hydrocarbon kitchen, Oil & Gas Glossary

What Is a Hydrocarbon Kitchen?

Hydrocarbon kitchen (also called the generative kitchen, oil kitchen, or mature source rock fairway) is the geographic area within a sedimentary basin where source rock has been buried deeply enough and heated sufficiently to generate and expel hydrocarbons. The expelled oil and gas then migrate updip or laterally through carrier beds to charge reservoir rocks in nearby structural or stratigraphic traps. Identifying and mapping the kitchen is a fundamental step in petroleum systems analysis, allowing explorationists to assess whether a basin contains an active charge system and to rank prospects by proximity to and volume of the generating kitchen.

Key Takeaways

A kitchen exists where source rock has reached sufficient thermal maturity: roughly 60 to 120 degrees Celsius for oil generation (vitrinite reflectance 0.6 to 1.3% Ro) and 120 to 200 degrees Celsius for gas generation (1.3 to 3.5% Ro).
Kitchen geometry is reconstructed using 1D and 2D basin modeling, which simulates burial history, heat flow, and the temperature-time integral experienced by the source rock through geological time.
Hydrocarbons expelled from the kitchen migrate through permeable carrier beds and faults, losing volume to migration losses before reaching a trap; kitchen volume and migration efficiency determine the charge available to fill a prospect.
A large, well-defined kitchen with short migration distances and efficient migration pathways is a key positive indicator in play fairway analysis and exploration ranking.
Deep basin kitchens may have passed through the oil window into the gas window, shifting the expected product from oil to wet gas or dry gas with increasing depth and temperature.

How the Hydrocarbon Kitchen Works

Organic-rich source rocks contain kerogen, the solid organic matter that transforms into oil and gas when heated. As a basin subsides and sediment accumulates, source rocks are progressively buried to greater depths where geothermal gradient raises their temperature. The transformation of kerogen to hydrocarbons is a kinetically controlled series of chemical reactions that proceed faster at higher temperatures; the concept of thermal maturity quantifies how far this transformation has progressed. Below the oil window, source rock is immature and retains its organic matter. Within the oil window (roughly 60 to 120 degrees Celsius), liquid hydrocarbons are generated and expelled. In the gas window (above 120 to 150 degrees Celsius), previously generated oil cracks to gas, and gas-prone kerogens generate dry gas directly.

Once generated, hydrocarbons must be expelled from the fine-grained source rock into adjacent permeable carrier beds through primary migration. Expulsion efficiency varies by kerogen type and source rock characteristics, typically ranging from 20 to 80 percent of generated hydrocarbons. After entering the carrier bed, secondary migration carries hydrocarbons updip along permeable pathways under buoyancy forces, with losses to residual saturation along the migration path. The fraction that reaches and fills a trap is the charge efficiency, and the product of kitchen volume, generative yield, expulsion efficiency, and charge efficiency determines the volume available to fill prospects. Exploration risk is greatly reduced when a kitchen can be mapped with confidence, migration pathways can be traced, and timing of generation relative to trap formation can be established.

Fast Facts: Hydrocarbon Kitchen

Oil window temperature: Approximately 60 to 120 degrees Celsius
Oil window maturity: Vitrinite reflectance 0.6 to 1.3% Ro
Gas window temperature: Approximately 120 to 200 degrees Celsius
Gas window maturity: Vitrinite reflectance 1.3 to 3.5% Ro
Typical geothermal gradient: 25 to 35 degrees Celsius per kilometer of burial
Expulsion efficiency: 20 to 80% of generated hydrocarbons expelled from source rock
Basin modeling tool: 1D PetroMod or BasinMod (single well); 2D for basin cross-section
Key kitchen indicator: Total organic carbon (TOC) greater than 1% with Ro greater than 0.6%

Field Tip:

When evaluating a frontier basin, always check whether the kitchen is currently active (still generating) or has been spent. A kitchen that reached peak generation in the Cretaceous and has since been uplifted and cooled may have generated large volumes but those hydrocarbons are ancient; the critical question is whether sufficient traps existed at the time of generation to capture them. Timing of trap formation relative to kitchen activity is one of the most commonly overlooked risk elements in petroleum systems analysis.

Petroleum Systems Framework and Kitchen Mapping

The petroleum system is the genetic link between a source rock kitchen and the accumulations it charges. The five essential elements are source rock, reservoir rock, seal rock, trap, and overburden rock (to drive burial and heating); the two critical processes are generation-expulsion-migration and trap formation. All five elements and both processes must be present and properly timed for an accumulation to exist. Mapping the kitchen is therefore the first step: without an active or once-active generative area, the remaining elements are irrelevant. Geochemical analysis of oil samples and source rock extracts (biomarkers, carbon isotopes, diamondoids) can fingerprint which kitchen charged which accumulation, providing direct evidence of migration pathways and petroleum system connectivity across a basin.

Kitchen mapping integrates seismic interpretation of basin structure, well-calibrated thermal maturity data (vitrinite reflectance, apatite fission track, programmed pyrolysis Tmax), and heat flow models derived from regional geology. In basins with multiple source rock intervals at different depths, different kitchens may be active at different times and at different locations, requiring separate petroleum system analyses for each source-reservoir pair. Three-dimensional basin models extend this analysis across the full basin volume, predicting the spatial distribution of generated volumes and migration vectors that guide prospect ranking and well location decisions.

Migration Distance, Losses, and Kitchen-to-Trap Efficiency

Hydrocarbons migrating from the kitchen to a distant trap lose volume at every step. Residual saturation in carrier beds typically traps 3 to 8 percent of migrating hydrocarbons per kilometer of path length in tight carriers, more in water-wet systems with low relative permeability to hydrocarbons. Fault-controlled migration can be efficient over hundreds of kilometers in well-connected fault systems, but can also disperse charge if faults are too numerous. The fill-spill behavior of relay structures along the migration path can create satellite accumulations that reduce the charge reaching the primary prospect. As a practical rule, prospects within 50 kilometers of a well-defined kitchen along a clear updip migration pathway carry lower charge risk than prospects requiring migration of 200 or more kilometers through uncertain carrier geometry.

Hydrocarbon kitchen is also referred to as:

generative kitchen — emphasizes that the area is actively or has been actively generating hydrocarbons
mature source rock fairway — highlights the geographic belt where source rock has entered the maturity window
oil kitchen or gas kitchen — distinguished by whether the dominant product is liquid or gas based on thermal maturity
charge area — used in risk assessment to describe the region contributing hydrocarbons to a specific prospect or play

Frequently Asked Questions About Hydrocarbon Kitchens

Can a kitchen be exhausted or spent?

Yes. A source rock kitchen that has generated and expelled most of its available kerogen is described as spent or overmature. Once kerogen is converted to hydrocarbons and expelled, it cannot regenerate. In highly overmature rocks (vitrinite reflectance above 3.5% Ro), even gas generation has ceased. Uplifted basins that were once deeply buried may have active kitchens in their geological past but are no longer generating today. Identifying whether a kitchen is currently active versus spent is critical for understanding the timing of charge relative to trap formation.

How is the kitchen boundary mapped in a frontier basin?

In a frontier basin with few or no wells, the kitchen boundary is estimated from 1D basin models calibrated to any available well data (vitrinite reflectance, fluid inclusion temperatures), extrapolated using seismic-derived depth maps of the source rock interval and regional heat flow estimates from geophysical data. Magnetic and gravity data can constrain basement depth and heat flow. Analog basins with similar tectonic settings provide additional calibration. The uncertainty on kitchen boundaries in frontier basins is significant, typically plus or minus 20 to 50 kilometers, and reducing this uncertainty is a primary objective of early exploration drilling.

What is the difference between a kitchen and a depocentre?

A depocentre is the area of maximum sediment accumulation in a basin, where the sedimentary section is thickest. A kitchen is the area where source rock has reached thermal maturity for hydrocarbon generation. The two often overlap because thicker burial in the depocentre drives higher temperatures and maturity, but they are not the same. Source rock may be mature in a depocentre but immature on the basin margins where burial is shallower. Conversely, high heat flow from volcanic or geothermal activity can mature source rocks at relatively shallow depths far from the depocentre.

Why Hydrocarbon Kitchens Matter in Oil and Gas

The location and volume of the hydrocarbon kitchen is the most fundamental control on whether commercial accumulations can exist in a basin. No amount of excellent reservoir quality, effective sealing, or elegant structural trapping makes a difference if there is no kitchen to charge the system. Exploration programs that fail to first define the kitchen geometry and confirm kitchen activity risk drilling into structurally valid but uncharged prospects, a mistake that has cost billions of dollars in frontier basin exploration history. Conversely, basins with large, well-defined, currently active kitchens and clear migration pathways to mapped traps represent the most de-risked exploration targets available, justifying the highest exploration investment and the most aggressive development timelines.

Hydrocarbon Kitchen: The Source of Oil and Gas in a Sedimentary Basin