Oil and Gas Terms Beginning with “S” — Page 6

A shear pin is a precision-machined sacrificial fastener, typically manufactured from brass, stainless steel, or aluminum alloy, that retains two sliding or moving components of a downhole tool in a fixed position until… Read more →

A shear ram is a specific type of blowout preventer (BOP) closing element fitted with hardened tool steel blades designed to physically cut through the drillpipe in the wellbore when the BOP is closed — providing the… Read more →

Shear rate is the velocity gradient of a fluid flowing between two surfaces, expressed mathematically as dv/dy (the change in velocity with respect to distance perpendicular to flow) and measured in reciprocal seconds… Read more →

Shear stock is the calibrated bar or rod material from which shear pins are cut for use in downhole slickline tools, mechanical setting tools, and intervention assemblies that depend on a deliberate, predictable… Read more →

Shear strain is the dimensionless measure of distortional deformation in a continuum body, defined as the tangent of the change in angle between two material lines that were initially perpendicular to each other; for… Read more →

Shear strength in petroleum geomechanics and drilling engineering is the maximum shear stress that a rock or soil material can sustain before failing along a shear plane, defined by the Mohr-Coulomb failure criterion as… Read more →

A shear strength measurement test in petroleum geomechanics is a laboratory or in-situ procedure that determines the resistance of a rock, soil, or sediment sample to failure along a shear plane under applied normal… Read more →

Shear stress in drilling fluid engineering is the tangential force per unit area required to cause one layer of fluid to slide past an adjacent layer at a specified shear rate — a fundamental rheological property that… Read more →

A shear-seal blowout preventer (shear-seal BOP) is a specialized pressure-control equipment item commonly fitted to wellheads during well intervention operations on live (pressurized) wells — most commonly associated… Read more →

The shear strength measurement test in petroleum geomechanics and drilling engineering encompasses the family of laboratory procedures applied to rock and soil cores to quantify resistance to shear failure — including… Read more →

A sheave is a grooved, rotating pulley wheel mounted on a fixed axle within the crown block or traveling block of a drilling rig's block-and-tackle hoisting system, designed to guide and redirect the drill line (wire… Read more →

A sheen in the oil and gas industry context is a thin film of petroleum or petroleum-derived liquid (typically crude oil, refined petroleum products, drilling fluid base oil, or produced water containing dissolved… Read more →

What Is a Sheen Test? A sheen test is a regulatory compliance procedure required by the US Environmental Protection Agency (EPA) under National Pollutant Discharge Elimination System (NPDES) permits to detect the… Read more →

The continental shelf in petroleum geology is the relatively flat, shallow submarine platform extending from the shoreline of a continent to the shelf break (the point where water depth increases more steeply, typically… Read more →

A shifted spectrum in petroleum geophysics and NMR (nuclear magnetic resonance) logging refers to a frequency or relaxation-time distribution that has been systematically displaced from its expected baseline position —… Read more →

A shifting tool is a downhole wireline or coiled tubing tool designed to mechanically shift (open or close) sliding sleeves, side pocket mandrels, flow control valves, and other mechanically actuated completion… Read more →

(noun) A guide fitting attached to the bottom of a casing string, liner, or other tubular that facilitates running the string into the wellbore by providing a rounded or tapered profile to deflect past ledges, dog legs,… Read more →

The shoe track in a casing cementing operation is the annular space inside the casing string between the guide shoe (or float shoe) at the very bottom of the casing and the float collar (a one-way check valve) installed… Read more →

To "shoot a level" is field shorthand for performing an acoustic fluid-level survey on a pumping or shut-in oil well using a wellhead-mounted acoustic gun and microphone, an instrument package commonly identified by the… Read more →

To perforate a wellbore in preparation for production. Read more →

A short trip is an abbreviated round trip of drillpipe (typically 10 to 20 stands of pipe, equivalent to roughly 300 to 600 meters of drillstring) out of and back into the wellbore, performed without removing the… Read more →

A short-path multiple is a type of seismic reflection event in which energy travels a shorter-than-expected ray path by reflecting multiple times between closely spaced reflectors (such as the seafloor and a shallow… Read more →

Shot depth in seismic exploration refers to the location of an explosive seismic source below the ground surface — applicable to onshore seismic surveys that use explosive sources (typically dynamite or specialized… Read more →

A surface detection technique to verify that perforating guns have fired. This technique typically employs sensors that detect vibration or hydraulic shock at surface, and is used with TCP operations. Read more →

One of a number of locations or stations at the surface of the Earth at which a seismicsource is activated. Read more →

A shoulder bed is the formation layer immediately above or below a target bed of interest that contaminates the logging tool's measurement in the target bed by contributing its own resistivity, gamma ray, acoustic, or… Read more →

A show, in drilling and wellsite geology, is the first surface evidence that the bit has penetrated a hydrocarbon-bearing rock. The two classical manifestations are an oil show, observed on drill cuttings as a bright… Read more →

Shut-in bottomhole pressure (SIBHP) is the static reservoir pressure measured at the depth of the producing formation in a well that has been shut in (all flow stopped at surface) for a sufficient period to allow the… Read more →

Shut-in bottomhole pressure (SIBHP) is the static reservoir pressure measured at the depth of the producing formation in a well that has been shut in (all flow stopped at surface) for a sufficient period to allow the… Read more →

Shut-in pressure (SIP) is the wellbore pressure measured after a producing or injecting well is closed at surface (shut in) and allowed to stabilize, with the well valves closed so that no fluid is flowing either into… Read more →