The Origin of Oil

Basic Oil Geology

Oil deposits are usually found in sedimentary rocks. Such rocks formed as sand, silt, and clay grains were eroded from land surfaces and carried by moving water to be deposited in sediment layers. As these sediment layers dried, chemicals from the water formed natural cements to bind the sediment grains into hard rocks.

Pools of oil are found in underground traps where the host sedimentary rock layers have been folded and/or faulted. The host sedimentary or reservoir rock is still porous enough for the oil to accumulate in spaces between the sediment grains. The oil usually hasn’t formed in the reservoir rock but has been generated in source rock and subsequently migrated through the sedimentary rock layers until trapped.

The Origin and Chemistry of Oil

Most scientists agree that hydrocarbons (oil and natural gas) are of organic origin. A few, however, maintain that some natural gas could have formed deep within the earth, where heat melting the rocks may have generated it inorganically.1 Nevertheless, the weight of evidence favors an organic origin, most petroleum coming from plants and perhaps also animals, which were buried and fossilized in sedimentary source rocks.2 The petroleum was then chemically altered into crude oil and gas.

The chemistry of oil provides crucial clues as to its origin. Petroleum is a complex mixture of organic compounds. One such chemical in crude oils is called porphyrin:

Petroleum porphyrins … have been identified in a sufficient number of sediments and crude oils to establish a wide distribution of the geochemical fossils.3

They are also found in plants and animal blood4 (see sidebar Porphyrins).

The Significance of Oil Chemistry

It is very significant that porphyrin molecules break apart rapidly in the presence of oxygen and heat.5 Therefore, the fact that porphyrins are still present in crude oils today must mean that the petroleum source rocks and the plant (and animal) fossils in them had to have been kept from the presence of oxygen when they were deposited and buried. There are two ways this could have been achieved:

1. The sedimentary rocks were deposited under oxygen deficient (or reducing) conditions.6

2. The sedimentary rocks were deposited so rapidly that no oxygen could destroy the porphyrins in the plant and animal fossils.7

However, even where sedimentation is relatively rapid by today’s standards, such as in river deltas in coastal zones, conditions are still oxidizing.8 Thus, to preserve organic matter containing porphyrins requires its slower degradation in the absence of oxygen, such as in the Black Sea today.9 But such environments are too rare to explain the presence of porphyrins in all the many petroleum deposits found around the world. The only consistent explanation is the catastrophic sedimentation that occurred during the worldwide Genesis Flood. Tons of vegetation and animals were violently uprooted and killed respectively, so that huge amounts of organic matter were buried so rapidly that the porphyrins in it were removed from the oxidizing agents which could have destroyed them.

The amounts of porphyrins found in crude oils vary from traces to 0.04% (or 400 parts per million).10 Experiments have produced a concentration of 0.5% porphyrin (of the type found in crude oils) from plant material in just one day,11 so it doesn’t take millions of years to produce the small amounts of porphyrins found in crude oils. Indeed, a crude oil porphyrin can be made from plant chlorophyll in less than 12 hours. However, other experiments have shown that plant porphyrin breaks down in as little as three days when exposed to temperatures of only 410°F (210°C) for only 12 hours. Therefore, the petroleum source rocks and the crude oils generated from them can’t have been deeply buried to such temperatures for millions of years.

The Origin & Rate of Oil Formation

Crude oils themselves do not take long to be generated from appropriate organic matter. Most petroleum geologists believe crude oils form mostly from plant material, such as diatoms (single-celled marine and freshwater photosynthetic organisms)12 and beds of coal (huge fossilized masses of plant debris).13 The latter is believed to be the source of most Australian crude oils and natural gas because coal beds are in the same sequences of sedimentary rock layers as the petroleum reservoir rocks.14 Thus, for example, it has been demonstrated in the laboratory that moderate heating of the brown coals of the Gippsland Basin of Victoria, Australia, to simulate their rapid deeper burial, will generate crude oil and natural gas similar to that found in reservoir rocks offshore in only 2–5 days.15

However, because porphyrins are also found in animal blood, it is possible some crude oils may have been derived from the animals also buried and fossilized in many sedimentary rock layers. Indeed, animal slaughterhouse wastes are now routinely converted within two hours into high-quality oil and high-calcium powdered and potent liquid fertilizers, in a commercial thermal conversion process plant16 (see sidebar Animal Wastes Become Oil).

Conclusion

All the available evidence points to a recent catastrophic origin for the world’s vast oil deposits, from plant and other organic debris, consistent with the biblical account of earth history. Vast forests grew on land and water surfaces17 in the pre-Flood world, and the oceans teemed with diatoms and other tiny photosynthetic organisms. Then during the global Flood cataclysm, the forests were uprooted and swept away. Huge masses of plant debris were rapidly buried in what thus became coal beds, and organic matter generally was dispersed throughout the many catastrophically deposited sedimentary rock layers. The coal beds and fossiliferous sediment layers became deeply buried as the Flood progressed. As a result, the temperatures in them increased sufficiently to rapidly generate crude oils and natural gas from the organic matter in them. These subsequently migrated until they were trapped in reservoir rocks and structures, thus accumulating to form today’s oil and gas deposits.