Upstream
Exploration, appraisal and production focus on understanding and developing subsurface resources.
Petroleum & energy / Knowledge
The energy system, explained.
Clear, practical guides to the terminology and decisions that connect petroleum resources, infrastructure and products.
Explore the topicIn perspective
A more informed view of energy.
The petroleum value chain encompasses several distinct disciplines. Understanding how they connect provides useful context for the decisions involved at every stage.
Key disciplines
Understanding the work.
Explore the disciplines and decisions that shape this part of the energy system.
Midstream
Gathering, storage and transportation connect production with processing and markets.
Downstream
Refining and distribution turn crude oil and other inputs into products used across the economy.
Operational integrity
Equipment condition, procedures and risk controls matter across the lifecycle of an asset.
Closer look
Five stages, many connected decisions.
Every asset follows a context-specific path, but its lifecycle can be understood through broad stages: assess, design and develop, operate, maintain and improve, and close.
- AssessDevelop an understanding of the resource, technical context and risks.
- Operate and maintainMonitor systems, manage change and care for equipment throughout use.
- ClosePlan for decommissioning and applicable site obligations.
In context
Questions worth asking.
Explore the practical concepts behind the work.
What is a petroleum value chain?
It is a way to describe interconnected activities from finding resources through production, transportation, refining and distribution.
What are petroleum products?
Examples include fuels, lubricants and feedstocks. Products are produced through processing and refining hydrocarbon inputs.
Why does methane matter?
Methane can be emitted from oil and gas systems. Detection, measurement and repair can support efforts to reduce emissions.
What is decommissioning?
It is the planned process of taking infrastructure out of service and addressing associated obligations in accordance with applicable requirements.
Energy glossary
Find the right words.
Search straightforward definitions for the concepts used across the petroleum value chain.
Showing all terms
Appraisal
The evaluation of a discovery to gather additional information about its characteristics and potential.
Blending
Combining components to produce a product that meets an intended specification.
Crude oil
A naturally occurring mixture of hydrocarbons that has not yet been refined.
Decommissioning
The planned process of taking infrastructure out of service and addressing relevant closure obligations.
Distillation
A separation process that sorts components into fractions based on their boiling ranges.
Downstream
Activities that can include refining, processing, distribution and marketing of petroleum products.
Exploration
The search for oil and natural gas resources using geological, geophysical and well information.
Feedstock
A material supplied to a process as an input for producing other materials or products.
Gathering
The collection and movement of production from wells toward processing, storage or transportation systems.
Mechanical integrity
Ongoing attention to the condition of equipment through inspection, testing, maintenance and correction of deficiencies.
Methane
A hydrocarbon gas and the principal component of natural gas; it can be emitted from oil and gas systems.
Midstream
The gathering, storage and transportation activities connecting production with processing and markets.
Petroleum products
Materials produced from crude oil and other hydrocarbon inputs, including fuels, lubricants and feedstocks.
Process safety
The management of hazards associated with processes involving hazardous materials to prevent or mitigate serious incidents.
Seismic survey
A survey that uses reflected energy to help interpret the structures and layers beneath the surface.
Upstream
Activities associated with exploration, appraisal, development and production of oil and gas.
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Further reading
Go deeper.
Explore technical background from independent public sources.