Abstract
Drillstring vibration information can be used to define the geology of the well. Some geological phenomena in horizontal wells can be revealed from drill string vibration data. Examples include faults, exiting and entering the reservoir, different lithology and rock strength. In addition, uncontrolled vibrations can also limit the optimization of drilling performance, for instance increasing the possibility of stuck pipe, affecting wellbore stability, reducing drilling tool life, and causing tool failure. This paper aims to gather vibration data from drilled horizontal wells and classify them based on the geological and lithological environment in which they were observed. Three major kinds of vibrations are resulted from horizontal drilling; axial vibration, lateral vibration, and torsional vibration. Vibration data were collected and grouped together to correlate vibration behavior to the geology of the horizontal well. These vibrations data were compared in different geological situations; for example in clastic and carbonate environments, drilling through changing lithology, exiting the reservoir, and passing through a series of faults. The correlation can then be utilized in geo-steering application.
The objective of this paper is to enable engineers to characterize the vibration data according to potential risk factors that may be encountered during real-time geo-steering, and to take actions that optimize the drilling operation. Observations have revealed a strong correlation between vibration behavior and geological phenomena in drilling operations. These observations enable confirmation of various geological features from geo-steering modelling. Furthermore, adjusting drilling parameters and implementing good drilling practice would minimizes the tool exposure to excessive vibrations in order to avoid tool failure, and optimizes drilling operation. An understanding of the vibration data can also be used to help geo-steer and support the justification for any adjustment in the lateral section. This will not be a proactive adjustment but more of a reactive adjustment. An additional objective is to find the best tool configuration in certain horizontal well environments, thereby improving the drilling optimization and enabling optimum procedures by capturing the right downhole dynamics when encountering excessive vibrations. These findings will help drilling to control the well and contribute to the wellbore stability. This will be the first paper to characterize vibration behavior in relation to the geological phenomena and applying it in horizontal wells.