Harry Hess, left, was a geologist and geophysicist of some fame in the 1950's when he created the American Miscellaneous Society (not kidding). His colleagues in the Society were of a like mind to drill a well to the earth's crust, something called the Mohorovičić, or 'Moho," a thick barrier believed to overly the earth's molten mantle.
The moho is actually quite thick and deep under major land masses but in parts of the Pacific Ocean it becomes shallower, and much thinner and a within reach of conventional rotary drilling methods. Because these scientists in the Miscellaneous Society were mostly from California, they picked a spot off the beach in San Diego in a deep trench where the mud line was 11,000 feet below sea level, but the m0ho was uplifted. The plan was that it might be a good idea to drill this well in the ocean if they happened to drill the well thru the crust and blew molten lava everywhere, you know, to kind of keep things a little cooler. I suppose the thinking was the worse case scenario would be a new chain of islands similar to Hawaii.
The scheme was called Project Mohole. They raised money thru various Federal entities, including the National Science Foundation, leased a really good drill ship, one of the first of its kind with self-stabilizing thrust necessary for dynamic positioning ( built in 1957 by Gulf Oil) and spudded the well in March of 1961. This was a really big deal and many referred to the project as something akin to going to the moon.
The drill ship was actually a retrofitted barge that had a hole in the middle of it. A deck was built on top of the barge to support the draw works, pipe yard, pumps, etc. It was called the USN CUSS. The renown author, John Steinbeck, facing us in the center of the above photograph, below, was hired by Life Magazine to do this story and he described the CUSS drill ship as having "the sleek race lines of an outhouse standing on a garbage scow."
The CUSS may have looked like Porta Potty on a sled but it was designed with a then unique, dynamic positioning system that kept the drill shit centered over the hole by use of propellers. This new technology was advanced over the decades and is now used extensively in semi-submersible drill rigs (Deepwater Horizon) and drill ships (Deepwater Invictus) properly positioned over subsea blowout preventer stacks.
Five wells were drilled in the project by the CUSS, all in over 11,600 feet of water; that in itself was remarkable given the era. No risers were used, nor subsea BOP's. There were numerous drilling problems associated with drill pipe buckling and severe dog legs (deviations) from vertical, etc. The deepest penetration below the mud line was only 600 feet, a long way from the actual Moho.
Using tried and true technology developed in Texas and Louisiana' oil and natural gas exploration, over 460 feet of full hole cores were cut and taken from the deepest well in what geologists determined to be Miocene aged rocks.
When trips were made out of the hole with these cores the entire ship crew, from cooks and bed makers to off duty rig hands and geologists all showed up on deck to watch the cores being carefully taken from the core barrels.
The depths of Miocene aged rocks could not be reached from California onshore fields and paleontologists had a field day, for decades, studying these cores for fossils imbedded within the core sediments. Numerous papers have been written about these Mohole cores and led to some rather remarkable proof of climate changes over geological time, how often over millions of years those changes occured, then disappeared, reoccurred then disappeared again. It also proved theories of plate tectonics in an unstable California coastline.
Careful breaking out (unscrewing) core barrel segments full of goodies with the rig floor packed with interested onlookers.
Right, removing cores from the core barrel.
Project Mohole proved to be an expensive ($35MM) bust for not reaching the mantle above the earth's core and received much ridicule from the non-science world, and particularly US politicians that claimed it was a big waste of money, which politicians are experts on. Brown and Root, the project coordinators, got a lot of flack for how the wells were engineered and for the most part the entire idea, however valid, was met with constant criticism and skepticism.
Though many scientists around the world wanted Project Mohole to go on to its second phase of drilling deeper tests, the funding for that second half never occurred and the entire expedition was eventually canned.
President John F. Kennedy, however, telegrammed the rig crew..." a remarkable achievement and an historic landmark in our scientific and engineering progress.”
John Steinbeck's' articles for Life Magazine are very enlightening and fun to read; if you are interested they are easy to find on the internet, all you have to do is GTS it. GTS in my household stands for "google that shit."
Steinbeck joked that when he stayed on the CUSS to write the article he always asked the cook in the morning for his eggs to be cooked over easy, and the cook would always respond, "look, Mr. John, this tub rolls so much I can barely keep eggs in the skillet, best take them scrambled, sir."
John Steinbeck became a big fan of the Mohole Project and was terribly disappointed that its second phase never came about. So disappointed he supposedly wrote a sort of caustic letter to Congress for pulling the funding.