This is 21 gravity (API) crude oil that is dark green and very sweet (<0.4% sulfur). It has a viscosity at 105 degrees F (BHT) of 5.6 cP. Its characteristics are similar to a well known South Texas oil posting called "Mirando," which hardly anybody under the age of 45 even remembers anymore. It is very high in lubricant qualities and at one time was shipped by barge from S. Texas to New Jersey to make "3 and 1" oil. At other times over the past 80 years this oil was actually refined in San Antonio and used for printers ink in the newspaper industry. Now it receives a bit of a premium over WTI prices simply because it can be blended with high gravity shale oil.
This crude oil has actually been "fingerprinted," so to speak, as having origins in the Eagle Ford shale some 6,000 feet deeper than the depth of its current accumulations. It was "cooked" in the Eagle Ford shale kitchen (Cretaceous Epoch, 80MM years old), escaped and migrated up subsurface fault planes into structural traps at shallower depths. There it was "weathered," or altered, by 38 million years (Eocene Epoc) of contact with fresh water and slightly below gradient bottom hole temperatures. Its beautiful stuff, this oil, and smells absolutely delightful. Catherine refuses to wear a dab of it behind her ear on special occasions, however.
Before any crude oil can be sold it must meet standards for basic sediments and water (BS&W) content. The maximum allowance for BS&W is 1% by volume.
The above photo is a sample of crude oil and formation water as it comes directly out of the ground. The percentage of oil to water (OWR) appears to be close to 60% but there is more water bound in the oil, as well as minor solids, mostly formation clays and/or silt. Those "unwanted" components of the production stream have to be treated on the surface and removed before the oil can be sent into sales tanks.
Before calling the crude oil buyer to haul this oil off lease, to a pipeline connection, it is the responsibility of the lease operator (gauger) to test it. He or she does so by "catching" 3 samples in top, middle and bottom of the sales tank with something called a "thief." A mutual solvent is then added to the sample, it is heated to +100 degrees F and then spun-out in a centrifuge to check for BS&W content. In both the cone tubes, above (middle and bottom samples) that content appears to be 1/10 of 1% and is good to go! The crude oil buyer will recheck these oil conditions itself before putting the oil on the truck and driving off with it, using the same test standards. Its paying the oil operator for oil, not water, and does not want any of its crap. Crude oil buyers must meet 1% BS&W standards as the oil goes thru a LACT unit and into the pipeline. 1% limits are very common throughout the industry and the standardization starts upstream with the operator.
Watching crude oil trucks drive out the cattleguard, fully loaded with 80 million year old oil, is always sort of a proud moment. Finding something THAT stinking old, and then getting it out the ground, is pretty cool.