The alertness in determining early possible kick indicators in well control is of the utmost importance to prevent a well control incident. Careful observance and positive reaction to these signs will keep the well under control and prevent the occurrence of a well control situation.
The various signs that have been recorded as early warning indicators are not consistent in all situations. The signs however may have to be used collectively as one indicator may not accurately provide the warning of getting into an underbalanced situation. Even though the series of signs may change between wells, early warning indications can be found from the following list.
- Increase in drilling rate of penetration.
- Increase torque and drag.
- Decrease in shale density.
- Mud property changes.
- Increase in cutting size and shape.
- Increase in trip, connection and/or background gas.
- Increase in the temperature of the return drilling mud.
- Decrease in D-exponent.
Many people tend to confuse between possible and positive well control indicators therefore we would like to differentiate between these two well control indicators. These two concepts are vital for well control because one indicate the possibility of the kick but another one shows definite signs that the well is taking back to you. In this article, we summarize all information regarding the possible and positive kick indicators so you can use for your work.
Possible Well Control (kick) Indications
Possible well control (kick) indicators mean that there is possibility to get influx into wellbore. It MAY or MAY NOT be a kick.The indications can be either kick or just formation react while drilling. You need to remember that just only a single possible indicator cannot may not good enough to identify underbalanced condition in wellbore and the possible kick indicators must be used collectively. Therefore, drilling team on the rig needs to closely monitor the well and prepare appropriate action plans.
The possible well control (kick) indications are as follows;
Change in drilling breaks (ROP change) – If the differential between formation pressure and hydrostatic pressure created by drilling mud decreases, there is possibility to increase rate of penetration because the hold down effect is decreased.