48 Million Years Old
We washed these fossils from a well this morning; picked them out of the returns to the rig tank after circulating bottoms up. They are from the producing interval in this well, or more likely from marine shale overlying the producing sand...Tertiary, Eocene in age and something in the order of 48 million years old. This morning was the first time these little darlings have seen the light of day in a long time. The look metallic; they aren't. They are like little shells you would pick up on a beach. They are no bigger than they lead on the end of a pencil.
The deposition of these little fossils were associated with a regressive, shallow shoreline that moved back and forth for millions of years. The sea would recced and leave mudstones deposited on the sea floor that then cooked and compressed into shale; then sea levels would rise again over geological time, the tide would come in, so to speak, for several thousand years, and deposit clean sand between the layers of shale that were rich. Then the sea would recced again; rinse repeat over a 600 foot correlative interval that probably lasted 10 million years. Oil cooked in source beds, below, found a way to migrate into these clean sand beds and where there was a trap, a seal against controlling faults, for instance, the oil stayed....for 35-56 million years. Guys like Mikey came along and find the oil in these sand reservoirs.
Does that make me feel a little...special? A little, yeah,
All good oil men care deeply where their oil was sourced, how it migrated into traps, what, if any, are the fingerprints for this oil that makes its migration traceable, how the earth turned and made this all happen. Its meaningful. We want to understand because in doing so we become better oilmen. We are humbled by the entire matter, I assure you.
We also, most of us anyway, care where are all goes after it drives out the cattleguard, what refinery uses it and what it does with it, who the end use is. Some of my oil was onced used for newspaper printer's ink, some was barged around to New Jersey for high end lubricants; now, proudly, it stays in Texas and is used for lubricant feed stock. I am proud my oil stays in America, for Americans.