slightly soluble in water.
Industry:Oil & gas
A dense mineral whose specific gravity is 4. 67 g/cm<sup>3</sup>, composed of FeO路TiO<sub>2</sub>. Ilmenite is used as a weighting agent for cement and mud.
Industry:Oil & gas
