From Wellhead to Export: The Whole Picture
The main process blocks of a production facility, how they connect, and why a problem in one block shows up in another.
11 min
Activities: 0 of 2
One stream in, three products out
A surface production facility takes the mixed stream from the wells and turns it into products that can be sold or safely disposed of. In most facilities there are three main products: stabilised crude oil, sales gas (or gas for injection or fuel), and treated produced water. Solids such as sand are a fourth stream that must also be handled.
This course covers the whole route between the wellhead and the export point. It is written for operators, technicians, engineers and supervisors who already know the basic equipment names and now need to apply that knowledge: choose between options, diagnose problems and judge trade-offs.
The route of the well stream
- 1
Step 1
Wellheads, chokes and manifolds
The choke reduces pressure and controls each well. The manifold collects wells into production and test headers. - 2
Step 2
Separation
Separators split gas, oil and water, usually in several pressure stages. - 3
Step 3
Oil treating
Heat, chemicals, time and electrostatic grids remove remaining water and salt. Stabilisation removes light ends. - 4
Step 4
Gas handling
Compression, dehydration, acid gas removal and dewpoint control prepare the gas. - 5
Step 5
Water treatment
Oil and solids are removed so the water can be injected or discharged. - 6
Step 6
Metering and export
Custody transfer meters measure what is sold. Pipelines, tankers or trucks take it away.
Why the blocks cannot be treated separately
Every block depends on the one before it. If the separator sends too much water with the oil, the treater is overloaded. If the separator sends liquid with the gas, the compressor and the glycol unit suffer. If oil goes with the water, the water treatment train cannot meet its limit.
Utilities connect everything as well. Instrument air, power, fuel gas, heating medium and the flare system serve all the process blocks. A failure in one utility can stop the whole facility.
Three ideas used through the whole course
Match the block to its main job
Pair each process block with what it does.
- Separation
- Oil treating
- Gas dehydration
- Water treatment
- Custody transfer metering
A facility’s oil rate falls when the gas compressor trips, although the oil equipment works normally. What is the best explanation?