Upstream Oil and Gas Glossary: Terms Every Professional Must Know

Step into an oil and gas meeting and you will most likely encounter a score of acronyms even before you have taken a sip of your coffee. BOP, ROP, EUR, FID. To the uninitiated, it might sound like a different language. To those in the industry, it is nothing but a condensed way of expressing concepts that are crucial.

The upstream segment comprises of exploration and production, which essentially means searching for hydrocarbons, drilling for them and lifting them out of the earth. The midstream sector transports the resource while the downstream sector refines and markets it. The upstream sector is characterized by high risks and heavy technical jargon. This glossary will take you through the terminology in the sequence in which a project occurs.

Exploration: Finding the Resource

Hydrocarbons are the organic compounds, mainly crude oil and natural gas, that the whole industry is built around.

Basin is a large depression in the earth’s crust where sediments, and often hydrocarbons, have built up over millions of years.

Source rock is where oil and gas form. Organic material is buried, heated and slowly converted. Reservoir rock is where the hydrocarbons end up, stored in tiny pore spaces. A cap rock (or seal) sits on top and stops them from escaping, and together these create a trap.

Porosity measures how much empty space a rock holds. Permeability measures how easily fluid moves through that space. A rock can be very porous and still be a poor reservoir if the pores are not connected.

Seismic survey uses sound waves to map what lies underground. You will see 2D, 3D and 4D (time-lapse) seismic. Geophysicists read the data to identify a prospect, a possible accumulation worth drilling, and a play, a group of prospects that share geological traits.

Drilling: Getting to the Target

A wildcat well is drilled in an area where there have been no discoveries. The appraisal well will be drilled next to determine the size of a discovery. When there is confirmation of the existence of a field and production is the target, then a development well will be drilled.

Spud marks the start of drilling. This activity is done by the drilling rig on land or jack-up/drillship offshore. Drilling fluid is circulated down through the drill pipe to cool the bit, lift cuttings and control formation pressure. Casing is the steel tubing that is cemented into the wellbore. The blowout preventer (BOP) is the critical safety stack on top of the well. If pressure surges unexpectedly, it can seal the well. Few pieces of equipment get as much attention from regulators and crews.

Directional drilling steers the well along a planned path, and horizontal drilling turns it sideways inside the reservoir to expose more rock to the wellbore. MWD (measurement while drilling) and LWD (logging while drilling) send real-time data from the bit to the surface so the driller can make decisions on the spot. ROP (rate of penetration) shows how fast the bit is cutting, and TD (total depth) is the final depth of the well.

Mud logging and wireline logging record what the formation is made of and whether it holds oil, gas or water. NPT (non-productive time) is any time lost to delays, and cutting it is one of the best ways to save money on a well.

Completion and Production

Once a well is drilled, completion prepares it to produce. This includes perforating the casing and installing tubing and a wellhead. At the surface, the valve assembly known as the Christmas tree controls flow.

Hydraulic fracturing (fracking) pumps fluid and proppant (usually sand) into tight formations to create pathways for oil and gas. It is the technology behind the shale boom and is common in unconventional plays.

When reservoir pressure drops, artificial lift helps. Options include the ESP (electric submersible pump), rod pumps and gas lift. Mature fields may also use enhanced oil recovery (EOR), such as water flooding or gas injection, to squeeze out more barrels.

At the surface, a separator splits the stream into oil, gas and water. Produced water has to be treated and disposed of responsibly. Flaring burns off gas that cannot be used, and it faces growing scrutiny. Flowback is the fluid that returns after a frac job.

Measuring What You Have

Bbl refers to one barrel of oil (159 liters). MMcf refers to one million cubic feet of natural gas. BOE (barrel of oil equivalent) allows oil and gas volumes to be combined in one number. API gravity determines the weight or lightness of a crude, while GOR (Gas-Oil Ratio) indicates the volume of gas in each barrel.

The reserve refers to recoverable volumes. The proved reserve (1P) is the most reliable, followed by probable reserve (2P), and the least reliable one is possible reserve (3P). EUR (Estimated Ultimate Recovery) is the total volume expected from a well throughout its lifespan.

Price is determined based on benchmarks, and there are two major ones (Brent and WTI). NGLs (Natural Gas Liquids) refer to by-products such as ethane and propane. LNG refers to liquefied natural gas.

Commercial and Contract Terms

The money side has its own vocabulary too. Working interest is a share of a project’s costs and revenues. Royalty is a share of production paid to the resource owner. A joint venture (JV) spreads risk among partners, and a production sharing contract (PSC) sets out how output is divided between a government and an operator. A farm-in lets a company buy into someone else’s licence by funding drilling.

CAPEX is money spent building assets, and OPEX is the cost of running them. NPV (net present value) tells you whether a project is worth doing. FID (final investment decision) is the point of no return when a company commits the capital.

At the end of a field’s life comes P&A (plugging and abandonment), where wells are sealed permanently. Throughout it all, HSE (health, safety and environment) sits above every operational decision.

Why This Vocabulary Matters

It’s quite tempting to think that a glossary is just something that you need to flip through. However, a common language ensures no misunderstandings. It happens that a geologist uses “3P” and a financial manager interprets it as “2P.” As for the difference in using “NPT” by a rig crew and an office team, it causes the loss of clarity in cost reporting.

This is particularly applicable to the industry that requires so much coordination between operators, drilling contractors, service companies, suppliers and regulators. Companies like GET Global Group, working in the energy industry, function under such conditions when communication between technical, commercial and field teams helps to keep projects on schedule. Knowing the terms doesn’t replace the experience but allows asking the right questions.

Tips for Learning the Language

• Learn terms in context. Follow one well from seismic to first oil and the vocabulary falls into place.
• Keep a personal list of abbreviations. Even veterans meet unfamiliar acronyms.
• Nobody in this industry is expected to know everything, and good colleagues explain willingly.
• Read company reports and regulatory filings, which use these terms constantly.

Final Thoughts

The upstream oil and gas industry is an industry that involves a lot of technical expertise, investments, and quick thinking, and that shows in the way it speaks. Being a newly graduated engineer, a vendor wanting to comprehend their clients, or an experienced engineer transferring between disciplines, having a good grasp on these terminologies is vital for you to become more efficient and confident.

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Frequently Asked Questions (FAQs)

1. What does “upstream” mean in oil and gas?Upstream refers to exploration and production: finding reserves, drilling wells and extracting crude oil and natural gas. It is also called the E&P sector.
2. What is the difference between upstream, midstream and downstream?Upstream finds and produces hydrocarbons. Midstream transports and stores them through pipelines, tankers and terminals. Downstream refines and sells the final products such as petrol, diesel and petrochemicals.
3. What is the difference between porosity and permeability?Porosity is the amount of empty space in a rock, while permeability is how well fluids can flow through that space. A good reservoir needs both.
4. What does BOE mean?BOE stands for barrel of oil equivalent. It converts natural gas volumes into the energy equivalent of oil barrels so companies can report total production as one number.
5. What is the difference between 1P, 2P and 3P reserves?1P (proved) reserves have the highest certainty of recovery. 2P adds probable reserves, and 3P adds possible reserves, which carry the most uncertainty.
6. What is a blowout preventer?A BOP is a large safety device fitted on top of a well. It can seal the well to control sudden pressure surges and prevent an uncontrolled release of fluids.
7. What does FID mean in oil and gas?FID, or final investment decision, is the stage where a company formally commits capital to develop a project after technical and commercial studies are complete.
8. How can someone new to the industry learn these terms faster?

   Follow a project through its full lifecycle, keep a running list of abbreviations, read industry reports and ask experienced colleagues to explain terms in plain language.