Early Kick Detection Through Liquid Level Monitoring in the Wellbore

Abstract Through the years many tools have been developed to detect kicks in their early stages, when they can be handled more easily and safely. However, most of these tools are dependent upon the well being full of fluid with the liquid at the surface. When drilling wells where there are severe lost circulation problems (e.g., no returns to the surface) many of the major kick detection tools do not function properly since the liquid level may be hundreds or thousands of feet below the surface. During tripping operations, the major kick indicator is measurement of the volume of drilling fluid required to "fill" the hole to replace the volume of steel removed. If the annulus cannot be filled, again due severe losses to the open formation, measurement of the fluid pumped into the annulus does not give meaningful information as to formation fluid influx until the influx is great enough to begin to unload the annulus. This paper proposes the use of an acoustic device installed on the casing valve to continuously monitor the liquid level in the annulus of wells experiencing complete loss of returns. A rise in liquid level can be interpreted as an early indication of a kick during drilling or tripping operations. The liquid level can also be used to determine the correct volume of fluid to pump into the well while tripping out of the hole. This paper presents the results of tests run using common acoustic tools to monitor the liquid level in the wellbore of an Austin Chalk re-entry. Results of these tests show that the liquid level can be accurately monitored during complete lost returns so that kicks can be detected early during drilling or tripping operations. P. 889