RETRACTED ARTICLE: Predictability and controlling factors of overpressure in the North Alpine Foreland Basin, SE Germany: an interdisciplinary post-drill analysis of the Geretsried GEN-1 deep geothermal well

Abstract

For the first time, drilling-and velocity-based well analysis and 3D basin modeling were combined to test the predictability and controlling factors of overpressure in the North Alpine Foreland Basin in SE Germany. More specifically, the techniques were tested in the sub-regional context of the deep geothermal well Geretsried GEN-1 (TVD = 4852 m), located in the south of Munich. A 3D basin model based on a total of 20 wells was calibrated to the pressure distribution of four petroleum wells and tested against the Geretsried GEN-1 well. The results demonstrate that overpressure in the North Alpine Foreland Basin SE Germany can be predicted from a simple 3D basin model calibrated to a minimum number of wells. Thereby, disequilibrium compaction likely acts as the main overpressure mechanism in the study area, underpinned by significantly higher sedimentation rates at overpressured locations. 3D basin modeling also confirms the role of Upper Cretaceous shales, which, if present, serve as an important pressure barrier between the under-to normally pressured Jurassic and overpressured Cenozoic basin fill. In addition, overpressure magnitudes of the Chattian might be higher than previously expected. The results of this study have great impact on future drilling campaigns in the North Alpine Foreland Basin in SE Germany. Minimized non-productive time and drilling cost, improved well planning and increased safety are amongst the most important benefits of accurate pore pressure and overpressure prediction. The newly derived insights on the mechanisms of overpressure will greatly influence future geomechanical and tectonic studies, since pore pressure drives rock strength and principle stress magnitudes. Finally, the study is a great example for the importance of an interdisciplinary approach and the incorporation of geological conditions, when investigating drilling-related problems. Open Access© The Author(s) 2019. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creat iveco mmons .org/licen ses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

Reconstructing post-Jurassic overburden in central Europe: new insights from mudstone compaction and thermal history analyses of the Franconian Alb, SE Germany

“…with the vertical effective stress gradient VES grad typically varying between 10 and 16 MPa km −1 in hydrostatically pressured sedimentary basins, derived from a vertical stress gradient of 20-26 MPa km −1 and a hydrostatic pore pressure of 10 MPa km −1 (Bjørlykke, 2015). For the NAFB, Drews et al (2018Drews et al ( , 2020 determined a vertical effective stress gradient of 13 MPa km −1 , which will also be used for depth calculations in this study.…”

A multi-proxy approach to detect the pore pressure and the origin of overpressure in sedimentary basins: An example from the Gulf of Suez rift basin

“…Abnormal pore pressure is one of the main challenges for drilling engineers and exploration geologists, and it can be subclassified into overpressure and sub-normal pressure (Figure 1) (e.g., Bourgoyne et al, 1986;Mouchet and Mitchele, 1989;Neuzil, 1995;Yassir and Bell, 1996;Osborne and Swarbrick, 1997;Sayers et al, 2002;Ramdhan and Goulty, 2010;Ramdhan and Goulty, 2011;Zhang, 2011;Radwan et al, 2019a;Radwan et al, 2020a;Radwan, 2021b). Overpressure generation mechanisms (Figure 2) have been studied in many sedimentary basins, and they are linked with disequilibrium compaction (e.g., Martinsen, 1994;Hart et al, 1995;Klaus, 1999;Vejbaek, 2008;Kumar and Rao, 2012;Marín-Moreno et al, 2013;Wang et al, 2016;Drews et al, 2019;Zhang et al, 2019;Li et al, 2021), clay diagenesis (e.g., Jeans, 1994;Lahann et al, 2001;Katahara, 2006;Lahann and Swarbrick, 2011), tectonic activities (e.g., Hao et al, 2004;Luo et al, 2007), hydrocarbon generation (Spencer, 1987;Osborne and Swarbrick, 1997;Hansom and Lee, 2005;Chi et al, 2010), and thermal effects (e.g., Mello and Karner, 1996;He et al, 2002).…”