Schlumberger Technology Corporation

Iead Rezek

Ashley Bernard Johnson

Benjamin Peter Jeffryes

Walter David Aldred

Oney Erge

Jonathan Dunlop

Richard Dearden

Ines De Mata Cecilio

A method for detecting an influx and/or loss of circulation in a wellbore, comprising measuring a condition in the wellbore using a downhole sensor; determining that a positive displacement pump is shut off or turned on; predicting pit volume and/or gas concentration at a plurality of time points after the positive displacement pump is shut off or turned on using the measured condition in the wellbore prior to the positive displacement pump is shut off or turned on, wherein the measured condition correlates with the pit volume and/or gas concentration; measuring pit volume and/or gas concentration at the plurality of time points; comparing the predicted and the measured pit volumes and/or gas concentrations at the plurality of time points; and producing a warning signal if the difference between the predicted and the measured pit volumes and/or gas concentrations is greater than a pre determined value.

Detection of influx and loss of circulation

Growing community of inventors

Cambridge, United Kingdom

Iead Rezek