Oil and Gas Terms Beginning with “S” — Page 12

To place the male threads of a piece of the drillstring, such as a joint of drillpipe, into the mating female threads, prior to making up tight. Read more →

To guide and engage components that are designed to couple, such as a seal assembly in a sealborepacker. Read more →

A stabbing valve (also called a drill pipe stabbing valve or Kelly cock lower sub) is a manually operated valve that can be quickly installed on the top of the drill string at the rig floor by stabbing it onto the open… Read more →

Stabilization in oil and gas refers to the process of removing dissolved light hydrocarbon components (primarily methane through butane, C1 to C4) from crude oil or condensate at a producing facility, reducing the… Read more →

A term describing a flowing well when its rate of production through a given choke size remains constant, or in the case of a pumping well, when the fluid column within the well remains constant in height. Read more →

A stabilized gas well is a producing gas well operating at a constant production rate where the wellhead pressure changes by no more than a small specified amount as a function of time — providing the steady-state… Read more →

A stable arch is a self-supporting granular structure that forms naturally across the face of a perforation or within pore throats in weakly consolidated formations when individual sand grains bridge together in a… Read more →

A stack in seismic data processing is the summed composite of multiple individual seismic traces that share a common midpoint (CMP) or other geometric characteristic, produced by aligning the traces to remove the… Read more →

Stacking velocity is the velocity value that, when used in the normal moveout (NMO) correction equation T(x) = sqrt(T0^2 + x^2/Vstk^2), best flattens a reflection hyperbola on a common midpoint (CMP) gather so that… Read more →

What Is Stage Separation? Stage separation is a surface oil and gas processing technique that uses two or more sequential separators operating at progressively lower pressures to separate reservoir fluid into gas, oil,… Read more →

Staged fracturing (also called multi-stage hydraulic fracturing or multi-stage fracturing) is a completion technique in which a horizontal or vertical wellbore is divided into multiple discrete intervals (stages) that… Read more →

A stand is a section of drill string consisting of two or three joints of drill pipe or drill collars screwed together and stored upright in the derrick or mast while tripping in or out of the hole, allowing the driller… Read more →

A standpipe in drilling operations is the vertical or near-vertical rigid steel pipe mounted on the side of the drilling derrick or mast that connects the high-pressure mud pumps at the drill floor level to the rotary… Read more →

A standard batch is a specific batch-treatment technique used in corrosion control of producing oil wells, where a measured quantity of corrosion inhibitor chemical is introduced into the well annulus and allowed to… Read more →

In a subsurface sucker-rod pump, a valve that permits flow up the tubing to fill the pump-barrel chamber while preventing downward flow. Read more →

A piece of material designed to hold a logging tool a certain distance away from the borehole wall. It is usually made of hard rubber and consists of four to six fins of the desired length. Read more →

A standpipe in drilling operations is the vertical or near-vertical rigid steel pipe mounted on the side of the drilling derrick or mast that connects the high-pressure mud pumps at the drill floor level to the rotary… Read more →

What Is Starch in Drilling Fluids? Starch is a polysaccharide drilling-mud additive derived from corn, wheat, potatoes, and similar plants that controls fluid loss in water-based muds ranging from freshwater to… Read more →

A static aging test is a laboratory procedure for evaluating the thermal stability of a drilling fluid by placing a sample in a sealed pressurized cell and exposing it to a specified elevated temperature for a defined… Read more →

Static correction (or statics) in seismic data processing refers to the time shifts applied to individual seismic traces to compensate for the effect of near-surface velocity and topography variations on the recorded… Read more →

Static filtration is a filtration process in which the drilling fluid or cement slurry being tested remains stationary against a filter medium, allowing the filter cake to grow continuously thicker as filtration… Read more →

The level to which fluid rises in a well when the well is shut in. The hydrostatic head of this fluid is equal to the well bottomhole pressure. Read more →

Static pressure in petroleum engineering is the pressure measured in a well or reservoir after the well has been shut in for a sufficient period of time to allow the pressure transient caused by production (or… Read more →

What Is the Static Spontaneous Potential? The static spontaneous potential (SSP) is the theoretical maximum spontaneous potential deflection that would be measured in a permeable, shale-free formation if there were no… Read more →

Static-aging test (hyphenated) is an alternate written form of static aging test, referring to the same laboratory procedure in which a drilling fluid sample is sealed in a container and heated to a specified… Read more →

A form of homogeneity in a single characteristic. Local stationarity occurs when two or more adjacent, locally homogeneous samples yield similar values of the property of interest. Read more →

The slip set on a snubbing unit located at the base of the jack. Two sets of stationary slips are available, one set for pipe-heavy conditions and another for pipe-light conditions. Read more →

Stationary snubbers in oil and gas drilling and well control operations are fixed pipe-holding devices installed on the snubbing unit or wellhead assembly that grip and support the drillpipe or tubing string during… Read more →

Statistics in petroleum engineering and geoscience is the branch of mathematics concerned with collecting, analyzing, interpreting, and presenting quantitative data — applied across the full spectrum of oil and gas… Read more →

Steady state in physical and engineering systems is the operational condition where a system has reached equilibrium for the specific measurement or phenomenon being analyzed — providing the operational reference state… Read more →