A kick is generally recognised by an instantaneous increase in the rate of mud returns and/or an associated gain in mud volume in the active mud tanks. A flowline show (gas cut or fluid contaminated mud) does not necessarily mean that the well is kicking. Flowline shows can be: drilled shows; swabbed shows; high pressure … Well Control – Flowline Shows

There are four principal causes of loss of primary control: swabbing, insuficient fluid density, losses, failure to fill the hole correctly. 1 Swabbing Swabbing can also be caused by pulling full gauge tools which restrict the passage of fluid in the annulus. This creates a piston effect and the volume below the tool would be … Well Control – Loss of Primary Control