1. Introduction
During drilling operations, the detection of a kick demands immediate shut-in of the well to prevent uncontrolled migration of formation fluids. The effectiveness of this response depends on how quickly the circulation is halted and the BOP (Blowout Preventer) is closed.
2. What is Shut-In Time?
It is the interval between kick detection and the actual closure of the well. This time window directly influences the amount of formation influx and, therefore, the complexity of the subsequent control procedures.
3. Practical Example: Pressure Build-Up After Shut-In
The table below shows how pressures in the drill pipe (SIDPP) and annulus (SICP) rise over time after shut-in:
| Time After Shut-In (min) |
Drill Pipe Pressure (SIDPP) [psi] |
Choke Line Pressure (SICP) [psi] |
| 0.0 |
0 |
0 |
| 2.5 |
190 |
210 |
| 5.0 |
270 |
300 |
| 7.5 |
310 |
350 |
| 10.0 |
330 |
370 |
| 12.5 |
340 |
380 |
| 15.0 |
350 |
390 |
| 17.5 |
360 |
400 |
Estimated stabilized values:
These values are essential for calculating the Initial Circulating Pressure (ICP) and estimating the influx gradient.
4. Consequences of Delayed Shut-In
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Higher influx volume in the well
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Greater influx height and migration energy
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Increased surface pressure, complicating pressure control
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Higher risk of exceeding formation fracture pressure
5. Operational Recommendations
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Continuous crew training for fast reaction
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Real-time monitoring of volume gains and pressure trends
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Strict standard procedures for shut-in execution
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Use of reliable and calibrated pressure gauges
6. Conclusion
Shut-in time is not just an operational metric—it determines the complexity and risk of kick control. The shorter the time, the better the control. Rapid shut-in is key to minimizing formation influx and ensuring the safety and integrity of the well.