Page 169 - Practical Well Planning and Drilling Manual

Section 2 revised 11/00/bc 1/17/01 12:04 PM Page 145

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2.2

Well Control

The main objectives of the BOP program are to ensure that if pri-
mary well control (hydrostatic) is lost, personnel and equipment are
not endangered and the well can be brought back under primary con-
trol. In the case of drilling with a diverter, the well cannot be closed in
and the diverter system is for safe rig evacuation during an extended
flow rather than for bringing the well back under control. If a shallow
gas kick occurs on a nonfloating rig, nonessential personnel should be
evacuated until the situation is brought under control and preparations
are made to evacuate the remainder if necessary.
This section will consider well control from a drilling programming
viewpoint. Practical well control aspects are discussed in Section 3,
“Practical Wellsite Operations and Reporting.”

2.2.1. Shallow Gas

The most complex and dangerous well control situation is a shal-
low gas blowout, occurring before BOPs can be installed. A shallow gas
kick can occur with little warning, it may involve H S and presents a
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