Hydrocarbons and petrochemical industry:

DefinitionPetroleum:

Crude petroleum is a heterogeneous mixture of various hydrocarbons (molecules composed of carbon and hydrogen atoms), unusable as they are. Its components must be separated in order to obtain the final products that are directly exploitable. There are generally two major types :

  • Energy products, such as gasoline, diesel, or oil;

  • Non-energy products, such as lubricants, bitumen, and naphtha, are used in petrochemistry.

The origin of petroleum :

The origin of petroleum is linked to the geological processes that occurred millions of years ago. Petroleum is a fossil fuel, and its formation involves the decomposition and transformation of organic matter from ancient marine organisms.

The basic steps in the origin of petroleum are as follows:

Organic Material Accumulation: In ancient seas and oceans, marine organisms such as plankton, algae, and other microscopic organisms lived and died. When these organisms died, their remains settled at the bottom of the ocean, accumulating over time.

Sedimentation and Pressure: As more layers of sediment accumulated over the organic remains, the lower layers experienced increased pressure from the weight of the overlying sediments. This pressure, combined with the lack of oxygen in the deep layers, prevented the complete decomposition of the organic matter.

Temperature and Heat: Over millions of years, the buried organic material underwent a process called diagenesis, where heat and pressure increased due to the deep burial. The temperature in the Earth's crust causes the organic material to undergo chemical transformations.

Formation of Kerogen: The organic material transforms into a waxy, solid substance known as kerogen during this process. Kerogen is an intermediate stage in the formation of petroleum.

Catagenesis: With continued heat and pressure, kerogen undergoes further transformation in a process known as catagenesis. This process involves breaking down the complex organic molecules into simpler hydrocarbons, which eventually form liquid and gaseous hydrocarbons.

Migration and Accumulation: The generated hydrocarbons, including oil and natural gas, move through the porous rock layers in the Earth's crust in a process called migration. These hydrocarbons can accumulate in reservoir rocks, forming what we know as oil and gas deposits.

Trapping: The hydrocarbons become trapped in geological structures such as anticlines, fault traps, or salt domes. This trapping prevents the petroleum from migrating further and creates reservoirs of economically viable quantities of oil and gas.

Exploration and Extraction: Humans discover and extract petroleum deposits through exploration activities such as seismic surveys and drilling. Once found, wells are drilled into the reservoirs, and the petroleum is brought to the surface for processing and use.

"It's important to note that the entire process of petroleum formation takes millions of years, and the conditions required for its formation are specific to certain geological environments. The extraction and use of petroleum as an energy resource have profound implications for the global economy and the environment."

Oil refining

  • Oil refining is an industrial process that transforms crude oil into different products such as gasoline, heavy oil or naphta.

  • Refining consists of separating the various oil cuts and transforming them into intermediate and commercial products.

Exploitation of hydrocarbons

Four stages in the process of mining hydrocarbons:

  1. Production : (Extraction - Drilling - Off shore)

  2. Transport: (Oil Pipeline, Gaz pipeline, pumping or compression station)

  3. Processing: (Refining: extracting by-products; Liquefaction)

  4. Exploitation & Marketing