The estimation of pore pressure from LWD or wireline logs has traditionally been an art.  The key to making accurate pressure predictions has lain with the selection of the normal compaction trend.  The selection of a normal compaction trend has varied by user in the past.  This practice has lead to inconsistencies in predictions as different users define their normal compaction trends to fit their individual preconceptions of pressure in the well being analyzed. 

Recent understanding has lead to the ability to consistently predict the normal compaction trend that leads to more consisten results from well to well, area to area, and user to user.  The use of this new understanding is leading to "best practices" that are improving the quality and consistency of predictions that, in turn, lead to improved drilling performance and basin pressure understanding.