Previous Talks

Impact of Geomechanics on BHA design and performance monitoring while drilling salt

Cem Ozan, Statoil


Drilling salt sections in deep water wells has been a challenging task due to salt creep and subsequent wellbore closures.  Potential problems have been mitigated by utilizing a reamer since drilling a larger size hole in salt sections would allow enough time for the BHA to drill and pull out of hole before salt can creep in and cause drilling problems.

In this example, the open hole covered both the salt and the underlying potential reservoir intervals.  This section would normally be drilled with a reamer and could cause potential problems in subsequent wireline operations. In addition, a longer BHA could increase the cost and also the likelihood of tripping problems.

In order to assess the creep potential of the salt as well as the BHA performance during drilling and POOH, we have considered the structural geology of the region and compiled geomechanical observations, i.e., salt flow directions and velocities, and drilling observations.  Based on this information, we constructed models that allowed us to assess the impact of salt creep on operations.  As a result, we have concluded that particularly at this specific location in the GoM, wellbore closure due to salt creep does not affect drilling operations. This allowed us to exclude the reamer in the salt section.  This presentation explains the details of this technical work and its operational outcomes.

Speaker Biography

Cem Ozan joined Statoil in 2013 and has been working in Statoil’s Houston office in the Exploration group as a senior pore pressure and geomechanics specialist.  Prior to his current assignment, he worked for GeoMechanics International (later Baker Hughes – Reservoir Development Services) for 6 years as Geomechanics Specialist and Senior Technology Developer.  He received his Ph.D. in Geosystems Engineering in 2008 from Georgia Institute of Technology, and holds MSc. degrees in Geosystems and Geotechnical Engineering from Georgia Tech, Atlanta and METU, Ankara, respectively.