The U-Boats and Venezuelan Oil

Reuters ran an article in July 2020 about Venezuelan oil production, stating that it was at its lowest level since 1943. The collapse is an indictment of the government policies that have resulted in social and economic devastation in Venezuela, and decimated the production of oil by the state-owned oil company, PDVSA. Oil production also suffered in 1942 and 1943 for a different reason - the German U-Boat campaign in the Caribbean Sea. This campaign was directed against the supply of crude oil and refined products such as gasoline and lubricating oil to the US and Britain. The Germans well understood the critical role of oil in a 20th Century war machine, and the strategic importance of disrupting the supply. Lacking any military resources on the western side of the Atlantic Ocean, their U-Boat fleet provided them with an opportunity to interrupt the supply of this vital resource to the Allies.

Someone interested in the U-Boats of World War II might wonder why the waters off of Venezuela might be a priority target for the German fleet, rather than operating closer to home in the waters off of Great Britain or in the Mediterranean. The U-Boat attacks on the North Atlantic convoys have been the subject of countless books and movie, including a new film starring Tom Hanks in 2020. The U-Boat campaigns in the Caribbean Sea and the Gulf of Mexico are less well known. The Venezuelan campaign required a voyage of 4000 miles from the U-Boat base in Lorient, France, to reach the Venezuelan coastline and begin the raiding. Understanding why this assault occurred when and where it did necessitates a look at the geology and geography of Venezuela, and the infrastructure of the oil industry there in 1942.

As the map above shows, Lake Maracaibo is a large brackish lake situated in the western part of Venezuela, close to the border with Colombia. It is connected to the open water of the Caribbean Sea by a narrow passage which connects to the shallow waters between the coastline of South America and the islands of Curacao and Aruba. The city of Maracaibo is located on the southern end of this passageway, between the open waters of the lake and the mountains of Colombia. The city today is a mix of high rise buildings, old Spanish architecture, classic buildings from the early 20th century, and terrible slums. The geography of Lake Maracaibo resembles that of to Lake Pontchartrain in Louisiana - a brackish estuary where fresh waters from rivers flowing into the lake mix with seawater pushed in by tidal flow. The water in Lake Maracaibo is relatively shallow - only 15 feet deep or less for the most part. Aside from the city of Maracaibo, most of the shoreline of Lake Maracaibo is marshy and undeveloped.

Sedimentary rocks have been deposited for millions of years in Lake Maracaibo, the mud and sand washed down from the adjacent highlands. Buried to a depth where the temperature rises to a level conducive for the formation of crude oil, the sediments formed some of the largest oilfields in the world. The oil reservoirs are found below the lake bottom, and the size of the reservoirs, easily developed in the shallow water, made them attractive candidates for development with the technology available in the early twentieth century. They were initially developed in the 1920s, mostly by Standard Oil (now Exxon Mobil) and Royal Dutch Shell. Platforms supporting derricks and production facilities dotted the lake and are still ubiquitous today. The prolific fields and huge investments by Standard Oil and Shell increased oil production so that by the 1940s, Venezuela was the third largest producer in the world. The shallow water of the lake prevented large tankers from entering the lake, so the crude oil was carried by small tankers to large refineries on the islands of Aruba (Standard Oil) and Curacao (Shell), situated a few miles off the coast of Venezuela. Both were Dutch colonies at the beginning of the war. The crude oil was refined into gasoline, lubricating oil and other products, then shipped north in larger tankers, primarily to the United States. The total dependence on tanker, both to transport crude oil to the refineries on Aruba and Curacao and subsequently to carry the refined products north, made the Venezuelan oil production particularly vulnerable to U-Boat assaults at the beginning of 1942.

The German U-Boat Admiral, Karl Donitz, recognized the opportunity to have a disparate impact on the war by a relatively small force. Five U-Boats were dispatched to the area from Lorient, France in February of 1942 in a campaign called Operation Neuland. The smaller tankers that crossed the shallow shelf between the entrance to Lake Maracaibo and the Dutch Islands were particularly vulnerable, and 17 were sunk in the first four weeks of the campaign. The red lines on the map shows the course that the tankers had to take leaving Lake Maracaibo, a path which left them no room to avoid the waiting submarines. The U-Boats also attempted to shell the refineries on Aruba and Curacao, which terrified the inhabitants but inflicted little real damage.

A second wave of U-Boats left France the following month, continuing the destruction. Tanker traffic between the oilfields in Lake Maracaibo and the refineries came to a half. The result was that Shell and Standard Oil were forced to shut in Lake Maracaibo production, reducing total Venezuelan production from approximately 600,000 barrels per day to 400,000 barrels per day, a level not seen since the depths of the depression. Oil production did not return to pre-war levels until 1944, when American anti-submarine defenses improved to the point where the U-Boat assault was greatly diminished, although not entirely halted. Attacks on the larger tankers carrying refined products from the islands to the United States also took place, especially in the second and third waves of the attack.

The U-Boat assault on the tankers carrying Venezuelan oil took place simultaneously with the attacks on tankers carrying crude oil from the fields in Texas and Louisiana to the northeastern United States. The improvement in anti-submarine warfare, along with the construction of pipelines and the discovery of new fields in Florida and elsewhere, greatly reduced by impact on crude oil supplies by 1944. But a relatively small number of U-Boats had an enormous impact on the Allied oil supply for much of 1942 and 1943.

I visited both Maracaibo and Curacao years ago when I worked for Shell. The history, scenery, and people of both places are wonderful, and I look forward to returning to Venezuela again someday. In the meantime, the story of my next novel takes place in Venezuela during World War II. It should be published sometime early next year.