Oil and Gas Terms Beginning with “S” — Page 8

A technique for acquiring deviation information from a borehole on a slickline. In high-angle wells, a multishot technique is usually used instead. Read more →

A single-tank composite sample is a representative liquid mixture created by combining individual samples drawn from the upper, middle, and lower sections of a single oilfield storage tank, blended in proportion to the… Read more →

Sinistral (from the Latin sinistra, meaning left) describes a strike-slip or left-lateral fault in which an observer standing on either side of the fault and looking across it sees the opposite block moving to the left;… Read more →

Sintered, in the context of petroleum engineering and downhole equipment, refers to a material or component produced by sintering — the process of compacting and bonding a powdered solid material (metal, ceramic, or… Read more →

A property or characteristic that has the form of a sine wave. Read more →

Sized calcium carbonate (also called calcium carbonate bridging agent or CaCO3 bridging material) is a chemically soluble, acid-dissolvable mineral additive incorporated into completion fluids, drill-in fluids, and… Read more →

Sized salt is sodium chloride (NaCl) solid particles that have been processed to provide a specified minimum and maximum range of particle sizes and that may also have a specified distribution of sizes within that range… Read more →

The degree to which a distribution has lost the bilateral symmetry of a normal distribution. Skewness is usually expressed qualitatively rather than quantitatively. Read more →

To skid in offshore drilling operations is to slide a drilling rig laterally across the deck of a fixed platform or jack-up rig from one well slot position to another, using hydraulic cylinders pushing against… Read more →

What Is Skin Factor in Oil and Gas? The skin factor (or simply skin , symbol S) is a dimensionless number that quantifies the deviation of a well's actual productivity from its theoretical productivity in an undamaged… Read more →

The effective depth of penetration of an electromagnetic wave in a conductive medium. The skin depth is the distance in which the wave decays to 1/e (about 37%) of its value; it can be expressed as: Read more →

Skin effect is a dimensionless parameter (S) in well test analysis that quantifies the additional pressure drop near the wellbore relative to what would be expected for an ideal undamaged well: a positive skin indicates… Read more →

What Is Skin Factor? The skin factor (S or S_skin) is a dimensionless number that quantifies the additional pressure drop in the near-wellbore region compared to ideal, undamaged radial flow through an infinite… Read more →

A specially designed drilling rig capable of drilling directional wells. Read more →

A process used in seismic processing to stack, or sum, traces by shifting traces in time in proportion to their offset. This technique is useful in areas of dipping reflectors. Read more →

Slickline is a single-strand, solid wire used to run and retrieve tools and flow-control equipment in producing oil and gas wells without killing the well or removing the production tubing, distinguishing it from… Read more →

In directional drilling, a slide is a drilling mode in which the drill string is held stationary and not rotated from surface while the downhole motor (mud motor or positive-displacement motor) turns the bit using the… Read more →

A sliding sleeve (also called a sliding sleeve valve, production sleeve, or ported sleeve) is a completion device installed in the production tubing string that provides a controllable flow path between the inside of… Read more →

What Is a Slim Hole Well? A slim hole well is a borehole drilled with a reduced diameter profile throughout some or all of its depth, typically using bit sizes of 6 inches or smaller compared to the 8.5-12.25 inch bits… Read more →

What Is a Slim Tube Test? A slim tube test is a laboratory procedure used to determine the minimum miscibility pressure (MMP) of a gas injection enhanced oil recovery scheme by displacing reservoir crude oil through a… Read more →

Bacteria that can live with or without oxygen and produce mats of high-density slime that cover surfaces. Their primary detrimental effects are the protection of sulfate-reducing bacteria and pore plugging. Read more →

Bacteria that can live with or without oxygen and produce mats of high-density slime that cover surfaces. Their primary detrimental effects are the protection of sulfate-reducing bacteria and pore plugging. Read more →

What Is a Slimhole Well? A slimhole well is a wellbore drilled with a reduced-diameter borehole profile, characteristically using bit sizes below 6 inches in the producing section, enabling significant reductions in rig… Read more →

The phenomenon in multiphase flow when one phase flows faster than another phase, in other words slips past it. Because of this phenomenon, there is a difference between the holdups and cuts of the phases. Read more →

Slip and cut in drilling engineering is the maintenance procedure for the drilling line (wire rope that connects the traveling block, hook, and swivel assembly to the draw-works drum) in which a predetermined length of… Read more →

A slip joint is a completion component designed to accommodate axial movement of the production tubing string while maintaining a continuous hydraulic seal between a sliding inner mandrel and an outer housing, allowing… Read more →

A slip lock is a mechanical locking device used in wellbore completion and well control equipment to prevent the unintentional movement or withdrawal of slips (the wedge-shaped gripping elements that grip casing or pipe… Read more →

Slip velocity in multiphase flow through pipes and wellbores is the difference between the average in-situ velocities of two or more fluid phases flowing simultaneously through the same conduit, arising because the… Read more →

Slip and cut is the drilling rig maintenance procedure in which a measured length of drilling line (the wire rope connecting the draw-works drum to the traveling block assembly through the crown block sheaves) is… Read more →

Any self-gripping toothed device functioning substantially as above, but gripping components other than drillstring, such as wireline, metal sinker bars, or drill collars. Read more →