Newberry EGS Demonstration: Phase I Review
Phase I of the Newberry Enhanced Geothermal Systems Demonstration was a 20-month effort between May 2010 and March 2012. AltaRock Energy has published several papers detailing the process and results of this phase; one such report is available for download through the Stanford Geothermal Workshop website (PDF). This post is a summary of the information found in those reports.
There were eight major steps within Phase I of the demonstration: Historical data review, injection testing, hydrological testing, stimulation planning, public outreach, seismology, permitting, and next-phase planning.
We provide a high-level review of each step below, with links to additional resources where applicable; more detail is available in the full Phase I recap.
Historical Data Review
Before proposing an EGS Demonstration at Newberry Volcano to the Department of Energy (DOE), the AltaRock team reviewed geologic, geophysical, environmental, and social factors at ten different potential sites. Because Newberry Volcano has been an area of ongoing geothermal energy interest since the 1970s, it was one of the best characterized of the potential sites, with extensive geological and geophysical survey data as well as temperature and permeability data from a variety of exploratory wells.
After the DOE award was made in the fall of 2009, our team continued to review and synthesize the Newberry dataset in order design a successful stimulation. We also reviewed the operations and results of prior EGS projects in New Mexico, Japan, France, Switzerland, and Australia, in order to build on their success and avoid their mistakes.
Injection Testing and Borehole Televiewer Logging
Before we stimulate to create the EGS reservoir of small inter-connected cracks, we must determine the characteristics of the existing fractures which intersect the existing hot well, NWG 55-29.
In Phase I, we conducted injection testing to record the temperature profile, identify fluid level, and ensure the well was open to total depth. An injection test was conducted to measure the well’s baseline injectivity for comparison to the stimulated well. We also ran a high-resolution borehole televiewer (BHTV) which uses acoustic waves to image the walls of the borehole in the same way that a medical sonogram can image internal body parts. We’re pleased to report that the tests and image logs provided high quality data which indicate a high probability of success for the EGS Demonstration.
Because groundwater impact is the greatest public concern about the demonstration, AltaRock solicited an independent review of our water usage plan. This assessment was documented in a report, the Kleinfelder study, which found no significant impacts on the local groundwater supply.
Prior to, during, and after the stimulation we will monitor water levels in nearby wells, water composition throughout the stimulation area, the springs at Paulina and East Lakes, and the Paulina Lake domestic water well.
Stimulation planning and modeling was a large area of focus during Phase I. AltaRock has developed a sophisticated software (AltaStim) that uses the results of the injection test and BHTV image to simulate the process and results of stimulation (through a process called hydroshearing) at the demonstration site.
The modeling software has allowed us to generate microseismicity maps and calculate reasonable volumes and pressures for the water we inject during the stimulation process.
Our public outreach efforts began with four community meetings in communities throughout the state of Oregon. Each meeting provided a chance for the public to ask questions and raise any concerns they might have. The meetings allowed AltaRock to provide accurate, factual information to help answer residents’ questions.
Additional public outreach activities have included print, radio, and TV interviews and features; online publishing of project-related documents; a toll-free question line (855-USA4EGS); an animated project video, displays at the Newberry National Volcanic Monument, and an online social media presence (blog, Facebook, and Twitter).
Collecting the necessary data and developing a plan to satisfy the DOE’s protocol for addressing induced seismicity risk was a year-long effort. In Phase I of the demonstration, we performed a preliminary screening evaluation, implemented an outreach and communication program, indentified criteria for ground vibration and noise, established seismic monitoring, quantified the hazard from natural and induced seismic events, characterized the risk from induced seismic events, and developed a risk-based mitigation plan.
We submitted our Notice of Intent (PDF) for the demonstration to the Bureau of Land Management (BLM) in May of 2010. Since then, we have worked with the BLM, the US Forest Service, and the U.S. Department of Energy to ensure that the project plans met all requirements and were within all guidelines for responsible use of the land.
After our series of public meetings concluded, the BLM announced their initiation of the next step in the process: an official BLM Environmental Assessment of project plans. Their assessment was published on December 23, 2011 and followed by a 30-day public comment period from 12/23/11 to 1/25/12.
This week, the BLM will publish their response to the comments collected during that period, including their direction on whether the project plan will need adaptation in response to the comments. We will update our blog and website with an official recognition and response at that time.
Now that the planning and permitting Phase I is complete we are prepared to enter Phase II, and implement the detailed plans that have been developed and approved. We will publish Phase II steps for the Newberry Enhanced Geothermal Systems Demonstration in the near future. Until then, continue to read our blog and visit our website for additional information about the demonstration and AltaRock’s work.