Secondary control is the proper use of blowout prevention equipment to control the well. The Drilling Supervisor is responsible for ensuring all relevant Drilling Contractor and Service personnel are aware of the standard Company Operational Practices, including well control methods and kick prevention.

The time spent with the pipe out of the hole shall be minimised. Routine BOP repairs and slipping and cutting of the drill-line shall be done with pipe at the casing shoe.


Pressure at the top of a Gas Influx in the Annulus using the "Driller's Method"

The pressure at the top of a gas bubble at any point in the annulus while circulating it out using the Driller’s method can be calculated as follows:

By calculating the expected annular…

Well Kill Using Combined Volumetric Stripping

If well kicks while tripping and the well is shut in, wait for instructions from the Drilling Superintendent. All equipment shall be arranged to implement the stripping operation. This means that:

  • it…

Well Kill Using The Driller's Method With The Bit On Bottom

In this method the well is killed in two circulations. In the first circulation the influx is circulated out using the original mud. In the second circulation, when weighted up mud is available, the…

Well Control - Circulating heavy mud (bit off bottom)

A non standard well control method is to attempt to bring the well under control by circulating heavy mud to overbalance the surface pressures. The theory behind this method is that the well can then…

Well Control Procedure - While on Bottom

Should an influx be detected while on bottom, the following procedure shall used:

1. RECOGNISE the kick and ALERT the crew.

2. STOP rotary table.

3. PULL BACK kelly until kelly cock is above rotary…

Well Control Procedure - While Out of Hole

To detect a kick while the string is out of hole it is essential that drilling fluid is circulated across the well and trip tank at all times.  Automatic alarms should be set to provide early…

Pressure at the top of a Gas Influx in the Annulus using the ‘Wait and Weight’ Method

The pressure at the top of a gas bubble at any point in the annulus while circulating it out using the “wait and weight” method can be calculated as follows:

By calculating the expected…

Kicks with Drill Collars in the BOP Stack

The detection of a kick when the drill collars are in the BOP stack is a time of concern for the safety of the crew and the drilling unit as the normal methods of secondary control using the…

Procedure and Calculation example for Change in Circulating Rate

Procedure and calculation example for Change in Circulating Rate while circulating an influx during a well control incident.

1. Calculate the average mud weight (Wav) in the string at the time pumping…

Well Control - Kick whilst tripping

If an overbalance existed prior to pulling out of hole, then the only reasons for the well to flow are:·swabbing;·failure to keep the hole full;·losses induced by surge pressures.

Early detection of…

Kicks with Casing in the BOP Stack

Well control precautions to be used when running casing.

  • Change the rams to the casing size (on surface stack) and test the BOP bonnets.
  • Prepare a circulating head.
  • Ensure a cross-over from casing to…

Well Control - Slim Hole Drilling

Slim Hole Drilling which, for the purpose of well control, means hole sizes of 4 3/4" and smaller, will impose certain restrictions on well killing techniques and will require well planning to take…

Well Control Procedure - While Tripping

To detect a kick while round tripping as early as possible, it shall be standard practice to use the trip tank at all times while tripping both into and out of the hole.

The Driller shall be…

Well Control - Volumetric Method

Well control by the volumetric method is a technique whereby bottom hole pressure is maintained slightly in excess of pore pressure whilst the gas influx is allowed to expand as it migrates to…

Well Control - Recognizing a kick and action to be taken

Recognising a kick and need for immediate action.A kick occurs when the hydrostatic pressure of the mud column in the well is less than the pore pressure of a producing formation.Drilling breaks and…

Well Control - Stripping Method

This article describes the keys elements for the stripping method for well control

Complications during well control operations

Complications during well control operations Stopping the control operation, Plugged chokes, Change in circulating kill rate, Plugged bit nozzles, Kick caused by loss of circulation below production…

Problems Encountered During Well Control

Problems Encountered During Well Control

Conventional well killing procedures are based upon the basis that all of the well control equipment operates as designed and the wellbore is able to withstand the imposed pressures.

Mechanical…

Non-conventional well control methods

Non-conventional well control methods

When the standard well control method (drillers' or weight and wait) are not suitable, alternative methods can be considered: Stripping, bullheading, volumetric, off-botton, no circulation, etc

1.…

Bullheading

If normal well killing techniques are not possible or will result in critical well control conditions bullheading may be considered whereby mud/influx in displaced/squeezed back into the weakest open…