Oil and Gas Terms Beginning with “S” — Page 11

The distribution of gamma ray energies, or the number of gamma rays as a function of gamma ray energy. Read more →

The apparent loss of intensity of a gravitational or magnetic field with distance. Spherical divergence decreases energy with the square of the distance. Read more →

A flow regime that occurs when the predominant flow pattern in the reservoir is toward a point. Spherical flow occurs for partial penetration and limited-entry completions. This flow regime is recognized as a -1/2 slope… Read more →

A technique for focusing an electrode device based on maintaining a spherical equipotential surface centered at the main current electrode. Unlike the laterolog, which tries to maintain equipotential lines parallel to… Read more →

The solution to the Laplace equation expressed as spherical coordinates. The normal modes of the Earth, or the reverberations that follow earthquakes, have the form of spherical harmonics. Love waves and Rayleigh waves… Read more →

A ball-shaped vessel used for fluid separation. A spherical separator can be used for two-phase or three-phase separation purposes.Spherical separators are less efficient than either horizontal or vertical cylindrical… Read more →

A wave generated from a point source, such as that generated by an underground explosion. Typical seismic sources such as vibrators and air-gun arrays emit elastic waves that are assumed to be spherical waves. Read more →

The structurally lowest point in a hydrocarbon trap that can retain hydrocarbons. Once a trap has been filled to its spill point, further storage or retention of hydrocarbons will not occur for lack of reservoir space… Read more →

A productionlogging method that uses a small propeller turned by fluid movement. The number of turns of the propeller can be related to the amount of fluid passing through the instrument.These devices are used to… Read more →

For a two-detector density tool, the plot of long-spacing versus short-spacing count rates for different formation densities, mudcake densities and mudcake thicknesses. The plot takes its name from the spine, which is… Read more →

What Is a Spinner Flowmeter? A spinner flowmeter is a downhole production logging tool that measures in-situ fluid velocity inside a wellbore by counting the rotational speed of an impeller or vane assembly. As wellbore… Read more →

The change in direction of rotation that occurs when a spinner flowmeter tool is moving in the same direction, but faster, than the fluid. When the tool is stationary, moving against the fluid flow, or moving in the… Read more →

A length of ordinary steel link chain used by the drilling crew to cause pipe being screwed together to turn rapidly. This is accomplished by first carefully wrapping the chain around the lower half of the tool joint… Read more →

A standard laboratory instrument to measure interfacial tension. The method is particularly applicable to values of interfacial tension below 1 mN/m and especially below 10-2 mN/m, as may occur when employing… Read more →

A mathematical procedure for connecting data points with a smooth line. The line does not necessarily go through the data points, but its direction and curvature are affected by all the data points. The "stiffness" of… Read more →

What Is Spontaneous Potential? The spontaneous potential (SP) log measures the natural electrochemical voltage, in millivolts, generated between a moving borehole electrode and a fixed surface reference electrode as the… Read more →

A device used to handle and temporarily store a coiled tubing string. Spoolers generally are configured with a removable drum that allows transport spools to be inserted, allowing a new string to be spooled onto a reel.… Read more →

To accurately place a fluid, or fluid interface, at a given position within the wellbore. Treatment fluids such as cementslurries and stimulation fluids for localized treatment often require accurate placement.… Read more →

A sample of liquid or sediments obtained at a specific depth inside a tank using a thief or a bottle. Spot samples are analyzed to determine the gravity of the oil and BS&W content of the fluid in the tank. Read more →

A small volume or pill of fluid placed in a wellbore annulus to free differentially stuck pipe. Oil-base mud is the traditional stuck-pipe spotting fluid. Speed in mixing and placing the spot is of primary importance to… Read more →

The geometrical pattern of groups of geophones relative to the seismicsource. The output from a single shot is recorded simultaneously by the spread during seismic acquisition. Common spread geometries include in-line… Read more →

The additional loss in amplitude of an electromagnetic wave emitted by an electromagnetic propagation or dielectric propagation measurement compared to that of a plane wave. The spreading loss depends on the geometry of… Read more →

What Is a Spud? A spud marks the moment drilling begins on a new well, the first rotation of the drill bit breaking ground at the surface or seafloor. Operators report the spud date to regulators including the AER in… Read more →

Mud used to drill a well from surface to a shallow depth. Guar gum or saltgel are commonly used offshore as spud mud. Onshore spud mud is usually a water-base mud containing bentoniteclay that is flocculated with lime.… Read more →

The instantaneous volume (spurt) of liquid that passes through a filter medium prior to deposition of a competent and controlling filter cake. In static filtration, the spurt volume can be a disproportionately large… Read more →

A log in which the changes in reading with depth only occur abruptly, with no transition. A square log is often an approximation of a real log, in which the continuously varying input log has been approximated by… Read more →

What Is Squeeze Cementing? Squeeze cementing forces cement slurry under pressure through perforations, channels, or voids in an existing wellbore to restore or establish zonal isolation between formations. Operators… Read more →

A manifold connected within the surface treating lines that is configured to enable control and routing of fluids during a squeeze operation. Most squeeze manifolds have treating line connections with the tubing string,… Read more →

A type of retrievable packer used in squeeze-cementing operations. Key features include a bypass system and hold-down slips. The bypass system prevents surge and swab effects when running and retrieving the packer and… Read more →

The final or maximum pressure that can be applied during a squeeze operation. When conducting a squeeze-cement job, it is generally desirable to achieve a high final squeeze pressure that indicates the target holes and… Read more →