Chapter 3 Reading the Rocks - Saudi Aramco

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72 energy to the world : Volume one reading the rocks 73 golden corridor More than 60 percent of the world’s proven crude oil reserves and 40 percent of proven natural gas reserves lie in a 2,700-kilometer-long swath of the Middle East, which runs from eastern Turkey down through the Arabian Gulf to the Arabian Sea. senior Socal geologist, Max Steineke. Steineke, who had graduated from Stanford University in 1921 and had spent the previous 13 years working for Socal in a variety of remote locations, had asked to be transferred to the new operation in Saudi Arabia. He joined the other geologists in Bahrain, where they met to be ferried over to Jubail. Steineke was to lead a new third team of geologists in the field. Steineke’s colleagues soon recognized his acumen in understanding the sort of big-picture geology that was called for in exploring the huge concession. He was also a natural outdoorsman and expert marksman, which helped him earn the respect of the Bedouin soldiers and guides who accompanied the geological parties in the field. He was a rough-and-tumble “man’s man” with a face as weathered as a limestone outcropping, and hardly a stickler for details or a fancier of civilized ways. Steineke doggedly pursued evidence of a geological trend that might as well have been invisible as far as many of the geologists were concerned. Philip McConnell, who joined the production crews in Saudi Arabia in 1938, recalled that “Steineke knew the outlines of the great [al-Na‘lah or En Nala, as it was listed in geological records] anticline (the ‘Ghawar’ field) very early, and knew it might be one of the mightiest oil traps in the world. But he had a lot of German caution, almost to a fault—refused to commit himself in judgment until pushed.” Indeed, as early as the end of his first season in the field (spring 1935), Steineke and his partner, Tom Koch, had seen tantalizing hints in the heart of the concession area of what turned out to be the biggest oil field ever discovered—not just in Saudi Arabia but anywhere. “They described four other … highlands areas, at least one of which was definitely domed,” Casoc company records state, on which they said further work would be justified, but only if drilling on the Dammam Dome found oil in commercial quantities. mediterranean sea jordan iraq caspian sea While their recommendations for continued work in the region zeroed in on areas and structures that eventually were recognized as overlying the giant oil fields of Abqaiq, Qatif and Ghawar, marking a structure as worthy of study is far from finding firm evidence of oil. It took at least 15 years before company geologists fully appreciated the underground structures hinted at by the surface features Steineke and Koch identified and marked for further study in the spring of 1935 on their “to-do” list: 1. Drill a test on the El ‘Alat Dome. 2. Map Edh Duraiya, el Abqaiq and Qurain in detail. 3. Drill core holes or carry a seismograph survey across Tarut Island. 4. Investigate the highland southwest of Abqaiq. 5. Follow the En Nala monoclinal fold, lying west of Hofuf to the south and northwest to determine its origin. 6. Investigate the Ghawar area, lying west of Hofuf. 7. Introduce subsurface means of investigation to give geological information beneath the sand areas and the overlapping Miocene in certain localities. Casoc geologists Max Steineke and Bert Miller, drilling foreman Guy “Slim” Williams, construction foreman Walt Haenggi, left to right, and three unidentified colleagues pause as they look for the best site for the first well on the Dammam Dome. The well was “spudded” on April 30, 1935. key golden corridor Gas field oil field r e d s e a kuwait saudi arabia yemen united arab emirates a r a b g u l f o f o m a n oman i a n s e a Focusing on Dammam With geologists in the field and at headquarters in San Francisco agreeing that the Dammam Dome was the most promising site for drilling, plans for moving drilling materials and crews into Saudi Arabia began by late September 1934. With some pride, company officials noted the date they formally notified King ‘Abd al-‘Aziz of their drilling plans—only one year to the day after the first geologists had splashed ashore in Saudi Arabia. Mobilizing for the drilling program was not just a question of floating a rig across the Gulf from Bahrain and then hauling it through the sand and salt flats to the Dammam Dome site, as formidable as those challenges proved to be. Fred Davies, acting foreman of Bapco operations in Bahrain at the time, argued that the isolation of the site and the extreme summer heat required that the company undertake a dramatic housing program—a small town in the desert—far more elaborate than the bare minimum that might be the norm for such camp facilities. The initial community was to consist of living quarters, a cookhouse, a mess hall and a recreation room. In addition to these living and recreational quarters, an adequate number of offices and a geological laboratory were required. Finally, Casoc would also have to drill water wells, install its own plumbing system and build a power plant.
74 energy to the world : Volume one reading the rocks 75 “The Origin of Oil” A broad Middle Eastern corridor running roughly 2,735 kilometers from eastern Turkey down the Tigris and Euphrates river valleys and through the Arabian Gulf region contains more of the world’s proven oil reserves—about 60 percent—than any other place on Earth. It is not a coincidence. The combination of abundant marine life eons ago, giant tectonic plates deep in the Earth grinding into each other and subsequent faults and shifts in the Earth’s crust in the region has createed near-perfect conditions for forming and trapping crude oil and natural gas. Who better to tell the first chapter of this story than Chief Geologist Max Steineke? Writing in the October 21, 1945, issue of Oily Bird, as the company’s employee newspaper was called at the time, Steineke provided a primer on sedimentary geology titled “The Origin of Oil”: In almost all cases, the exact origin of oil is indeterminate, but where positive data is available on the subject, they invariably indicate a marine source, that is, close association with sediments that were originally deposited in the sea but later hardened into rocks. Furthermore, the scientists have found that the rocks producing petroleum are composed of a high percentage of small marine shells most of which are microscopic in size. Also, they have found that in many cases organisms similar to those occurring in rocks that have generated oil are now living in the sea and that these organisms living today contain minute globules of fatty substances from which petroleum-like material can be made in the laboratory. We have good evidence that the organisms found in the rocks that generated the Arabian oil lived approximately 150 million years ago. They evidently lived in a quiet sea or a somewhat enclosed basin vaguely similar to the Persian Gulf of today except that it was very much larger. As the organisms died they sank to the bottom forming layer upon layer until they formed a deposit hundreds of feet thick. These layers in turn were covered by thick deposits of mud, sand and shell beds, attaining a thickness of many thousands of feet. As the deposits were laid down, the sea bottom gradually subsided due to earth movements, which allowed a great accumulation of sediments with comparatively little change in the depth and character of the sea. As the overburden of later sediments mounted, the deeply buried ones near the bottom were naturally compressed, and they were also heated to hundreds of degrees in temperature due to the great depth. Because of the great pressure and heat applied to the sediments over a period of many millions of years the greater mass of deposits were hardened into rocks. During this change in the character of the deposits the fatty matter in the micro-organisms comprising a substantial portion of the sediments were changed by chemical processes into petroleum products of various types. Intensely salty water, and often brines, with which the sediments were saturated, may also have aided in the chemical reaction whereby the fatty globules in the minute organisms were changed to petroleum products. … If a porous rock formation containing water and oil is tilted, the oil will move up the incline. In the event the inclined bed is exposed at the surface due to earth movements and erosion there is nothing to stop the oil and gas from escaping to the surface and being lost by reaction with the atmospheric action throughout geological time. However, if this oil stratum is covered by dense impervious beds and is folded into wrinkles, the oil will migrate into the highest elevation possible in the bed originally containing the oil, but it will be stopped or trapped under the impervious layers. This trapped oil will stay in this position for countless millions of years. Since Steineke’s time, scientists have developed a much more detailed understanding of the forces that caused these thick layers of oil-bearing sediment to fold into wrinkles. Movements among giant, slowly shifting tectonic plates deep beneath the Earth’s crust have helped form today’s continents, and many large surface features such as mountain ranges often mark the edges along which one tectonic plate slips below or past another. About 90 million years ago, the Arabian tectonic plate collided with, and slowly began slipping under, the larger Eurasian plate to its north and east. That collision created the Zagros Mountains in Iran and the depression, hundreds of kilometers wide, lying parallel to the mountains to the west, which eventually filled in with the waters of the Arabian Gulf. Tension in the rocks created by the collision of two plates, as well as later shifting among rock layers underlying the region, led portions of the sedimentary layers to buckle upward, creating what are known as anticlinal folds that, if capped by impervious layers of rock, serve to trap hydrocarbons. Today’s Red Sea fills in a depression caused when a rift opened up in the Earth’s crust between Africa and Arabia about 36 million years ago. During the rift, the western side of the Arabian Peninsula was tilted upward and rose to almost three kilometers in elevation. It eroded down, over millions of years, into so-called “basement rocks” of igneous and metamorphic origin, which date back to the Precambrian era and range from 2 billion to 550 million years old. These rocks, forming what is known as the Arabian Shield, bulge eastward at the shield’s midriff and occupy about one-third of the peninsula. More recent lava flows in some areas have spread across these older shield rocks. The shield slopes gradually eastward and is covered in the eastern two-thirds of the country by younger sedimentary rocks called the Arabian Shelf. These are the rocks Steineke described as forming beneath ancient shallow seas during the late Jurassic Period, when dinosaurs roamed the Earth. Chief Geologist Max Steineke stands in Wadi Nisab atop exposed limestone dating from the Eocene geologic period. In the Eastern Province, then known as the al-Hasa region, Eocene rock is typically buried beneath hundreds of feet of relatively younger sedimentary layers. When found on the surface, it may indicate the presence of subterranean folds in the rock capable of trapping oil.
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Chapter 3 Reading the Rocks - Saudi Aramco

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