Jim Rutledge is part of the Utah FORGE seismic monitoring team lead by Dr. Kristine Pankow at the University of Utah. He brings to the Team an expertise in downhole seismic instrumentation and the monitoring of reservoir microseismicity induced during injection stimulations.
An Enhanced Geothermal reservoir is created and or enhanced through a series of high-pressure injections to fracture, stimulate and connect natural fractures in the host rock. Such a fracture system provides the permeability and surface area required to circulate fluids for mining the earth’s heat. Detecting and locating the resulting microseismicity is the chief diagnostic used to map and monitor the development of that fracture system. In addition to obtaining the basic geometry of the stimulated fracture volume and its temporal growth, geomechanical information can be gleaned from source mechanism results, describing the fracture orientation and sense of displacement that generated the seismic signal.
Jim was employed as an Industry Advisor with Schlumberger’s Microseismic Services for the last 8 years before recently partnering with the FORGE team. At Schlumberger he worked primarily on the interpretation of moment tensor inversion in understanding the basic relationship between fracture propagation and generation of the microseismic signal. He spent most of his career, from 1984 to 2012, as a staff seismologist at Los Alamos National Laboratory. From 2004 to 2012 he also worked as a consultant for Schlumberger Cambridge Research. He received a BS in Geology from Pennsylvania State University and an MS in Geophysics from the University of Arizona. Starting in 1989, Jim has led and participated in several studies that demonstrated the uses of microseismic monitoring in oil, gas and geothermal fields for various applications including: hydraulic fracture monitoring, EOR monitoring, production-induced seismicity, subsidence and well-failure problems, gas storage, as well as subsurface CO2 sequestration. He is widely published on the topic of downhole seismic monitoring and interpretation.
An example of microseismic source locations from numerous injection stimulation stages in map view (left) and the population of source mechanisms for the stage 7 events (right). The lateral completion well is shown red.
Did you know… that Reykjavík is a city of geothermal energy?
Did you know that the city of Reykjavík, the capital of Iceland, is widely recognized for its geothermal energy? Many first think of the word ‘ice’ when hearing Iceland, but surprisingly Iceland is also known for its use of Earth’s heat. Due to its geological location directly on the mid-Atlantic ridge, it is constantly supplied by an enormous amount of underground magmatic and geothermal heat. The literal translation of Reykjavík is “steamy bay” that comes from the steam discharge associated with natural geothermal activity.
Aware of the underground heat available, Icelanders have learned to adapt to their environment. Since the arrival of the first Scandinavian settlers in the late 800s, Icelanders have utilized geothermal sources for bathing and cooking. One of their popular traditional foods, Hverabrauð, is a bread loaf cooked in the steam from a geyser for 24 hours. Up into the early part of the 20th century, coal was the main source of energy and air pollution was a serious problem. To address this, the first geothermal pipelines were installed in 1934, and since then Reykjavík has been continuously expanding geothermal utilization. Reykjavík now has the largest district heating system in the world (700 MWthermal), which is run by Orkuveita, and more than 60 million cubic meters of hot water flow through the distribution system. Hot water supply comes from low temperature geothermal areas around Reykjavik and from high temperature geothermal fields in the Hengill area to the east of the city. These hotter resources are mainly used to generate electricity, but a significant amount of heat also supplies the district heating scheme. The combination of geothermal fields and hydroelectric dams means that more than 99% of all the electricity used in Iceland comes from renewable sources.
Did you know that some species incubate their eggs using geothermal heat?
Megapodes represent a family of birds that are also known as incubator birds. They are found across Australasia, and they are known for their unique strategies to keep their eggs warm and safe. Depending on the local environment, incubating strategies range from building a massive nest with stacks of decaying vegetation to laying eggs in warm ground heated by the sun. Certain species of megapode occurring on volcanic islands in the Bismarck archipelago, Solomon Islands, Vanuatu, Tonga, and Micronesia bury and incubate their eggs in geothermally heated ground. Megapodes originated in Australia, and as they evolved, they spread northward and eastward to tropical islands of the southwest Pacific. The use of thermal ground by just a few species of Megapode to incubate eggs appears to be simply a matter of opportunity.
The incubation of eggs in thermal ground, however, is not just for the birds. Their ancient ancestors, dinosaurs, may have been similarly opportunistic. The recently discovered Sangasta nesting site in northwest Argentina provides definitive evidence that neosaupods used geothermally heated ground to incubate their eggs. Much like humans, some animals have used geothermal heat when and where it is easily available.
Grellet-Tinner, G. and Fiorelli, L.E., 2010, A new Argentinian nesting site showing neosauropod dinosaur reproduction in a Cretaceous hydrothermal environment: Nature Communications, 1:32, DOI: 10.1038/ncomms1031
Harris, R.B., Birks, S.M. and Leaché, A.D., 2014, Incubator birds: biogeographical origins and evolution of underground nesting megapodes (Galliformes: Megapodiidae): Journal of Biogeography, v. 41, p. 2045-2056.
Geothermal energy has great benefits for people, but did you know that there are animals that use natural thermal heat in the form of hot springs and warm ground?
Macaques, better known as snow monkeys, are found throughout the main Japanese Island of Honshu, and they are famous for soaking in local volcanic hot springs. Their bathing habit is a recent phenomenon that was first observed at Korakukan Onsen, a local guest house, in 1962. Snow monkeys seem to have adapted this habit from observing humans in the hot springs. Since then, this behavior has been passed onto rest of their troops, and it has now become a part of their daily routine. Snow monkeys bathe in hot springs to preserve body heat to survive the cold and rigid winters, but recent studies have proven they also do this as a form of stress relief.
Matsuzawa, T., 2918, Hot-spring bathing wild monkeys in Shiga-Heights: origin and propagation of a cultural behavior: Primates, v. 59, p. 209-213.
Takeshita, R.S.C., Bercovitch, F.B., Kinoshita, K. and Huffman, M.A., 2018, Beneficial effect of hot spring bathing on stress levels in Japanese macaques: Primates, v. 59, p. 215-225.
The utilization of geothermal heat as an energy resource, e.g., to heat (or cool) a building such as a greenhouse, for drying, for manufacturing.
An operation carried out on a well that increases production or injection by improving the flow characteristics of the reservoir and enhancing the flow between the reservoir and the wellbore
Did you know that the direct use of geothermal energy can be used to raise alligators?
The direct use of geothermal energy can apply to almost any activity that requires heating (and cooling) for industrial, residential and agricultural purposes. The heat is transferred by hot ground water in the temperature range of 20-120°C (70-250°F) which is produced from shallow wells and then distributed through surface pipework. One very popular direct use application of geothermal energy is for bathing in natural hot springs. Spas all over the world use naturally produced hot water for recreational and therapeutic purposes. In Utah, the Crystal Hot Springs offers warm and mineral-rich baths which attracts numerous visitors throughout the year.
Another direct use application is space heating that may serve a single, stand-alone structure, or more commonly multiple buildings, which are linked by a pipeline that supplies hot water. For regions that are subject to cold winters, this is a cost effective means of heating without contributing to atmospheric pollution. District heating has been in use since the late 1890s when the city of Boise, Idaho started using geothermal energy to heat buildings. District heating is also popular in China, Iceland, France, Germany, Hungary and New Zealand. In the state of Utah, the prison at the Point of the Mountain uses district heating for 330,000 sq. ft. of prison space, saving thousands of dollars over conventional heating systems.
This type of geothermal energy is even used to heat greenhouses to grow plants. The Milgro complex in Newcastle, Utah is one of the largest producers of poinsettias and chrysanthemums in the USA; it uses geothermally heated greenhouses to grow its flowers. This type of energy is also used to heat ponds for aquaculture and fish farming. The warm springs near Grantsville, Utah are filled with warm, mineral-rich water that supports a variety of fish and are also an attraction for scuba-diving activities. Fish breeders in Idaho farm a range of species, including ones requiring geothermally heated ponds, which famously once included alligators!
A mechanical-compression cycle system that can be reversed to either heat or cool a controlled space