Triggering of the Lusi mud eruption: Earthquake versus drilling initiation

Research Article| August 01, 2008 Triggering of the Lusi mud eruption: Earthquake versus drilling initiation Mark Tingay; Mark Tingay 1School of Earth and Environmental Sciences, University of Adelaide, South Australia 5005, Australia *Present address: Department of Applied Geology, Curtin University of Technology, Western Australia 6102, Australia; m.tingay@curtin.edu.au Search for other works by this author on: GSW Google Scholar Oliver Heidbach; Oliver Heidbach 2Geophysics Institute, Universitat Karlsruhe, Hertzstrasse 16, Karlsruhe 76187, Germany Search for other works by this author on: GSW Google Scholar Richard Davies; Richard Davies 3Department of Earth Sciences, University of Durham, Science Labs, Durham DH1 3LE, UK Search for other works by this author on: GSW Google Scholar Richard Swarbrick Richard Swarbrick 4GeoPressure Technology, Stockton Road, Durham DH13UZ, UK Search for other works by this author on: GSW Google Scholar Author and Article Information Mark Tingay *Present address: Department of Applied Geology, Curtin University of Technology, Western Australia 6102, Australia; m.tingay@curtin.edu.au 1School of Earth and Environmental Sciences, University of Adelaide, South Australia 5005, Australia Oliver Heidbach 2Geophysics Institute, Universitat Karlsruhe, Hertzstrasse 16, Karlsruhe 76187, Germany Richard Davies 3Department of Earth Sciences, University of Durham, Science Labs, Durham DH1 3LE, UK Richard Swarbrick 4GeoPressure Technology, Stockton Road, Durham DH13UZ, UK Publisher: Geological Society of America Received: 20 Dec 2007 Revision Received: 01 May 2008 Accepted: 04 May 2008 First Online: 02 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 © 2008 Geological Society of America Geology (2008) 36 (8): 639–642. https://doi.org/10.1130/G24697A.1 Article history Received: 20 Dec 2007 Revision Received: 01 May 2008 Accepted: 04 May 2008 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Mark Tingay, Oliver Heidbach, Richard Davies, Richard Swarbrick; Triggering of the Lusi mud eruption: Earthquake versus drilling initiation. Geology 2008;; 36 (8): 639–642. doi: https://doi.org/10.1130/G24697A.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract The Lusi mud volcano in East Java has erupted unabated for almost 2 yr, flooding an area of 7 km2 and displacing more than 25,000 people. Despite its disastrous impact, the mechanism for triggering the Lusi eruption remains highly controversial; two distinct mechanisms have been proposed. One hypothesis suggests that the eruption was triggered by the Mw 6.3 earth-quake that struck Yogyakarta (250 km from Lusi) two days before the eruption. However, an examination of static and dynamic stress changes and stress transfer mechanisms indicates that the Yogyakarta earthquake was at least an order of magnitude too small to reactivate faults and open fluid flow pathways under Lusi. An alternate theory suggests that Lusi was triggered by a blowout following drilling problems in the nearby Banjar Panji-1 well. Blowouts result from an inability to control pore fluid intakes into the borehole and typically occur when the drilling window (fracture pressure minus pore pressure) is approximately zero and when there is insufficient protective casing of the well bore. Pore and fracture pressure data from Banjar Panji-1 indicate that the well had a narrow drilling window of only 0–2.3 MPa. Furthermore, two planned casing points were skipped during drilling, resulting in 1742 m of unprotected borehole. The combination of hazardously narrow drilling window and long uncased borehole would have made drilling problems in Banjar Panji-1 difficult to control, placing the well at high risk of blowing out. Furthermore, well-bore pressures following drilling problems in Banjar Panji-1 reached magnitudes in excess of the fracture pressure and thus were sufficient to create fluid flow pathways in the subsurface. Therefore, we suggest that no viable method is known by which the Yogyakarta earthquake could have triggered the mudflow and that a blowout in the Banjar Panji-1 well was the most likely mechanism for triggering the Lusi eruption. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.