From the previous topic, estimate Height of Influx, you can use influx height to estimate type of influx.

The following equation is used for estimating type of influx:

Note: You can prove the equation by using the U-tube concept.

Where;

Influx weight in ppg

Current mud weight in ppg

SICP stands for Shut In Casing Pressure in psi.

SIDPP stands for Shut In Drill Pipe Pressure in psi.

Influx height in ft

Once you know weight of influx, you can compare with these figures below to determine type of influx.

1 – 3 ppg most likely gas influx.

3 – 7 ppg most likely oil kick or combination between gas and oil kick

7 – 9 ppg most likely water influx

**With these given information, please determine type of influx.**

Shut in casing pressure = 1050 psi

Shut in drill pipe pressure = 750 psi

Height of influx = 450 ft

Current Mud Weight = 14.0 ppg

Influx weight = 1.2 ppg

According to the criteria above, the influx is most likely gas kick.

**Reference****:**

Formulas and Calculations for Drilling, Production and Workover, Second Edition by Norton J. Lapeyrouse (Author)

I have equip myself to an extent in my career in oil and gas industry. Also,I hope to get more informations on formulars and equations to enable me trobleshoot accurately.

Nice equation, simple equation is able to predict and estimate the influx type downhole.