Hydrocarbons and Oil Discovery Process

Physically and chemically diverse compounds primarily composed of hydrogen and carbon, existing in liquid, solid, or gaseous states.

Involves gravity and magnetic exploration, seismic surveying, processing seismic data, drilling potential wells, and evaluating well properties to locate and confirm oil reserves.

A rock that generates hydrocarbons.

A rock that stores hydrocarbons.

The amount of open space in a rock that can hold fluids.

The ability of a rock to allow fluids to flow through it.

Measured by Total Organic Content (TOC), indicating the amount of organic matter (expressed in weight %).

The potential of kerogen (insoluble organic matter) to generate hydrocarbons upon heat application

A measure of the richness of hydrogen in a rock, calculated as (S2/TOC) × 100. Higher HI suggests a rock is more likely to contain oil.

The maximum temperature a rock has been exposed to, indicating the stage of hydrocarbon generation.

The process of a source rock being covered by other layers of sediment, increasing pressure and temperature.

Conversion of organic material into hydrocarbons due to heat and pressure (catagenesis).

The temperature range (~60–120°C) where kerogen transforms into oil.

The ability of a cap rock to prevent hydrocarbons from leaking.

Overlying impermeable rocks that prevent hydrocarbons from escaping.

Chemical and physical changes in sediments due to burial and compaction, including compaction and cementation.

Increases in local temperatures from nearby igneous or volcanic activity, potentially leading to overmaturation.

A type of trap in which hydrocarbons are trapped in sand-filled channels surrounded by impermeable sediments, like a sealed container.

Uplift can bring source rocks closer to the surface, affecting their ability to generate hydrocarbons by changing their temperature and exposing them to weathering.

Erosion can physically remove sections of source rocks, reducing the amount of organic material available for hydrocarbon generation.

Uplift can cause reservoir rocks to compact, reducing their ability to hold oil due to decreased space and flow paths.

Erosion can remove the upper portions of reservoir rocks, leading to the loss of quality reservoir parts and exposing them to weathering.

Uplift can fracture or fault seals, potentially allowing trapped hydrocarbons to escape.

Erosion can physically remove sections of sealing layers, weakening their ability to contain hydrocarbons.

Uplift can deform and modify traps, potentially disrupting their ability to retain hydrocarbons.

Erosion can physically remove parts of a trap, leading to the loss of hydrocarbon accumulation and potential leakage.

The process where source rocks are heated to a suitable temperature for hydrocarbon generation.

Chemical and physical breakdown of rocks exposed at the surface, impacting their ability to generate hydrocarbons.

The reduction of porosity and permeability in rocks due to pressure from overlying sediments.

The process where a reservoir is uplifted and exposed to erosion, potentially reducing its capacity to store hydrocarbons.

When geological events, like burial or deformation, occur at the wrong time for hydrocarbon formation, leading to losses or inefficiencies.

When source rocks are heated beyond the optimal temperature range for oil generation, resulting in the formation of gas instead of oil.

Traps, which hold hydrocarbons, need to form before or during migration to effectively capture and preserve the oil or gas.

Tectonic events like folding or faulting should happen at the right time to create or enhance traps, without destroying existing reservoirs.

The timing of geological events, such as burial, deformation, and migration, is crucial for a successful hydrocarbon system. It affects the generation, migration, trapping, and preservation of hydrocarbons.

Natural breaks in rocks that allow fluids to flow more easily.

Fractures can significantly improve permeability in tight rocks, but excessive fractures can cause hydrocarbon leakage.

The Barents Sea contains various types of reservoirs, including sandstones, carbonates, fractured basement, and shale-associated reservoirs.

Sandstones from the Triassic period, found in fluvial-deltaic and shallow marine environments, with moderate to good porosity and permeability.

Sandstones from the Jurassic period, formed in shallow marine and deltaic settings, with excellent porosity and permeability.

Sandstones from the Cretaceous period, formed in deepwater and shallow marine settings, often with lower reservoir quality.

Carbonates from the Permian period, formed in shallow marine environments, often forming platforms and reefs, with variable porosity and permeability.

Carbonates from the Carboniferous period, including reefs and platform deposits, with reservoir potential depending on dolomitization and fracturing.

Hydrocarbon accumulations found in fractured crystalline basement rocks, with porosity and permeability entirely dependent on fractures.

Certain shales in the Barents Sea contain thin sandstone or siltstone units that can act as reservoirs.

The ability of a trap to hold hydrocarbons without leakage.

The trap must be completely sealed on all sides to prevent hydrocarbon escape.

A structural trap formed by the upward folding of rock layers, trapping hydrocarbons at the crest.

The specific temperature range where organic matter in source rocks converts into oil or gas. This range is typically 60-120°C for oil and higher for gas.

The time when source rock is buried deep enough to reach thermal maturity. This is crucial for hydrocarbon formation.

When the source rock is brought back up to the surface. This can affect the timing of hydrocarbon generation and the preservation of oil or gas.

The routes hydrocarbons take from the source rock to the reservoir rock. These paths must be open at the right time.

The formation of geological structures that capture and hold hydrocarbons. These structures must occur before or during the migration process.

The process of hydrocarbons filling a trap, leading to the accumulation of significant reserves. Timing matters!

The ability of a reservoir rock to store oil or gas. This depends on its porosity and permeability.

The creation of impermeable rocks that prevent hydrocarbons from escaping the reservoir. Timing matters!

When a petroleum system is pushed upward and exposed to weathering, potentially destroying traps and releasing hydrocarbons.

Tectonic movements that can crack and deform reservoir rocks, seals, and traps, possibly allowing oil to escape.

The rate at which a sedimentary basin is buried, impacting how quickly hydrocarbons are generated and retained.

The timing of various geological events (like uplift and erosion) affects whether oil or gas is preserved or lost.

A type of oil trap formed by folds or breaks in the earth's crust, creating compartments where oil can be trapped.