Shut-in
- Also known as
- shut in, shut-in well
To shut in a well is to close it so that it stops producing or injecting, typically by closing valves at the wellhead. Wells are shut in for maintenance, testing, low prices, regulatory reasons or weather, and restarting them can bring problems such as wax, emulsions and water blocks.
What does shut-in mean?
A well is shut in when its flow is stopped, usually by closing wellhead valves, while it remains capable of producing. A shut-in well differs from a plugged and abandoned well, which has been permanently sealed. The pressure measured at the wellhead of a closed well is the shut-in pressure.
Why wells are shut in
- Workovers and maintenance.
- Pressure buildup tests, which measure how pressure recovers to evaluate the reservoir.
- Low commodity prices, when producing does not cover operating costs.
- Pipeline or processing constraints.
- Nearby operations, such as hydraulic fracturing on neighboring wells.
- Treatments, such as a scale squeeze, that require a soak period.
- Weather and regulatory requirements.
Problems during shut-in and restart
- Paraffin deposition and gelled oil as fluids cool in the wellbore and lines, especially with oils that have a high pour point.
- Fluid segregation, with water settling and potentially entering the near-wellbore area.
- Water blocks and other formation damage that can reduce production after restart.
- Emulsions and deposits that form when production resumes.
- Corrosion in stagnant fluids.
- Mechanical issues with pumps and equipment left idle.
Some wells do not return to their previous production rates after an extended shut-in, which is why operators may treat wells before shutting them in or before restart.
Frequently asked questions
No. A shut-in well is temporarily closed and can be returned to production. An abandoned well has been permanently plugged.
The pressure at the wellhead or bottom of the well after flow has stopped, which indicates reservoir pressure and is used in well testing.
Sources
- shut in; shut-in pressure, SLB Energy Glossary