eprintid: 1683 rev_number: 13 eprint_status: archive userid: 2 dir: disk0/00/00/16/83 datestamp: 2016-05-30 13:21:31 lastmod: 2017-02-08 12:21:34 status_changed: 2016-05-30 13:21:31 type: article metadata_visibility: show creators_name: Garcia, Julio creators_name: Hartline, Craig creators_name: Walters, Mark creators_name: Wright, Melinda creators_name: Rutqvist, Jonny creators_name: Dobson, Patrick F. creators_name: Jeanne, Pierre creators_id: Julio.garcia@calpine.com creators_id: creators_id: creators_id: creators_id: creators_id: creators_id: corp_creators: Calpine Corporation, Middletown, CA, USA corp_creators: Calpine Corporation, Middletown, CA, USA corp_creators: Calpine Corporation, Middletown, CA, USA corp_creators: Calpine Corporation, Middletown, CA, USA corp_creators: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA, USA corp_creators: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA, USA corp_creators: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA, USA title: The Northwest Geysers EGS Demonstration Project, California Part 1: Characterization and reservoir response to injection subjects: MP2 subjects: MP4 subjects: RU1_1 subjects: SG divisions: SHEER-5 full_text_status: none keywords: Enhanced Geothermal Systems; The Geysers; Induced seismicity; Reservoir stimulation; Shear zones abstract: An Enhanced Geothermal System (EGS) Demonstration Project is currently underway in the Northwest Geysers. The project goal is to demonstrate the feasibility of stimulating a deep high-temperature reservoir (HTR) (up to 400 °C, 750 °F). Two previously abandoned wells, Prati State 31 (PS-31) and Prati 32 (P-32), were reopened and deepened to be used as an injection and production doublet to stimulate the HTR. The deepened portions of both wells have conductive temperature gradients of 10 °F/100 ft (182 °C/km), produce connate native fluids and magmatic gas, and the rocks were isotopically unexchanged by meteoric water. The ambient temperature meteoric water injected into these hot dry rocks has evidently created a permeability volume of several cubic kilometers as determined by seismic monitoring. Preliminary isotopic analyses of the injected and produced water indicate that 50–75% of the steam from the created EGS reservoir is injection-derived. date: 2015-09 date_type: completed publication: Geothermics volume: 63 publisher: Elsevier Science pagerange: 97-119 id_number: doi:10.1016/j.geothermics.2015.08.003 issn: 0375-6505 official_url: http://doi.org/10.1016/j.geothermics.2015.08.003 access_IS-EPOS: limited owner: Publisher citation: Garcia, Julio and Hartline, Craig and Walters, Mark and Wright, Melinda and Rutqvist, Jonny and Dobson, Patrick F. and Jeanne, Pierre (2015) The Northwest Geysers EGS Demonstration Project, California Part 1: Characterization and reservoir response to injection. Geothermics, 63. pp. 97-119. DOI: https://doi.org/10.1016/j.geothermics.2015.08.003