Potrero del Llano Numero Quatro, Huasteca Region, Eastern Mexico; 1914
The rough meaning of that in English is venting gas. The photo is courtesy of the Ben Manning Collection at the DeGolyer Library at Southern Methodist University and, for a student of early Mexican oil history, a great find worth sharing.
One can assume these were all good problems to have, even in 1914, but Aquila's production hands must have literally been on the brink of a heart attack, constantly. So large was the flow rates from this well that any restrictions in the well head and capping assembly caused the production casing to want to lift completely out of the ground. The mere placement of production pipelines caused enough head/back pressure to breach the production casing shoe and oil and gas blew hard, up thru the ground in a half dozen areas. One of these surface breeches occured in a river bank and was gauged to be upwards of 15,000 BOPD. Lightning hit that surface breech and set it on fire. Eventually a dam was built downstream to contain the oil. An estimated 1 MM BO was actually then burned off the river.
And, if all this was not enough to worry over, revolutionists were always taking shots at the wellhead, trying to ignite it
After the lightning strike, the Potrero 4 well itself was literally almost covered in dirt, with a large, earthen levee like berm around it, the fear of lightning actually striking the well bore itself was so great. This earthen berm was replaced with a sort of concrete dome over the top of the wellhead as seen in the photo above.
While the fire in the river embankment raged on, efforts were made to open the well itself and eliminate any restrictions in the downstream gathering system. The idea was that this would prevent more surface breaches.
In this photo we can see large OD flowlines coming out of the protective, concrete dome venting enormous amounts of associated gas. All of this was encircled in a protective fence, with guard towers at each corner to watch for revolutionists. All of the vent stacks seen in the photo are from this one, single well and are helping to blow off pressure.