This stands for oil country tubular goods and refers to the group of steel tube products (both seamless and welded) used in vertical oil well applications such as casing, drill pipe, and well tubing.

An offtake agreement would occur between a producer and a buyer to purchase or sell products that are yet to be produced. It is normally negotiated before the construction of a factory or facility to secure a market and revenue stream for its future output. Offtake agreements are typically used to help the selling company acquire project financing for future construction, expansion projects, or new equipment through the promise of future income and proof of existing demand for the goods.

A mixture of liquid hydrocarbons of different molecular weights.

Drilling mud with which crude oil has been unintentionally mixed. 

An oil field is a geographic area under which an oil reservoir lies. An oil field consists of a reservoir in a shape that will trap hydrocarbons and that is covered by an impermeable or sealing rock. 

An estimated measure of the total amount of oil contained in a reservoir. 

A strip-mining process involving the removal and subsequent processing of tar sand from shallow reservoirs containing heavy, viscous oil.

A mud in which the external phase is a product obtained from an oil, such as diesel oil or mineral oil.

A producing well with oil as its primary commercial product. Oil wells almost always produce some gas and frequently produce water. Most oil wells eventually produce mostly gas or water.

The process of making steel by heating the metal in the hearth of a regenerative furnace. Heat is supplied from a large, luminous flame over the surface, and the refining takes seven to nine hours. 

Ore is natural rock or sediment that contains one or more valuable minerals, typically containing metals, that can be mined, treated and sold at a profit.

Ore is extracted from the earth through mining and treated or refined, to extract the valuable metals or minerals. The grade of ore refers to the concentration of the desired material it contains. The value of the metals or minerals a rock contains must be weighed against the cost of extraction to determine whether it is of sufficiently high grade to be worth mining, and is therefore considered an ore. 

Organic coating describes the paint or varnish which is applied as an extra corrosion protection layer to products typically made from zinc-coated sheet.

An oxidising atmosphere contains sufficient oxygen to combine, or oxidise, with certain other elements if they are present. An oxidising atmosphere is key to the success of the basic oxygen steelmaking process for converting liquid pig iron into steel. Oxygen is blown through the molten iron in the BOF vessel, where it combines with and removes unwanted carbon as carbon monoxide and carbon dioxide.