دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

a technique for isolating multiple fracs using a short downhole settable ring or restriction and dropping a hard rubber ball between frac jobs. Two or more ring/ball sets can be used to stage frac a long zone.

a flow-through plug set after pumping a frac (between stages) in a multi-fraced well and sealed with a ball dropped from surface as the next frac stage is started.

n: when mud fluid pressure exceed one weak formation blast pressure results in formation being fractured and mud fluid leak to ground in drilling.

dense layer of soil containing silt and sand, but no organic matter and little clay. May have extreme hardness due to compaction.

n: a opening plug which is appllied in multi-stage cementation.

n: a set of plug which is appllied in free falling multi-stage cementation.

n: 1. water that has little or no salt dissolved in it.2. underground water, generally located near the surface, that does not contain a large amount of salt and from which most underground drinking water supplies are drawn.3. inland surface water, such as lakes, streams, and ponds, that is not salty.

n: Formation water with low salinity. Water is considered fresh when its low conductivity makes the interpretation of resistivity logs difficult. The salinity at which this becomes important depends on temperature and clay content, among other factors, but i

water with less than about 600 ppm total dissolved solids. Suitable for drinking.

n: movement of the soil resulting from alternate thawing and freezing. Frost heaving generates stress on vertical support members of pipelines in the Arctic and, by extension, on the pipe itself.

n: the phenomenon resulting when water invades rock, freezes, and, by its expansion, wedges apart the rock. Repeated freeze-thaw cycles can quickly break up any rock that has even the tiniest cracks.

n: the pump that pressurises fuel to the pressure used for injection. In a diesel engine the term is used to identify several different pumps: it is loosely used to describe the pump that transfers fuel from the main storage tank to the day tank;it is also used to describe the pump that supplies pressure to the fuel-injection pumps, although this is actually a booster-type pump. fulcrum n: the support about which a lever turns.