The Birth of Petroleum Geological Science
Contributed by Mark Mau and Henry Edmundson.
During the early days, there were still plenty of oil seepages to show the driller where to place his rig. But that’s where the knowledge stopped. Azeri and US drillers alike had little awareness of the rock strata they were about to penetrate, let alone the formations that they hoped would contain oil. The science of rock or oil didn’t exist then, although the foundations had been laid almost 100 years before.
The Roots of Petroleum Geology
In 1795, James Hutton, an all-round talent from Edinburgh who had studied medicine and worked as a chemical manufacturer and farmer, published his “Theory of the Earth; or an Investigation of the Laws observable in the Composition, Dissolution, and Restoration of Land upon the Globe.” Hutton had taken to roaming the Scottish landscape and found himself drawn to riverbeds, ditches, borrow pits, coastal outcrops and inland cliffs, wondering what great scheme lay behind them. It was punishing work collecting rocks as he once stated, “Lord pity the arse that’s clagged to a head that will hunt stones.”
The origins of petroleum were not so easily resolved, although many at the time correctly suspected oil was contained in sedimentary rocks. Belsazar de la Motte Hacquet, a native of France and a physician, swept up by the Seven Years’ War and deposited in the mining town of Idrija, Slovenia, became an authority on salt mines and the oil and gas commonly found in them. In 1793, he attributed the origin of petroleum to marine animal matter. This was substantiated five years later by the English chemist Charles Hatchett. Based on laboratory studies of bitumen extracted from seeps in Trinidad, Hatchett suggested in 1798 that these heavy oils were simply decomposed plant and animal matter. As for James Hutton, he postulated in his “Theory of the Earth” that petroleum was distilled from coal.
In the bigger scheme of things, Hutton was the first to grasp the full significance and immensity of geologic time. He demonstrated that the hills and mountains of the present day are far from everlasting but have themselves been sculpted by slow processes of uplift and erosion—processes that are ongoing today. The self-made geologist observed that the sedimentary rocks on the earth’s crust bore all the hallmarks of having accumulated exactly like those being deposited in the present. The vast thickness of sedimentary rocks, he surmised, spoke of cycles of erosion and sedimentation for periods of time that could only be described as inconceivably long. In other words, what one can see as rocks and structures on the surface today is in fact something in motion, originating not tens or hundreds of years ago but tens or hundreds of millions of years ago.
Hutton’s ideas were too profound for general comprehension by his contemporaries and gained few adherents until Charles Lyell arrived on the scene. In the late 1820s and early 1830s, the lawyer-turned-geologist wrote the seminal “Principles of Geology: Being an Attempt to Explain the Former Changes in the Earth’s Surface, by References to Causes now in Operation.” The three-volume work was essentially Hutton’s theory, supported by the great wealth of observations that Lyell had made in his homeland Scotland as well as in England and Continental Europe. Charles Lyell crucially popularized James Hutton’s geologic concepts and boiled them down to the memorable line: “The present is the key to the past.”
With these broad principles established, the next step was unraveling the sequence of geologic ages and dating them. The first step had been taken in 1669 when Niels Stensen, better known as Steno, a Danish anatomist and later a Catholic bishop, surmised the superposition principle that says that a rock layer overlying another is always younger than the layer below. The first to use this principle was William Smith, nicknamed the “Father of English Geology,” who mapped stratigraphic layers observed in canal excavations across England, eventually making the first geologic map of England in 1815.
The naming of rock strata came from everywhere. The Cambrian derived from a classical name for Wales. The Ordovician and Silurian were named after ancient Welsh tribes, because they were identified from stratigraphic sequences in Wales. The Devonian was named for the English county of Devon. The succeeding Carboniferous was named after the ubiquitous occurrence of coals within its sequences, while the Permian was named after the ancient kingdom of Permia by Sir Roderick Murchison during his extensive travels in Russia in the mid-19th century.
The Triassic was named in 1834 by the German geologist Friedrich August von Alberti from the three distinct layers of reddish sedimentary deposits found throughout northwest Europe. The Jurassic was named by French chemist, mineralogist and zoologist Alexandre Brongniart for the extensive marine limestone exposures of the Jura Mountains. The Cretaceous, from Latin creta meaning “chalk,” was defined by Belgian geologist Jean Baptiste Julien d'Omalius d'Halloy in 1822 from observations of the extensive chalk beds in the Paris basin.
Dating rock strata, however, proved elusive. In 1841, William Smith’s nephew, John Phillips, made a first attempt by combining Steno’s depositional rule with observations of fossils found in various strata. Phillips’s timescale provided a broad framework featuring epically long periods of geology, such as Paleozoic ("old life" from Cambrian to Devonian, 540 to 250 million years), Mesozoic ("middle life" from Triassic to Cretaceous, 250 to 66 million years) and Cenozoic (“recent life” from 66 million years to the present), formerly known as the Tertiary period.
The new discipline of geology was soon embraced outside Europe. Canada’s Geological Survey was founded in 1842 by Montreal-born William Edmond Logan, who came from the mining business with deep knowledge of coal deposition. He had also traveled to the oil springs in Gaspé, Quebec, “Here the connexion is evident between the oil springs and undulations of the strata which form the accumulation of the petroleum.”
Elsewhere, geologists were making similar observations. In 1855, an Anglo-Irish geologist, Thomas Oldham, working in Burma, pointed out that the oil from the Yenangyuang field, then being produced from wells dug by hand, was connected with the highest part of an upfold—or anticline—in the earth’s strata. In the US, Ebenezer Baldwin Andrews, both priest and geologist, reported in 1861 that in western Virginia the productive wells were closely associated with the axial area of anticlines.
Both Oldham and Andrews had hit the anticline jackpot. Over millions of years, compression and tension of the earth’s crust folds the rock layers, occasionally forming uplifts or anticlines that can often be recognized at the surface. Oil, being lighter than water, moves upward, and as long as the uplift is sealed with a layer of impermeable rock the oil gets trapped, resulting in a reservoir of oil-filled porous rock.
Although Andrews became known as the father of the anticlinal theory, another American, Thomas Sterry Hunt, a geologist and chemist who had been an assistant to William Logan since 1846, made similar observations in western Ontario. Just two months after the publication of Andrews’s western Virginia report, Hunt reported that oil finds made at Enniskillen, western Ontario, were likewise associated with a broad, moderately folded anticline. Later, exploration around Petrolia, a stone’s throw from Eniskillen, resulted in a gusher.
The anticlinal theory thus became the backbone of oil geology, and it remained of crucial importance for many oil and gas discoveries in the 20th century. The first successful wildcat in the Middle East, at Masjid-i-Sulaiman in Persia in 1908, was located on an anticline. Thirty years later, in the classic textbook “Fundamentals of the Petroleum Industry,” the US geologist Dorsey Hager stated unequivocally that “the anticlinal theory is as fundamental to the geologist as Newton’s gravitational law is to the physicist.”
Salt domes and Spindletop
The other geologic idea of the era centered on underground salt domes, a concept that would precipitate an oil boom on the US Gulf coast at the beginning of the 20th century. This brought John Dustin Archbold, a senior executive of Standard Oil, to a tight spot when he promised to drink every gallon of oil produced west of the Mississippi River, the dividing line between known areas of oil production such as Pennsylvania, east of the great river, and the rest of the US, which had produced nothing. A key figure in this oil boom was Patillo Higgins, a self-taught geologist who lived near Beaumont in southeast Texas. Noting gas seepages that were emerging from a small hillock called Spindletop on the flat plain, Higgins began reading more about the infant science of geology. A paper by Israel White of the West Virginia Geological Survey that he read in the summer of 1892 convinced him that Spindletop was an anticline.
During the next six years, Higgins drilled six wells, found nothing, and ended up heavily in debt. In a last-ditch attempt, he advertised for someone to help his drilling enterprise and recruited Captain Anthony Francis Lucas. Lucas had moved to the US from Austria, where he had studied engineering and then spent time in the navy. Lucas knew about drilling, but luckily for Higgins he also knew about salt. Earlier in 1893, Lucas had taken a job with Myles and Company of New Orleans, superintending operations at a salt mine owned by the Avery family at Petite Anse, Louisiana, 30 miles south of Lafayette, now known as Avery Island. When exploring for salt on Avery Island, Lucas had found sulfur and traces of oil and gas. He had in fact stumbled upon a second type of geologic structure harboring oil and gas—the salt dome. The salt Lucas found was from the Jurassic age that in patches underlies the Gulf of Mexico and most of its coastal region. Salt is lighter than most rock, so over geologic time, these patches rise dome-like, distorting the overlying rock layers and creating traps that can accumulate hydrocarbons. In 1896, Lucas moved his salt explorations to Jefferson Island and the following year to Belle Isle, both in Louisiana, where he again found sulfur, oil and gas. Speaking later of his Belle Isle explorations, he wrote, “This led me to study the accumulation of oil around salt masses, and I formed additional plans for prospecting other localities. Thus I began my investigations into the occurrence of oil on the Coastal Plain.”
By the time Lucas started working for Higgins at Spindletop, he had enough confidence to convince Higgins that it was salt domes and not anticlines that were worth investigating. His reasoning resulted in one of the most famous oil gushers in history, Spindletop, in 1901. Ten years later, the salt dome concept was well accepted in the Gulf region, counting 36 explored salt domes and 10 oil fields in southeast Texas and Louisiana and giving rise to a huge regional oil industry. Neither Higgins nor Lucas nor any other explorer of the time, however, had the technical means to find the remaining hundreds of salt domes hidden around the margins of the Gulf of Mexico. This would become possible only with the development of modern geophysics two decades later. During that time, drilling went through a minor revolution.
This entry is based on Groundbreakers: The story of oilfield technology and the people who made it happen, by Mark Mau and Henry Edmundson. You can find the book at www.fast-print.net/bookshop/1791/groundbreakers.