- Branża: Oil & gas
- Number of terms: 8814
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The adapter between the first casing string and either the BOP stack (during drilling) or the wellhead (after completion). This adapter may be threaded or welded onto the casing, and may have a flanged or clamped connection to match the BOP stack or wellhead.
Industry:Oil & gas
The action of forcing a pipe or tubular into a well against wellbore pressure. Well-intervention techniques in live wells, such as coiled tubing and snubbing, use equipment designed to apply the necessary forces while supporting the tubing and safely containing wellbore pressure and fluids.
Industry:Oil & gas
The action of coating rock grains and plugging off the permeability of a productive reservoir during drilling. The term is seldom used today, but refers to formation damage by mud solids. By proper selection of solids, such as bridging materials and drill-in fluids, mudding off can be minimized.
Industry:Oil & gas
The action in which mud particles (barite) become coated with an oily substance that causes the particles to agglomerate. This can cause barite settlement or removal by shaker screens. The problem can occur when mud additives, such as fatty-acid soaps or mud lubricants, are incompatible with the mud system or react adversely to contaminating ions.
Industry:Oil & gas
The act or means of controlling (usually lowering) the volume of filtrate that passes through a filter medium. Control of fluid loss for a mud is achieved by several means, one of which is by addition of fluid-loss-control materials to the mud system. Another is to change the mud chemistry to make the materials already present work better. Adding a clay deflocculant to freshwater mud typically improves fluid-loss control.
Industry:Oil & gas
The act of strongly agitating the mud pits, particularly on bottom and in corners, with the mud guns. Gunning the pits lifts settled barite, which can result in sudden, perhaps undesirable, increase in mud density in the pits.
Industry:Oil & gas
The act of reducing the viscosity of a suspension by adding a thinning agent, also known as a deflocculant.
Industry:Oil & gas
The act of putting drillpipe into the wellbore when the blowout preventers (BOPs) are closed and pressure is contained in the well. This is necessary when a kick is taken, since well kill operations should always be conducted with the drillstring on bottom, and not somewhere up the wellbore. If only the annular BOP has been closed, the drillpipe may be slowly and carefully lowered into the wellbore, and the BOP itself will open slightly to permit the larger diameter tool joints to pass through. If the well has been closed with the use of ram BOPs, the tool joints will not pass by the closed ram element. Hence, while keeping the well closed with either another ram or the annular BOP, the ram must be opened manually, then the pipe lowered until the tool joint is just below the ram, and then the ram closed again. This procedure is repeated whenever a tool joint must pass by a ram BOP. Rig crews are usually required to practice ram-to-ram and ram-to-annular stripping operations as part of their well control certifications. In stripping operations, the combination of the pressure in the well and the weight of the drillstring is such that the pipe falls in the hole under its own weight, whereas in snubbing operations the pipe must be pushed into the hole.
Industry:Oil & gas
The act of putting drillpipe into the wellbore when the blowout preventers (BOPs) are closed and pressure is contained in the well. Snubbing is necessary when a kick is taken, since well kill operations should always be conducted with the drillstring on bottom, and not somewhere up the wellbore. If only the annular BOP has been closed, the drillpipe may be slowly and carefully lowered into the wellbore, and the BOP itself will open slightly to permit the larger diameter tool joints to pass through. If the well has been closed with the use of ram BOPs, the tool joints will not pass by the closed ram element. Hence, while keeping the well closed with either another ram BOP or the annular BOP, the ram must be opened manually, then the pipe lowered until the tool joint is just below the ram, and then closing the ram again. This procedure is repeated whenever a tool joint must pass by a ram BOP. In snubbing operations, the pressure in the wellbore acting on the cross-sectional area of the tubular can exert sufficient force to overcome the weight of the drillstring, so the string must be pushed (or "snubbed") back into the wellbore. In ordinary stripping operations, the pipe falls into the wellbore under its own weight, and no additional downward force or pushing is required.
Industry:Oil & gas
The act of pulling the drillstring out of the hole or replacing it in the hole. A pipe trip is usually done because the bit has dulled or has otherwise ceased to drill efficiently and must be replaced.
Industry:Oil & gas
