- Branche: Oil & gas
- Number of terms: 8814
- Number of blossaries: 0
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Gas that rises to the surface, usually detected because it reduces the density of the drilling mud. Gas detectors, which the mud logger monitors, measure combustible gases (methane, ethane, butane and others). The mud logger reports total gas, individual gas components, or both, on the mud log. In extreme cases, gas visibly bubbles out of the mud as it returns to the surface. Because the mud does not circulate to the surface for a considerable time, sometimes lagging several hours after a formation is drilled, a gas show may be representative of what happened in the wellbore hours (or many feet) prior to the current total depth of the well.
Industry:Oil & gas
Gas that is introduced into the drilling mud from a source other than the formation. Contamination gas normally evolves as a by-product of oil-base mud systems and those using volatile additives such as diesel fuel or other lubricants.
Industry:Oil & gas
Gas entrained in the drilling fluid during a pipe trip, which typically results in a significant increase in gas that is circulated to surface. This increase arises from a combination of two factors: lack of circulation when the mud pumps are turned off, and swabbing effects caused by pulling the drillstring to surface. These effects may be seen following a short trip into casing or a full trip to surface.
Industry:Oil & gas
Formation solids contained in a mud system, generally considered to be detrimental to the drilling operation because they produce high plastic viscosity, yield point and gel strengths and build poor-quality filter cakes. They also occupy space that is needed for barite in high-density muds. Drill solids cause excessive wear in the mud pumps and other rig equipment. Solids control is aimed at economically and efficiently removing drill solids. This implies removal as soon as possible after they enter the mud system, while the particles are at their largest size.
Industry:Oil & gas
Ethylenediamine tetraacetic acid, the reagent used to titrate for calcium and magnesium ions (hardness ions) in water samples. It is also known as versenate or titraver.
Industry:Oil & gas
Equipment used to measure filtration under dynamic conditions. Two commercial dynamic-filtration testers are available, one of which uses a thick-walled cylinder with rock-like characteristics as the filter medium to simulate radial flow into a wellbore. The other tester uses flat porous disks, such as paper or fused ceramic plates, as filter media. In a dynamic test, filter cake is continually eroded and deposited. Data from this test include a steady-state filtration rate measured during the test, and cake thickness, cake quality and return permeability of the filter medium measured at the conclusion of a test. There is no API standardized test equipment or procedure.
Industry:Oil & gas
During a titration procedure in analytical chemistry, the point at which reagent addition should be immediately stopped and the volume of reagent recorded. The endpoint represents the end of a specific chemical reaction, such as precipitation, and may be indicated by a color change, a voltage or pH reading or an inflection point on an graphical plot of the data.
Industry:Oil & gas
Drilling operations using a water-base drilling fluid that contains few solids. Clear-water drilling is done in "hard rocks" in which density and fluid loss are not critical. Rapid drilling rate is the incentive for using a solids-free mud. Fluid returned to the surface must be screened and processed by hydrocyclones and centrifuges to remove larger solids. Colloidal solids can be agglomerated by adding polymers and removing the aggregates. Polymers such as acrylates, acrylamides and partially-hydrolyzed polyacrylamides are used. They are added at the flowline as mud exits the well or added in pits downstream from the flowline.
Industry:Oil & gas
Drilling fluid whose bulk, unpressurized density is reduced as a small volume of gas displaces an equivalent volume of liquid. The derrickman periodically measures mud density and communicates the results to the rig team via an intercom. He usually reports something like "9. 6 heavy," "10. 4," or "13. 2 light," indicating more than 9. 6 pounds per gallon, 10. 4 pounds per gallon, or less than 13. 2 pounds per gallon, respectively. Each tenth of a pound per gallon is referred to as a "point" of mud weight. Note that for this low-accuracy measurement, no direct mention of gas cut is made. A gas cut is inferred only if the mud returning to the surface is significantly less dense than it should be. In the case of the mud logger's measurement, "units" of gas (having virtually no absolute meaning) are reported. For the mud logger's measurement, a direct indication of combustible gases is made, with no direct correlation to mud weight.
Industry:Oil & gas
Drill collars (usually straight drill collars) that have been machined with a reduced diameter at the box (up) end so that they may be more easily handled with open-and-close elevators. The elevators close around the reduced-diameter section, latch securely, and a shoulder on the elevators prevents the larger diameter end of the collar from passing through the elevators, so the collars can be lifted. If zip grooves are not used on the collars, special lifting subs must be threaded into each stand of collars for lifting, which is time-consuming and less efficient than zip grooves. The primary drawback to zip grooves is that they may reduce the life of the collar by putting an effective limit on how many times the collar threads may be recut.
Industry:Oil & gas
