THE INFLUENCE OF SALT DOMES IN DRILLING WELL ACTIVITIES

The present work discusses the challenges associated with the drilling activities in oil wells through formations affected by the presence of salt domes. These geological structures can induce large stresses in the underlying and adjacent formations, requiring the development of specific planning for drilling and maintenance of such oil wells. During drilling, due to the presence of salt, numerous reports of problems such as stuck pipe, salt dissolution, forming mechanical stops and caves arise. More specific difficulties can occur in formations around a salt dome, related to the changes in the stress field, which include problems of well instability and abnormality of pressure zones. After casing, issues involving collapsing case-structures can take place. To prevent and mitigate risks associated to this activity, it is crucial to understand the physical phenomena behind it. With such finality, the present work studies problems related to such physical mechanisms, for instance, hydrodynamic instability, more specifically, the Rayleigh-Taylor (RT) instability. This study led to the development of an analytical model to predict salt dome formation. It discusses the ways in which it can interfere positively in parameters related to the drilling activity as, for example, the tension field in the formation around the salt dome