There is great worldwide drive for renewable green energy. By 2020, California is mandated to have 33 percent of its electricity from renewable resources. Here we present two papers. The first describes the world’s largest heat mining operation using treated sewage fluids flashed to steam. The second is about the California Energy Commission’s efforts to help operators develop geothermal energy from produced oil and gas fluids in the Los Angeles Basin.
From Flush to Flash- Renewable Green Energy from Treated Sewage Fluids:
The Geysers Geothermal field, the largest geothermal field in the world, is about 160 km north of San Francisco. The field started production in 1960 with a 12 MWe power plant. By 1987, steam production peaked at 112 billion kg, generating approximately 1,500 MWe. A rapid decline in production ensued. At that point, the cumulative mass replacement rate (i.e., the fluid re-injection rate) was only about 25%, resulting in reservoir dry-out and superheat. Without additional recharge, about 33% of the recoverable heat-energy could be extracted. However, with injection, a major heat mining operation could start. Yet there was no water except for the cooling tower recoveries and seasonal streams.
For many years, Lake County and the City of Santa Rosa (Sonoma County) had been looking for avenues to dispose their treated effluent. Since The Geysers was in need of water and the county and city needed an effluent disposal outlet, a unique public-private collaboration began. In 1997, Lake County constructed a 42-km-long pipeline to transport 1.01 million kg of secondary treated effluent per month to The Geysers for injection, which resulted in additional steam. This prompted Santa Rosa and other municipalities in Sonoma County to construct a similar pipeline. By the end of 2003, the Santa Rosa pipeline was completed, resulting in an additional 1.25 million kg of tertiary treated effluent to The Geysers every month. The current mass replacement from both pipelines and other sources is about 85% of production. This has resulted in sustained steam production, a decrease in non-condensable gases, improved electric generation efficiency, and lower air emissions. The additional electricity generated as a result of these two pipelines is about 155 MWe per year. The Geysers has become the largest heat mining operation in the world. Locally this success story is called “Flush to Flash.”
Bio – Ali Kahn:
Khan is an Operations and Permitting Supervisor for the State of California, Department of Conservation's Division of Oil, Gas, and Geothermal Resources (DOGGR) in the Cypress district. In this capacity, he oversees permitting, drilling, production and injection operations in the Los Angeles Basin, and promotes public health and safety through public meetings and dissemination of technical data. Prior to his current appointment, he was Geothermal District Engineer for the DOGGR Santa Rosa office. Khan earned his BS and MS degrees from the Middle East Technical University, Ankara, Turkey. For 35 years Khan has worked in upstream oil, gas, and geothermal projects in Turkey, Pakistan, Germany, and the United States Gulf Coast. Khan received the American Association of Petroleum Geologists’ Gulf Coast Section’s “Best Paper” and “Levorson” awards for “New Ideas in Exploration of Oil and Gas,” as well as the Department of Conservation’s “Superior Accomplishment Award.”
Geothermal Energy Co- Production from Oil and Gas Wells in Los Angeles Basin:
California's electricity system faces several important problems. One problem is insufficient generating capacity to accommodate projected needs. A second major problem is transmission congestion: insufficient transmission and distribution (T&D) infrastructure compounds the generating capacity problem, especially in high-demand centers of the state. Voltage dips and outages resulting from capacity shortages lead to power flow anomalies that create even further local electricity flow bottlenecks and power quality problems. A third issue is the mandated requirement to increase the proportion of renewable energy sources into the State’s energy mix and to reduce the emission of greenhouse gases. Another part of the problem is the relative lack of a diversified resource and generation supply system. California remains dependent on fossil fuel sources, natural gas in particular, as its major source of energy generation, leaving the state with little insulation from possible (deleted future) supply disruptions and the associated price shocks. A possible solution to current and future electricity system problems is increased distributed generation through the development of geothermal energy resources in oil and gas fields.
Bio – Pablo S. Gutierrez:
Mr. Gutierrez is the Geothermal Program Technical Lead, for the California Energy Commission (CEC) located in Sacramento, California. As the Geothermal Program Lead his responsibilities includes administration and management of the Geothermal Program which finances and promotes research, development, demonstration and commercialization of geothermal technologies through grants with private companies, utilities, universities, and governmental agencies. Previous to his tenure with the CEC, Mr. Gutierrez was employed by the California Environmental Protection Agency (CalEPA) where his duties centered on construction management of wastewater treatment projects. Prior to Mr. Gutierrez’s employment with the CalEPA, he was employed by Southern Gas Company where his assignments included analysis of natural gas pipelines and distribution systems, pipeline construction, operation and maintenance, and monitoring and failure analysis. As an undergraduate, Mr. Gutierrez worked for Union Oil Company where he participated in various research projects including determining scaling, corrosion and erosion rates, and failure mechanisms of nickel-alloy and low carbon steel pipeline, injection pumps and wells exposed to high pressure and high temperature brines, and pipeline operation and maintenance. Mr. Gutierrez is a Mechanical Engineer, attended undergraduate and graduate school at California State University, Fresno. He has co-authored a variety of technical papers related to geothermal energy.