Astronomy and Astrophysics – Astrophysics
Scientific paper
Sep 2011
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011esrv..108...50z&link_type=abstract
Earth Science Reviews, Volume 108, Issue 1-2, p. 50-63.
Astronomy and Astrophysics
Astrophysics
Abnormal Pressure, Pore Pressure Prediction, Fracture Gradient, Compaction Disequilibrium, Normal Compaction Trendline, Porosity And Overpressure, Effective Stress, Velocity And Transit Time, Resistivity, Subsalt Formations
Scientific paper
Pore pressures in most deep sedimentary formations are not hydrostatic; instead they are overpressured and elevated even to more than double of the hydrostatic pressure. If the abnormal pressures are not accurately predicted prior to drilling, catastrophic incidents, such as well blowouts and mud volcanoes, may take place. Pore pressure calculation in a hydraulically-connected formation is introduced. Fracture gradient prediction methods are reviewed, and the minimum and maximum fracture pressures are proposed. The commonly used empirical methods for abnormal pore pressure prediction from well logs are then reviewed in this paper. Eaton's resistivity and sonic methods are then adapted using depth-dependent normal compaction equations for pore pressure prediction in subsurface formations. The adapted methods provide a much easier way to handle normal compaction trendlines. In addition to the empirical methods, the theoretical pore pressure modeling is the fundamental to understand the mechanism of the abnormal pressure generation. A theoretical pore pressure-porosity model is proposed based on the primary overpressure generation mechanism — compaction disequilibrium and effective stress-porosity-compaction theory. Accordingly, pore pressure predictions from compressional velocity and sonic transit time are obtained using the new theoretical model. Case studies in deepwater oil wells illustrate how to improve pore pressure prediction in sedimentary formations.
No associations
LandOfFree
Pore pressure prediction from well logs: Methods, modifications, and new approaches does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Pore pressure prediction from well logs: Methods, modifications, and new approaches, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Pore pressure prediction from well logs: Methods, modifications, and new approaches will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-832516