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Schlumberger Limited
Settore: Oil & gas
Number of terms: 8814
Number of blossaries: 0
Company Profile:
A small fish eye, typically invisible, but which can nevertheless cause formation damage by polymer plugging of pore throats. Microgels may be formed by adding polymer too quickly when viscosifying a completion brine.
Industry:Oil & gas
A small box mounted on a shaker screen that takes drilling fluid from the return flow line and distributes it across the surface of the screens via adjustable weirs.
Industry:Oil & gas
A slurry that consists of bentonite, cement or polymers mixed into an oil; bentonite in diesel oil is commonly used as a gunk plug. A small batch of the slurry is pumped down a well that has lost circulation to seal the leaky zone. The gunk plug may or may not be squeezed by pressure into the zone. Water downhole interacts with the bentonite, cement or polymers to make a sticky gunk.
Industry:Oil & gas
A short length of drill collar that has male threads on one end and female on the other. It is screwed onto the bottom of the kelly or topdrive and onto the rest of the drillstring. When the hole must be deepened, and pipe added to the drillstring, the threads are unscrewed between the saver sub and the rest of the drillstring, as opposed to between the kelly or topdrive and the saver sub. This means that the connection between the kelly or topdrive and the saver sub rarely is used, and suffers minimal wear and tear, whereas the lower connection is used in almost all cases and suffers the most wear and tear. The saver sub is expendable and does not represent a major investment. However, the kelly or topdrive component threads are spared by use of a saver sub, and those components represent a significant capital cost and considerable downtime when replaced.
Industry:Oil & gas
A simple alcohol (C<sub>3</sub>H<sub>7</sub>OH) used as a solvent in some mud analyses. A 50/50 xylene/IPA mixture was used in the past as an emulsion breaker for oil mud but has been replaced with propylene glycol normal propyl ether (PNP).
Industry:Oil & gas
A siliceous or siliceous and aluminous material that possesses little or no cementitious value. In a finely divided form and in the presence of moisture, however, pozzolan reacts chemically with calcium hydroxide to form compounds possessing cementitious properties.
Industry:Oil & gas
A set of high-pressure valves and associated piping that usually includes at least two adjustable chokes, arranged such that one adjustable choke may be isolated and taken out of service for repair and refurbishment while well flow is directed through the other one.
Industry:Oil & gas
A set of two or more BOPs used to ensure pressure control of a well. A typical stack might consist of one to six ram-type preventers and, optionally, one or two annular-type preventers. A typical stack configuration has the ram preventers on the bottom and the annular preventers at the top. The configuration of the stack preventers is optimized to provide maximum pressure integrity, safety and flexibility in the event of a well control incident. For example, in a multiple ram configuration, one set of rams might be fitted to close on 5-in. Diameter drillpipe, another set configured for 4 1/2-in. Drillpipe, a third fitted with blind rams to close on the openhole and a fourth fitted with a shear ram that can cut and hang-off the drillpipe as a last resort. It is common to have an annular preventer or two on the top of the stack since annulars can be closed over a wide range of tubular sizes and the openhole, but are typically not rated for pressures as high as ram preventers. The BOP stack also includes various spools, adapters and piping outlets to permit the circulation of wellbore fluids under pressure in the event of a well control incident.
Industry:Oil & gas
A set of pulleys used to gain mechanical advantage in lifting or dragging heavy objects. There are two large blocks on a drilling rig, the crown block and the traveling block. Each has several sheaves that are rigged with steel drilling cable or line such that the traveling block may be raised (or lowered) by reeling in (or out) a spool of drilling line on the drawworks.
Industry:Oil & gas
A series of double salts of aluminum sulfate and potassium sulfate with the formula Al<sub>2</sub>(SO<sub>4</sub>)<sub>3</sub>路K<sub>2</sub>SO<sub>4</sub>路nH<sub>2</sub>O. Alum is used as a colloidal flocculant in wastewater cleanup.
Industry:Oil & gas