Previous Talks

Wednesday, October 12th, 2011

Use of wellbore images while drilling for real-time wellbore stability analysis and mitigation

Steve Edwards, BP


Wellbore instability while drilling continues to be a significant challenge for the oil and gas industry. Instability is the root cause of non-productive time associated with tight hole, excessive hole cleaning/back reaming and stuck pipe. Hole instability can also compromise processes such as running casing, cementing and installation of completions equipment. Instability is therefore not only an additional drilling cost, but can also potentially compromise an entire field development.

Great progress has been made in recent years in modeling wellbore instability. When all the rock properties and in-situ conditions (pore pressure and stress) are known, the industry is very capable of modeling the wellbore and determining the required mud weight. However, in the real world, particularly at early stage of a field development, rock properties and in-situ conditions are often not known very accurately. In such cases, instability while drilling and the associated problems are not uncommon.

Real-time monitoring while drilling is not a new concept. It is now common practice to perform at least some type of real-time pore pressure analysis in over pressured areas. Recent developments in logging while drilling (LWD) technology and telemetry offer an opportunity to extend this real-time monitoring to wellbore stability through the use of real-time wellbore caliper and image data.

This presentation will show the evolution of real-time imaging in BP and how it has been used for real-time wellbore stability management. Examples will be presented to illustrate early attempts using low bandwidth mud pulse and 4-sector images through to the “state of the art” using high bandwidth telemetry (wired drill pipe) and high resolution (16 sector density and 128 sector resistivity) images. Examples will be shown where hole sections have been saved by pro-actively using real-time imaging to fine-tune the mud weight in challenging tight margin/high angle environments.

Speaker Biography

Steve Edwards works as a Geomechanics Specialist in BP’s Global Wells Engineering Team in Houston. He provides geomechanics support to drilling, completions, reservoir and base management operations. Steve was also recently leader of the “Wired Drillpipe Applications Project” within BP’s drilling technology flagship. Steve graduated from the University of Oxford in 1991 with a bachelor’s degree in Geology and Geophysics and from the University of London in 1997 with a Ph.D. in Geomechanics. After working as a Geomechanics Engineer for Schlumberger from 1997 to 2001, Steve joined BP.