# Conventional oil and gas production: Techniques

Desert wells, North Sea platforms and drillships in deep water

Source page: https://www.materialinsights.org/energy/e_oil_gas_conv/techniques/

What this tab covers The methods used to capture this energy: how each works, and how they compare on efficiency, cost, life-cycle emissions, maturity and scale.

Conventional oil and gas flows from porous rock to a well without the rock being fractured. It is produced from onshore wells, shallow-water platforms and deepwater rigs with floating production vessels. Offshore fields supply about 30% of world oil.

#### Comparison

| Method | Efficiency | Cost | Life-cycle emissions | Maturity | Scale |
|---|---|---|---|---|---|
| **Onshore conventional wells**^[1](https://www.spe.org/en/industry/increasing-hydrocarbon-recovery-factors/)^[7](https://ogj.com/general-interest/economics-markets/article/55171807/rystad-energy-cost-of-new-upstream-oil-projects-rises-further)^[8](https://doi.org/10.1126/science.aar6859)^[10](https://www.ipcc.ch/site/assets/uploads/2018/02/ipcc_wg3_ar5_annex-iii.pdf)^[6](https://woa.un.org/third-world-ocean-assessment/socioecological-systems/sustainable-and-inclusive-ocean-economy/chapter-3-subchapter-3b-offshore-hydrocarbons) | Recovery up to about 20% (primary), typically 35-45% with injection | Breakeven about USD 27 per barrel (Brent) for new onshore Middle East projects (2024) | Upstream average 10.3 g CO2e per MJ of crude (global, 2015); gas power about 490 g CO2e/kWh life-cycle (IPCC median) | mature | About 70% of world oil comes from onshore, conventional and unconventional together (calculated from the 30% offshore share) |
| **Offshore shelf platforms**^[2](https://www.ogj.com/drilling-production/production-operations/ior-eor/article/17227761/global-oil-reserves-1-recovery-factors-leave-vast-target-for-eor-technologies)^[7](https://ogj.com/general-interest/economics-markets/article/55171807/rystad-energy-cost-of-new-upstream-oil-projects-rises-further)^[6](https://woa.un.org/third-world-ocean-assessment/socioecological-systems/sustainable-and-inclusive-ocean-economy/chapter-3-subchapter-3b-offshore-hydrocarbons) | North Sea fields average about 46% recovery | Breakeven about USD 37 per barrel for new shelf projects (2024) | Similar to onshore; lower where platforms are powered from shore | mature | Offshore in total supplies about 30% of world oil |
| **Deepwater rigs and floating production**^[7](https://ogj.com/general-interest/economics-markets/article/55171807/rystad-energy-cost-of-new-upstream-oil-projects-rises-further)^[6](https://woa.un.org/third-world-ocean-assessment/socioecological-systems/sustainable-and-inclusive-ocean-economy/chapter-3-subchapter-3b-offshore-hydrocarbons) | No separate figure in our sources | Breakeven about USD 43 per barrel for new deepwater projects (2024) | No separate figure in our sources | mature | About 7% of world oil and gas production, but about half of conventional discoveries in the past decade |

Large onshore Middle East fields are the cheapest oil in the world because a few high-pressure wells drain huge reservoirs. Offshore projects cost more to build but compete: Rystad rates new deepwater barrels (USD 43) cheaper than US shale (USD 45) or oil sands (USD 57). Upstream emissions are small next to combustion, but flaring and leaks matter: the most carbon-intensive producers emit nearly twice the world average per MJ.

#### How each method works
**Onshore conventional wells**

A rig drills through rock into a reservoir capped by an impermeable seal and lines the hole with cemented steel casing. Reservoir pressure, then pumps, lift oil and gas to the surface, where they are separated from water. As pressure falls, water or gas is injected through other wells to keep oil flowing.^[1](https://www.spe.org/en/industry/increasing-hydrocarbon-recovery-factors/)^[7](https://ogj.com/general-interest/economics-markets/article/55171807/rystad-energy-cost-of-new-upstream-oil-projects-rises-further)^[8](https://doi.org/10.1126/science.aar6859)^[10](https://www.ipcc.ch/site/assets/uploads/2018/02/ipcc_wg3_ar5_annex-iii.pdf)^[6](https://woa.un.org/third-world-ocean-assessment/socioecological-systems/sustainable-and-inclusive-ocean-economy/chapter-3-subchapter-3b-offshore-hydrocarbons)
**Offshore shelf platforms**

Fixed steel or concrete platforms stand on the seabed in shallow water and carry drilling rigs, processing plant and accommodation. Oil is exported by pipeline or tanker.^[2](https://www.ogj.com/drilling-production/production-operations/ior-eor/article/17227761/global-oil-reserves-1-recovery-factors-leave-vast-target-for-eor-technologies)^[7](https://ogj.com/general-interest/economics-markets/article/55171807/rystad-energy-cost-of-new-upstream-oil-projects-rises-further)^[6](https://woa.un.org/third-world-ocean-assessment/socioecological-systems/sustainable-and-inclusive-ocean-economy/chapter-3-subchapter-3b-offshore-hydrocarbons)
**Deepwater rigs and floating production**

Drillships or semi-submersible rigs drill in water deeper than about 400 m. Wellheads sit on the seabed, linked by risers to floating production, storage and offloading vessels or tension-leg platforms.^[7](https://ogj.com/general-interest/economics-markets/article/55171807/rystad-energy-cost-of-new-upstream-oil-projects-rises-further)^[6](https://woa.un.org/third-world-ocean-assessment/socioecological-systems/sustainable-and-inclusive-ocean-economy/chapter-3-subchapter-3b-offshore-hydrocarbons)

#### Sources

1. [Increasing Hydrocarbon Recovery Factors (Zitha, Felder, Zornes, Brown and Mohanty)](https://www.spe.org/en/industry/increasing-hydrocarbon-recovery-factors/) Society of Petroleum Engineers, 2011
2. [Global Oil Reserves 1: Recovery factors leave vast target for EOR technologies (Sandrea and Sandrea), field-database review](https://www.ogj.com/drilling-production/production-operations/ior-eor/article/17227761/global-oil-reserves-1-recovery-factors-leave-vast-target-for-eor-technologies) Oil & Gas Journal, 2007
3. [Third World Ocean Assessment, Chapter 3, Subchapter 3b: Offshore hydrocarbons](https://woa.un.org/third-world-ocean-assessment/socioecological-systems/sustainable-and-inclusive-ocean-economy/chapter-3-subchapter-3b-offshore-hydrocarbons) United Nations, 2025
4. [Rystad Energy: Cost of new upstream oil projects rises further](https://ogj.com/general-interest/economics-markets/article/55171807/rystad-energy-cost-of-new-upstream-oil-projects-rises-further) Oil & Gas Journal, 2024
5. [Global carbon intensity of crude oil production (Masnadi et al., Science 361(6405): 851-853)](https://doi.org/10.1126/science.aar6859) Science (AAAS), 2018
6. [Climate Change 2014: Mitigation of Climate Change, Annex III: Technology-specific cost and performance parameters (Table A.III.2, life-cycle emissions)](https://www.ipcc.ch/site/assets/uploads/2018/02/ipcc_wg3_ar5_annex-iii.pdf) IPCC Working Group III, 2014

## Other sections

- [Summary](https://www.materialinsights.org/energy/e_oil_gas_conv/index.md)
- [Overview](https://www.materialinsights.org/energy/e_oil_gas_conv/overview/index.md)
- [Correlation](https://www.materialinsights.org/energy/e_oil_gas_conv/correlation/index.md)
- [Efficiency](https://www.materialinsights.org/energy/e_oil_gas_conv/efficiency/index.md)
- [Resources and labour](https://www.materialinsights.org/energy/e_oil_gas_conv/resources/index.md)
- [Impact on the biosphere](https://www.materialinsights.org/energy/e_oil_gas_conv/biosphere/index.md)
- [Relationships](https://www.materialinsights.org/energy/e_oil_gas_conv/links/index.md)