Au reservoir: A guide to new oil discoveries

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Many of you have read the article in the Houston Chronicle where  BP announced they have found 3 billion barrels of crude oil off the coast of Texas. Many of us instantly think, how do they find that oil? How do they determine how much oil is there? And how does that compare with other fields around the world?

So, I thought I’d answer some of those questions. Companies find oil fields by using many different types of scientists and surveying tools. Geologists and geophysicists (two types of scientists that really rock) use a variety of surveying methods such as 3D and 4D seismic scans, magnetic surveys, and gravity surveys. All of these scans and surveys help them to examine rock cores to see what the permeability and porosity of the formations are. These are not the only scientists or tools used for oil fields, but they are some that are mentioned in our Wiess Energy Hall.

Taladro
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Once the scientists think they know where the oil will be, a test well is drilled. If oil is found in the rock formation, then the scientists go back to the seismic data to see how large the formation is. They will drill more wells (well, well, well) to find more information on the formations such as where the oil comes into contact with the water. They will also go back to the core sample to look at the characteristics of the rock the oil was found in.

Now that they have found the oil and looked at the characteristics of the reservoir, how do they estimate the number of barrels of oil? There are the proven reserves which is the amount of oil that the scientists are sure of getting out of the field using current methods. The unproven reserves are the amount oil that the scientists think are there but cannot be reached yet.

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But how does that new field off the coast of Texas rate with the others in the world? Well, its not the biggest. That award goes to the Ghawar field in Saudi Arabia. It is estimated that the field has 71 billion barrels of oil. Saudi Arabia claims to have over 200 billion barrels of oil in its fields, while America, before this new discovery, claimed to have 21 billion barrels of oil still in its fields. But what it really comes down to is production; or how many barrels of oil does a field produce a day. The Ghawar field produces 5 million barrels a day! The world produces 80 million barrels a day. America only produces 5 million barrels a day but uses 19 million barrels a day. Most of which is used for gasoline (America uses about 378 million gallons a day.)

So the scientists use a variety of surveying methods to find oil fields and to determine their size. The new find off the coast of Texas increases America’s crude oil reserves by 33%, but what will really matter is how much the new field can be made to produce. (How much crude could a crude field churn out if a crude field churns out crude?)