Oil Field Glossary

I have made a start albeit a small start on the oil field glossary. I will add to this over the coming weeks and months.

http://www.glossary.oilfield.slb.com/

OIL GLOSSARY
Oil API gravity
The API gravity of oil is basically a measurement of how heavy the oil is. Oil with an API of less than 10 sinks in water and is like a tar like substances. Oil with an API of more than 10 floats on water. The API of the oil at 330a is around 18 and is considered quite heavy. What most will be looking for when ERH release what the API is will be around the 29 - 32 API. But in saying that all oil is good oil. For more info on API please see http://en.wikipedia.org/wiki/API_gravity

Porosity
is a measure of the void spaces in a material. Something that has the porosity of 1 is basically solid like solid granite. Vuggy or vug porosity basically means large holes or even caves. So to put porosity in layman's terms it means how easily a liquid can pass through a material. The higher the porosity the easier it can pass through due to the void space. Anything more than 28% porosity is considered vuggy.For more info on porosity please seehttp://en.wikipedia.org/wiki/Porosity

Stock tank barrels
Standard Volumes vs. Actual Volumes
Epicentre makes a distinction that is often glossed over in the oil industry. That is the distinction between volumes and standard volumes. A volume of (for example) oil could be measured in cubic metres (m3). (Whatever is said about "oil" also holds true for "gas".) Cubic metres is the SI unit of volume. More generally, it can be measured in barrels (bbl), which, in Epicentre, is a customary unit of measure.
But there is another unit of volume: the stock tank barrel (stb). Consider an experiment in which a given amount of oil is cooled (or heated) to 60 degF, and brought to atmospheric pressure. The original volume of oil is altered (usually reduced) to a different volume, due primarily to the removal of dissolved gas. This new volume is called a standard volume. The SI unit for a standard volume (introduced by POSC) is standard cubic metres at 15 degC (scm15C), and the customary unit is the stock tank barrel (stb60).
The initial reaction is to consider the scm15C to be another form of m3. I.e., they are both units of volume, and a distinction should not be made between them. This view fails for two reasons:
1. A given amount of oil can have a volume different from the standard volume.
2. There is no conversion between the volume and the standard volume. The conversion depends on the particular oil sample.
Thus, the standard volume really is a different quantity type, and requires a different unit of measure.

spudding
"spudding" means the very start of drilling on a new well. The American Petroleum Institute offers the following definitions using the word spud:
Spud Contractor Name
The name of the contractor spudding the well.

Spud Date
The day when the drilling bit penetrates the surface utilizing a drilling rig capable of drilling the well to the authorized total depth.

Spud Time
The actual time (hours and minutes) when the drilling bit penetrates the surface utilizing a drilling rig capable of drilling the well to the authorized depth.

Spudding In
The very beginning of drilling operations of a new well.

Permeability
The ability, or measurement of a rock's ability, to transmit fluids, typically measured in darcies or millidarcies. Formations that transmit fluids readily, such as sandstones, are described as permeable and tend to have many large, well-connected pores. Impermeable formations, such as shales and siltstones, tend to be finer grained or of a mixed grain size, with smaller, fewer, or less interconnected pores. Absolute permeability is the measurement of the permeability conducted when a single fluid, or phase, is present in the rock. Effective permeability is the ability to preferentially flow or transmit a particular fluid through a rock when other immiscible fluids are present in the reservoir (for example, effective permeability of gas in a gas-water reservoir). The relative saturations of the fluids as well as the nature of the reservoir affect the effective permeability. Relative permeability is the ratio of effective permeability of a particular fluid at a particular saturation to absolute permeability of that fluid at total saturation. If a single fluid is present in a rock, its relative permeability is 1.0. Calculation of relative permeability allows for comparison of the different abilities of fluids to flow in the presence of each other, since the presence of more than one fluid generally inhibits flow.