Choke Management
A choke is a restriction device installed at the wellhead (surface choke) or downhole that controls the flow rate from a well. Choke management is the practice of adjusting choke size to optimise production rate, manage reservoir drawdown, prevent sand production, and protect downstream facilities.
Why Choke Management Matters
Rate Control
Opening the choke increases the production rate; closing it reduces the rate. The choke is the primary tool for controlling how fast a well produces.
Example: A new well is brought online with a 24/64" choke. Over the first week, the choke is gradually opened to 48/64" to avoid damaging the formation with excessive drawdown.
Sand Prevention
Excessive drawdown can cause formation sand to flow into the wellbore, damaging equipment. Choking back the well reduces drawdown and keeps flow velocity below the critical sand production threshold.
Water & Gas Coning Control
Producing too aggressively can cause water or gas to cone into the wellbore. Reducing the choke lowers the drawdown, delaying the onset of coning and extending the well's productive life.
Example: Well-C03 water cut jumped from 30% to 55% after the choke was opened from 32/64" to 56/64". Choking back to 40/64" reduced water cut to 38% while maintaining 85% of the peak oil rate.
Facility Protection
The choke also protects downstream equipment (separators, pipelines) from pressure surges. The wellhead pressure downstream of the choke must not exceed the separator design pressure.
Fixed vs Adjustable Chokes
Fixed (Positive) Choke
A bean with a fixed orifice size. Changing the size requires shutting the well in and physically replacing the bean. Common in simple onshore operations.
Adjustable Choke
A valve that can be opened/closed to vary the orifice size without shutting in the well. Essential for digital oilfields where remote choke adjustments are made from the control room.