In the oil and gas industry, the midstream sector focuses on the transportation, storage, and initial processing of hydrocarbons after extraction (upstream) and before refining or distribution (downstream). Below are the key phases and stages of midstream for oil and gas:

1. Transportation

Transportation is one of the main activities in midstream and varies depending on the type of hydrocarbon (oil or gas).

For oil:

• Pipelines:

  • Networks of pipelines that transport crude oil from production fields to refineries or terminals.

  • Require pumping stations to maintain flow.

• Maritime transport (Tankers):

  • Tanker ships that transport crude oil from maritime terminals to refineries or international markets.

• Rail or truck transport:

  • Used in areas without pipeline infrastructure or for short distances.

For gas:

• Pipelines:

  • Networks of pipelines that transport natural gas from production fields to processing plants or distribution centers.

  • Require compression stations to maintain pressure.

• LNG (Liquefied Natural Gas) transport:

  • Gas is cooled to -162°C to convert it into liquid, reducing its volume for easier transport via LNG carriers.

  • At the destination, it is regasified for distribution.

2. Storage

Storage is essential to manage fluctuations in supply and demand.

For oil:

• Storage tanks:

  • Onshore facilities that store crude oil before transport or refining.

  • Located at terminals, ports, or near refineries.

• Underground storage:

  • Use of salt caverns or depleted reservoirs to store large volumes of crude oil.

For gas:

• Underground storage:

  • Depleted reservoirs, aquifers, or salt caverns are used to store natural gas.

  • Helps manage seasonal demand (e.g., higher consumption in winter).

• Cryogenic tanks:

  • Used to store LNG in liquid form.

3. Initial Processing

Hydrocarbons often require initial processing before transport or distribution.

For oil:

• Fluid separation:

  • Removal of water, gas, and sediments from crude oil.

• Stabilization:

  • Reduction of volatile components to make crude oil safe for transport.

For gas:

• Processing at gas plants:

  • Removal of impurities (CO2, H2S, water) to meet quality specifications.

  • Separation of natural gas liquids (NGLs: ethane, propane, butane).

• Liquefaction:

  • Conversion of natural gas into LNG for international transport.

4. Distribution

Distribution connects midstream with downstream, delivering hydrocarbons to refineries, chemical plants, or end markets.

For oil:

• Distribution to refineries:

  • Transport of crude oil to refineries for processing into derivatives (gasoline, diesel, etc.).

• Export terminals:

  • Shipping points for international crude oil sales.

For gas:

• Distribution to gas networks:

  • Transport of processed gas to distribution networks for residential, commercial, or industrial use.

• Regasification:

  • Conversion of LNG back into natural gas for injection into distribution networks.

5. Key Infrastructure

• Pipelines: Extensive networks connecting production areas with processing and distribution centers.

• Processing plants: Facilities to treat and purify hydrocarbons.

• Storage and export terminals: Strategic points for managing oil and gas flows.

• Ships and trains: Alternative transport methods for areas without pipeline infrastructure.

6. Midstream Challenges

• Infrastructure investment: High construction and maintenance costs for pipelines, processing plants, and storage facilities.

• Regulation and permits: Compliance with environmental and safety regulations.

• Operational flexibility: Managing supply and demand fluctuations.

• Security: Protecting infrastructure from physical and cyber risks.

In summary, midstream is a critical link in the oil and gas value chain, responsible for the transportation, storage, and initial processing of hydrocarbons, ensuring their efficient flow from production fields to end markets.