- Industry: Oil & gas
- Number of terms: 8814
- Number of blossaries: 0
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Onshore, two elevated truss-like structures having triangular cross sections. The pipe rack supports drillpipe, drill collars or casing above the ground. These structures are used in pairs located about 20 ft (6 m) apart and keep the pipe above ground level and closer to the level of the catwalk. Pipe stored horizontally on the pipe racks can have its threads cleaned and inspected and the rig crew may roll the pipe from one end of the pipe racks to the other with relative ease. The pipe racks are usually topped with a wooden board so as to not damage pipe, especially casing, as it is rolled back and forth along the racks. When large amounts of pipe are stored, wooden sills are placed between the layers of pipe to prevent damage.
Industry:Oil & gas
One of two quantitative analysis procedures for measuring aromatic content of base oils for use in oil mud as proscribed by the API. Results of the two aromatic content tests may differ because of the way the two gas-chromatography techniques separate and identify aromatics. The Institute of Petroleum (IP) instruments are more widely available than the American Society for Testing and Materials (ASTM) instruments, and the Institute of Petroleum method measures trace levels better than the more complex ASTM method.
Industry:Oil & gas
One of three main classes of rock (igneous, metamorphic and sedimentary). Metamorphic rocks form from the alteration of preexisting rocks by changes in ambient temperature, pressure, volatile content, or all of these. Such changes can occur through the activity of fluids in the Earth and movement of igneous bodies or regional tectonic activity. The texture of metamorphic rocks can vary from almost homogeneous, or nonfoliated, to foliated rocks with a strong planar fabric or foliation produced by alignment of minerals during recrystallization or by reorientation. Common foliated metamorphic rocks include gneiss, schist and slate. Marble, or metamorphosed limestone, can be foliated or non-foliated. Hornfels is a nonfoliated metamorphic rock. Graphite, chlorite, talc, mica, garnet and staurolite are distinctive metamorphic minerals.
Industry:Oil & gas
One of three divalent cations that can be present in water, including calcium (Ca<sup>+2</sup>), magnesium (Mg<sup>+2</sup>) and ferrous (Fe<sup>+2</sup>, a form of iron). Hardness ions develop from dissolved minerals, bicarbonate, carbonate, sulfate and chloride. Bicarbonate salts cause temporary hardness, which can be removed by boiling the water and leaving behind a calcium carbonate solid. Mg<sup>+2</sup> and Fe<sup>+2</sup> ions can be removed by raising the pH (with NaOH or KOH) and then allowing the precipitated Fe(OH)<sub>2</sub> and Mg(OH)<sub>2</sub> to settle out. Calcium hardness can be removed by adding excess sodium carbonate to precipitate Ca<sup>+2</sup> as CaCO<sub>3</sub>. Hard water can be passed through an ion exchange column where hardness ions are captured on the resin. Removal of hardness is the process called water softening.
Industry:Oil & gas
One of the three main classes of rock (igneous, metamorphic and sedimentary). Sedimentary rocks are formed at the Earth's surface through deposition of sediments derived from weathered rocks, biogenic activity or precipitation from solution. Clastic sedimentary rocks such as conglomerates, sandstones, siltstones and shales form as older rocks weather and erode, and their particles accumulate and lithify, or harden, as they are compacted and cemented. Biogenic sedimentary rocks form as a result of activity by organisms, including coral reefs that become limestone. Precipitates, such as the evaporite minerals halite (salt) and gypsum can form vast thicknesses of rock as seawater evaporates. Sedimentary rocks can include a wide variety of minerals, but quartz, feldspar, calcite, dolomite and evaporite group and clay group minerals are most common because of their greater stability at the Earth's surface than many minerals that comprise igneous and metamorphic rocks. Sedimentary rocks, unlike most igneous and metamorphic rocks, can contain fossils because they form at temperatures and pressures that do not obliterate fossil remnants.
Industry:Oil & gas
One of the synthetic hydrocarbon liquids manufactured from the monomer ethylene, H<sub>2</sub>C=CH<sub>2</sub>. Polyalphaolefins have a complex branched structure with an olefin bond in the alpha position of one of the branches. Hydrogenated polyalphaolefins have olefin-carbons saturated with hydrogen, which lends excellent thermal stability to the molecule. Synthetic-base fluids (similar to oil muds) are made with the various types of synthetic liquids because the cuttings can be discharged in offshore waters, whereas discharge of cuttings coated with refined oils would be disallowed.
Industry:Oil & gas
One of the rig crew members who gets his name from the fact that he works on a platform attached to the derrick or mast, typically 85 ft (26 m) above the rig floor, during trips. On small land drilling crews, the derrickman is second in rank to the driller. Larger offshore crews may have an assistant driller between the derrickman and the driller. In a typical trip out of the hole (TOH), the derrickman wears a special safety harness that enables him to lean out from the work platform (called the monkeyboard) to reach the drillpipe in the center of the derrick or mast, throw a line around the pipe and pull it back into its storage location (the fingerboards) until it is time to run the pipe back into the well. In terms of skill, physical exertion and perceived danger, a derrickman has one of the most demanding jobs on the rig crew. Some modern drilling rigs have automated pipe-handling equipment such that the derrickman controls the machinery rather than physically handling the pipe. In an emergency, the derrickman can quickly reach the ground by an escape line often called the Geronimo line.
Industry:Oil & gas
One of the instruments that the driller uses to monitor and improve the operating efficiencies of the drilling operation. The actual measurement of weight is made with a hydraulic gauge attached to the dead line of the drilling line. As tension increases in the drilling line, more hydraulic fluid is forced through the instrument, turning the hands of the indicator. The weight that is measured includes everything exerting tension on the wire rope, including the traveling blocks and cable itself. Hence, to have an accurate weight measurement of the drillstring, the driller must first make a zero offset adjustment to account for the traveling blocks and items other than the drillstring. Then the indicated weight will represent the drillstring (drillpipe and bottomhole assembly). However, the driller is only nominally interested in this weight for most operations. The weight of interest is the weight applied to the bit on the bottom of the hole. The driller could simply take the rotating and hanging off bottom weight, say 300,000 pounds (136,200 kg), and subtract from that the amount of rotating on bottom weight, say 250,000 pounds (113,500 kg), to get a bit weight of 50,000 pounds (22,700 kg). However, most rigs are equipped with a weight indicator that has a second indicator dial that can be set to read zero ("zeroed") with the drillstring hanging free, and works backwards from the main indicator dial. After proper zeroing, any weight set on bottom (that takes weight away from the main dial), has the effect of adding weight to this secondary dial, so that the driller can read weight on bit directly from the dial.
Industry:Oil & gas
One of several flow characteristics of a material, such as a drilling fluid, completion fluid, workover fluid or cement. Shear-stress measurements made at a minimum of two shear rates are needed to define the properties of these oilfield fluids. Three parameters are sometimes used to better define fluid behavior. "Rheological properties" most often refers to the Bingham plastic fluid parameters, PV (plastic viscosity) and YP (yield point), as measured by the direct-indicating rheometer. The power-law fluid model parameters, exponent (n) and consistency (k), apply to polymer muds, although the three-parameter Herschel-Bulkley model is a better fit to polymer muds. Brookfield viscometers measure flow properties at low shear rates to determine suspension and transport of cuttings in high-angle holes.
Industry:Oil & gas
One of several classes of cement manufactured to the specifications of the American Petroleum Institute (API) Specification 10A. Classes of API cement are A, B, C, D, E, F, G and H.
Industry:Oil & gas
