Annulus (oil well)

The annulus of an oil well is any void between any piping, tubing or casing and the piping, tubing, or casing immediately surrounding it. It is named after the corresponding geometric concept. The presence of an annulus gives the ability to circulate fluid in the well, provided that excess drill cuttings have not accumulated in the annulus, preventing fluid movement and possibly sticking the pipe in the borehole.

For a new well in the process of being drilled, this would be the void between the drill string and the formation being drilled. An easy way to visualise this would be to stand a straw (purple in diagram) straight up in the center of a glass of water. All of the water in between the straw and the sides of the glass would be the annulus (yellow area in diagram), with the straw itself representing the drill string and the sides of the glass representing the formation. While drilling, drilling fluid is pumped down the inside of the drill string and pushes the drill cuttings up the annulus to the surface, where the cuttings are removed from the drilling fluid (drilling mud) by the shale shakers.

Oil!

Oil! is a novel by Upton Sinclair published in 1927 told as a third person narrative, with only the opening pages written in the second person. The book was written in the context of the Harding administration's Teapot Dome Scandal and takes place in Southern California. It is a social and political satire skewering the human foibles of all its characters.

The main character is James Arnold Ross Jr., nicknamed Bunny, son of an oil tycoon. Bunny's sympathetic feelings toward oilfield workers and socialists provoke arguments with his father throughout the story.

The novel served as a loose inspiration for the 2007 film There Will Be Blood.

Characters

Oil

An oil is any neutral, nonpolar chemical substance that is a viscous liquid at ambient temperatures and is both hydrophobic (immiscible with water, literally "water fearing") and lipophilic (miscible with other oils, literally "fat loving"). Oils have a high carbon and hydrogen content and are usually flammable and slippery.

The general definition of oil includes classes of chemical compounds that may be otherwise unrelated in structure, properties, and uses. Oils may be animal, vegetable, or petrochemical in origin, and may be volatile or non-volatile. They are used for food, fuel, lubrication, and the manufacture of paints, plastics, and other materials. Specially prepared oils are used in some religious ceremonies as purifying agents.

Etymology

First attested in English 1176, the word oil comes from Old French oile, from Latin oleum, which in turn comes from the Greek ἔλαιον (elaion), "olive oil, oil" and that from ἐλαία (elaia), "olive tree", "olive fruit". The earliest attested forms of the word are the Mycenaean Greek 𐀁𐀨𐀺, e-ra-wo and 𐀁𐁉𐀺, e-rai-wo, written in the Linear B syllabic script.

Oil (band)

Oil is a Christian thrash metal band from Long Beach, California, USA. The band was formed in 1997 by Ron Rinehart, the former vocalist with Dark Angel, who converted to Christianity at a Harvest Crusade after Dark Angel's dissolution in 1992. Other members include lead guitarist Blake Nelson (formerly with Deceiver, Desire and Captain Black) and drummer Jason Vander Pal. Oil has released two studio albums and one live album.

In 2004, Rinehart left the band to pursue other non-musical interests. The rest of the group is looking for a new vocalist.

Biography

Oil's first release was a self-financed EP in 1999.

The Refine album was well-reviewed for its honest, no frills metal approach. The band performed live gigs, including a show at the Stryper Expo, but Rinehart received an injury soon after the album release which meant Oil did not perform for nearly a year. Once recovered, Rinehart and Oil returned to performing, being announced as special guests to Disciple in April.

The band recorded a live album Choice Cuts Off the Chopping Block at the First Baptist Church in Downey, California, in November 2002. The record included two new acoustic songs, "This Is My Prayer" and "Medicine Man". When bass guitarist Matthew Joy opted out in May 2003, Oil recruited Jonathan Thiemens of Blind Sacrificies as a temporary replacement. This became permanent in July.

Annulus (mathematics)

In mathematics, an annulus (the Latin word for "little ring", with plural annuli) is a ring-shaped object, especially a region bounded by two concentric circles. The adjectival form is annular (as in annular eclipse).

The open annulus is topologically equivalent to both the open cylinder S¹× (0,1) and the punctured plane. Informally, it has the shape of a hardware washer.

The area of an annulus is the difference in the areas of the larger circle of radius R and the smaller one of radius r:

The area of an annulus can be obtained from the length of the longest interval that can lie completely inside the annulus, 2*d in the accompanying diagram. This can be proven by the Pythagorean theorem; the interval of greatest length that can lie completely inside the annulus will be tangent to the smaller circle and form a right angle with its radius at that point. Therefore, d and r are the sides of a right angled triangle with hypotenuse R and the area is given by:

The area can also be obtained via calculus by dividing the annulus up into an infinite number of annuli of infinitesimal width dρ and area 2πρ dρ and then integrating from ρ = r to ρ = R:

Annulus (mycology)

An annulus is the ring-like structure sometimes found on the stipe of some species of mushrooms. The annulus represents the remaining part of the partial veil, after it has ruptured to expose the gills or other spore-producing surface. An annulus may be thick and membranous, or it may be cobweb-like. An annulus may be persistent and be a noticeable feature of a mature mushroom, or it may disappear soon after the emergence of the mushroom, perhaps leaving a few remnants on the stipe as an "annular zone".

Annuli come in various shapes, which can be important features for identification of the mushroom. Common shapes include:

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Annulus (botany)

An annulus in botany is a single row of specialized cells on the outer rim of a fern sporangium that serves in spore dispersal. It consists typically of a ring or belt of dead water-filled cells with differentially thickened cell walls that stretches about two-thirds around each sporangium in leptosporangiate ferns. The thinner walls on the outside allow water to evaporate quickly under dry conditions. This dehiscence causes the cells to shrink and a contraction and straightening of the annulus ring, eventually rupturing the sporangial wall by ripping apart thin-walled lip cells on the opposite side of the sporangium. As more water evaporates, air bubbles form in the cells causing the contracted annulus to snap forward again, thus dislodging and launching the spores away from the plant. The type and position of the annulus is variable (e.g. patch, apical, oblique, or vertical) and can be used to distinguish major groups of leptosporangiate ferns.

Footnotes