S
safety clamp n: a clamp placed tightly around a drill collar that is
suspended in the rotary table by drill collar slips.
safety joint n: an accessory to a fishing tool,
placed above it. If the tool cannot be disengaged from the fish, the safety
joint permits easy disengagement of the string of pipe above the safety joint.
Thus, part of the safety joint and the tool attached to the fish remain in the
hole and become part of the fish.
safety slide n: a device normally mounted near the
monkey board to afford the derrickhand a means of quick exit to the surface in
case of emergency. It is usually affixed to a wireline, one end of which is
attached to the derrick or mast and the other end to the surface. To exit by
the safety slide, the derrickhand grasps a handle on it and rides it down to
the ground. Also called a Geronimo.
salinity log n: a special nuclear well log that
produces an estimate of the relative amounts of oil, gas, or salt water in a
formation. This log is electronically adjusted to reflect gamma ray emissions
resulting from the collision of neutrons with chlorine atoms in the
formations.
samples n pl: 1. the well cuttings obtained at
designated footage intervals during drilling. From an examination of these
cuttings, the geologist determines the type of rock and formations being
drilled and estimates oil and gas content. 2. small quantities of well fluids
obtained for analysis.
sand n: 1. an abrasive material composed of small quartz grains formed
from the disintegration of pre-existing rocks.
sand consolidation n: any one of several methods by
which the loose, unconsolidated grains of a producing formation are made to
adhere to prevent a well from producing sand but permit it to produce oil and
gas.
sand control n: any method by which large amounts of
sand in a sandy formation are prevented from entering the wellbore. Sand in
the wellbore can cause plugging and premature wear of well equipment.
sandfrac n: method of fracturing subsurface rock
formations by injecting fluid and sand under high pressure to increase
permeability. Fractures are kept open by the grains of sand.
sandline n: a wireline used on drilling rigs and
well-servicing rigs to operate a swab or bailer, to retrieve cores or to run
logging devices. It is usually 9/16 of an inch (14 millimeters) in diameter
and several thousand feet or meters long.
sandstone n: a sedimentary rock composed of
individual mineral grains of rock fragments between 0.06 and 2 millimeters
(0.002 and 0.079 inches) in diameter and cemented together by silica, calcite,
iron oxide, and so forth.
saver sub n: an expendable substitute device made up in the drill stem
to absorb much of the wear between the frequently broken joints (such as
between the kelly or top drive and the drill pipe).
scale n: 1. a mineral deposit (for example, calcium
carbonate) that precipitates out of water and adheres to the inside of pipes,
heaters, and other equipment. 2. an ordered set of gauge marks together with
their defining figures, words, or symbols with relation to which position of
the index is observed when reading an instrument.
scraper n: any device that is used to remove
deposits (such as scale or paraffin) from tubing, casing, rods, flow lines, or
pipelines.
scratcher n: a device that is fastened to the
outside of casing to remove mud cake from the wall of a hole to condition the
hole for cementing.
screening effect n: the tendency of proppants to
separate from fracture fluid when the speed, or velocity, of the fluid is low.
secondary recovery n: 1. the use of water-flooding
or gas injection to maintain formation pressure during primary production and
to reduce the rate of decline of the original reservoir drive. 2.
water-flooding of a depleted reservoir. 3. the first improved recovery method
of any type applied to a reservoir to produce oil not recoverable by primary
recovery methods. See primary recovery.
self-potential (SP) n: see spontaneous potential.
self-propelled unit n: see carrier rig.
service company n: a company that provides a
specialized service, such as a well-logging service or a directional drilling
service.
service rig n: see production rig.
service well n: 1. a nonproducing well used for
injecting liquid or gas into the reservoir for enhanced recovery. 2. a
saltwater disposal well or a water supply well.
set back v: to place stands of drill pipe and drill
collars in a vertical position to one side of the rotary table in the derrick
or mast of a drilling or workover rig. Compare lay down pipe.
set casing v: to run and cement casing at a certain
depth in the wellbore. Sometimes called set pipe.
set pipe v: see set casing.
set up v: to harden (as cement).
shaker n: shortened form of shale shaker. See shale
shaker.
shale n: a fine-grained sedimentary rock composed mostly of
consolidated clay or mud. Shale is the most frequently occurring sedimentary
rock.
 shale
shaker n: a vibrating screen used to remove cuttings from the
circulating fluid in rotary drilling operations. Also called a shaker.
shear ram n: the component in a blowout preventer
that cuts, or shears, through drill pipe and forms a seal against well
pressure.
shear ram preventer n: a blowout preventer that uses shear rams as
closing elements.
sheave (pronounced "shiv") n: 1. a grooved pulley. 2. support
wheel over which tape, wire, or cable rides.
shoulder n: 1. the flat portion machined on the base of the bit shank
that meets the shoulder of the drill collar and serves to form a
pressure-tight seal between the bit and the drill collar. 2. the portion of
the box end or the pin end of a tool joint; the two shoulders meet when the
tool joint is connected and form a pressure-tight seal.
shut in v: 1. to close the valves on a well so that it stops producing.
2. to close in a well in which a kick has occurred.
shut-in bottomhole pressure (SIBHP) n: the pressure
at the bottom of a well when the surface valves on the well are completely
closed. It is caused by formation fluids at the bottom of the well.
sidetrack v: to use a whipstock, turbodrill, or
other mud motor to drill around the original planned path of the well.
single n: a joint of drill pipe. Compare double.
single-pole rig n: a well-servicing unit whose mast
consists of but one steel tube, usually about 65 feet (19.8 meters) long.
TOP |
Back to Top
