Types of Oil and Gas Platforms: What You Need to Know

The oil and gas sector stretches past drilling a hole and discovering black gold. On a national scale, this is still an economic catastrophe but the OPEC production cut fits into a much broader and far more complex international jigsaw that was never going to join up easily or quickly. It’s already in place and will only grow larger because oil isn’t capitalism’s wheelchair yet alone life support machine it’s global capital as we know it, grafted by time and vast human effort onto a wildly inefficient substance extracted from deep underground; refineries are curtains drawn against inevitable loss.

The Sectors: Prospective to a Producing Industry

It starts with the Quest for Discovery, where geologists and engineers start looking for new reserves. If data is positive, the project goes first to upstream where it refers to extraction and basic processing of crude oil and natural gas.

After being produced, hydrocarbons are transported by a midstream network of pipelines, terminals, and tankers to refineries where crude is turned into gasoline, diesel, jet fuel; or petrochemical feedstocks. Then petrochemical plants convert those feedstocks to plastics, fertilizer, solvents and an array of other products that are used in everyday life.

Onshore Production: The Workhorse of the Industry

Onshore fields, by contrast, are the backbone of the industry, dispensing its oil at the low prices they can get away with charging to extract such small per-well output: from a few dozen to thousands of barrels every day. Wellheads cover the landscape in mature oil provinces, connected by sprawling gathering networks hundreds of kilometers long running to central processing plants.

Small scale could be as oil stored in a tank to bite it up by truck or rail. In the largest fields, wellstreams go to gas–oil separation plants (GOSPs) that can handle over 1 × 10^6 bbl/d), with shipping via pipeline or tanker.

Summary Unconventional resources have been catalysts to the transformation of onshore production over recent years:

• Before the bitumen can be extracted from sand it needs heating, or additional diluents, since heavy crude and tar sands need steam assisted extraction to get to the bitumen.
• Horizontal drilling and hydraulic fracturing have unlocked vast amounts of shale oil and gas that has utterly transformed the supply landscape in the United States as well as other parts of the world.

There can be as much as twice the natural gasses compared to reservoirs of conventional type in these layers.

Offshore Production: Extreme Engineering

Offshore fields require an entirely different [array of facili¬ties designed each] to water depth, weather, and reservoir location.

Multiple platforms wellhead, processing, power, and accommodation linked by bridges (shallow-water complexes)

Further out, operators rely on gravity base structures (GBSs), titanic concrete platforms sunk to the seabed that can include storage tanks. Compliant tower technology lets the platform go to 3000 feet of water, and their supple steel brace works like suspension on a car for an additional 3,000 feet of vertical seaward reach.

And even beyond that, it is floating production systems:

• Floating Production, Storage, and Offloading units (FPSOs):

They treat oil in the vessel’s hull before transporting it to shuttle tankers. They can be used primarily for on-remote fields, and could accommodate flows from 10,000 to over 200,000 barrels per day.

• Tension Leg Platforms (also known as TLPs)

Which is placed by vertical tendons and are designed to be fixed even in the deep waters of as much as 2,000 meters.

• Semisubmersibles

They are designed with partially submerged pontoons for buoyancy and stability along with flexible risers to connect the platform to the seafloor and attached to subsea wells.

• SPAR platforms

a deepwater oil terminal that is typically moored to the seafloor for stability; works at depths up to 3,000 meters.

Subsea manufacturing techniques

completely eliminate the topside platform. Wells at the seabed are drilled to extract oil and gas that are then led through pipelines into remote platforms or directly to shore. More recent designs are going for full-scale, completely independent seabed factories equipped with onboard processing systems.

How Production Works

This process of onshore or offshore is the same for everyone:

1. The reservoir’s flow is controlled via well heads.
   
2. Manifolds direct several wellstreams into processing equipment.
   
3. Gathering systems transport fluids to central plants.
   
4. Oil, gas and condensates (oil-rich hydrocarbons) are separated at processing facilities by removing impurities such as water, CO₂ and sand.
   
5. Domestic systems keep everything running: power, water, compressed air and safety systems.

From Reservoir to Market

This scale can range from a 100-barrel-per-day onshore well in a remote field, all the way up to multi-billion-dollar deepwater developments miles offshore in thousands of feet of water. Though the scale and technology are far different, the goal is still to supply hydrocarbons safely, efficiently, and reliably to markets throughout the world. Whether it be a variety of donkey pumps on a Texas plain, an FPSO floating off West Africa, or a subsea manifold in the Gulf of Mexico, that infrastructure is all part of one interconnected global apparatus large enough to keep economies moving. The facilities may look like different donkey pumps on a Texas plain, a floating FPSO off West Africa, or a subsea manifold in the Gulf of Mexico but they are all part of a single global system that keeps economies moving.

Oil and gas platforms play a vital role in the upstream stage of the industry, where exploration and production take place. These offshore structures are designed to drill, extract, and process hydrocarbons before they enter the midstream and downstream phases of the value chain. For insights into how platforms connect to the broader oil and gas journey, refer to our guide on “Upstream, Midstream, and Downstream in the Oil & Gas Industry.”