Up-Stream

Background

The upstream sector of the petroleum industry is concerned with the exploration and production of oil and natural gas. It includes activities such as:

• Geophysical and geological surveys to find oil and gas reserves.
• Drilling exploration wells to determine the presence and extent of hydrocarbon deposits.
• Developing and constructing oil and gas fields to extract the reserves.
• Operating and maintaining production facilities to produce and transport the oil and gas to market.

Examples of upstream activities include offshore drilling, onshore drilling, hydraulic fracturing, and tar sands extraction. Companies that operate primarily in the upstream sector include Exxon-Mobil, BP, and Chevron. These companies are responsible for finding and producing the raw materials that are later processed and refined into gasoline, diesel, jet fuel, and other petroleum products by companies in the downstream sector.

Geophysical and geological surveys are techniques used to explore and study the subsurface of the Earth to locate and assess the presence of oil and natural gas deposits. Geophysical surveys use a variety of methods to generate data about subsurface geological features. For example:

• Seismic surveys use shock waves to produce images of subsurface rock formations and help identify areas that may contain oil or natural gas.
• Gravity surveys measure variations in the Earth's gravity field to identify subsurface geological features.
• Magnetic surveys measure variations in the Earth's magnetic field to identify subsurface geological features.

Geological surveys involve the study of rock samples, well logs, and other data to understand the subsurface geology and identify areas that may contain oil or natural gas. This information is used in combination with geophysical data to develop a more complete understanding of the subsurface environment. These surveys are crucial to the exploration and production of oil and natural gas, as they provide information about the location and characteristics of potential reservoirs, which helps companies to decide where to drill exploration wells and how to develop production facilities.

Oil and natural gas reserves are extracted from underground reservoirs using various techniques, depending on the specific conditions at the site. Some common methods include:

• Drilling: A well is drilled into the reservoir to allow oil and natural gas to flow to the surface. This is the most common method of extraction and is used in both onshore and offshore operations.
• Hydraulic fracturing (fracking): A mixture of water, sand, and chemicals is injected into a well under high pressure to create fractures in the rock that release oil and natural gas. This method is used primarily in the extraction of unconventional oil and gas, such as shale gas.
• Steam injection: Steam is injected into heavy oil reservoirs to reduce the viscosity of the oil and make it easier to extract.
• In situ thermal recovery: A heat source, such as steam or solvents, is used to warm the oil, reducing its viscosity, and making it easier to extract.

Once the oil and natural gas have been extracted, they are processed and transported to market for refining and distribution. The specific extraction method used will depend on the characteristics of the reservoir, such as its depth, pressure, temperature, and the properties of the oil or natural gas. After oil and natural gas have been extracted from the ground, they must be processed and transported to market for refining and distribution. The specific processing and transportation methods will depend on the characteristics of the product, as well as local regulations and infrastructure. Oil processing typically involves the removal of impurities, such as water and salts, to produce a refined product that can be transported and sold. This is usually done at an oil processing facility near the production site.

Natural gas is often processed to remove impurities and to recover any natural gas liquids (NGL's), such as propane and butane, that are present. This is done at a natural gas processing plant. The processed natural gas is then transported to market via pipelines, which can cover hundreds or thousands of miles. Oil and natural gas can also be transported by tanker ships for long distances, especially for international trade. The product is loaded onto tankers at terminals near the production site and transported to refineries or other processing facilities, where it is processed and distributed to customers.

Production

The top 10 oil fields, globally, in terms of production are:

1. Ghawar Field, Saudi Arabia
2. Burgan Field, Kuwait
3. Rumaila Field, Iraq
4. Zuluf Field, Saudi Arabia
5. Marjan Field, Saudi Arabia
6. Safaniya Field, Saudi Arabia
7. Kuwait Field, Kuwait
8. Shaybah Field, Saudi Arabia
9. Manifa Field, Saudi Arabia
10. Al-Shaheen Field, Qatar

In the United States, the largest oil fields, by production are:

1. Permian Basin, Texas, and New Mexico
2. Eagle Ford Shale, Texas
3. Bakken Formation, North Dakota, and Montana
4. Anadarko Basin, Oklahoma, and Texas
5. Williston Basin, Montana, and North Dakota
6. DJ Basin, Colorado
7. Marcellus Shale, Pennsylvania, and West Virginia
8. Haynesville Shale, Texas, and Louisiana
9. Niobrara Shale, Colorado, Wyoming, and Nebraska

The Permian Basin is currently the largest producing oil field in the US, with significant reserves of both conventional and unconventional oil. The shale formations in Texas and North Dakota have also become major producers of oil in recent years, due to advances in hydraulic fracturing and horizontal drilling technologies. These fields have helped to make the US a major player in the global oil market and have contributed to the growth of the country's domestic energy production.

Reserves

The top 15 countries with the largest proven oil reserves are:

1. Venezuela
2. Saudi Arabia
3. Canada
4. Iran
5. Iraq
6. Kuwait
7. United Arab Emirates
8. Russia
9. Libya
10. Nigeria
11. United States
12. Algeria
13. Angola
14. Kazakhstan
15. Brazil

The ranking of oil reserves can change over time as new reserves are discovered or as changes in technology or market conditions make previously uneconomical reserves recoverable. Additionally, the size of a country's oil reserves does not necessarily correspond to its level of oil production, as factors such as political stability, infrastructure, and investment also play a role in determining a country's ability to extract and produce oil.