Oil and Gas Expertise for Geothermal Exploitation: The Need for Technology Transfer

Abstract

Renewable energy is seen as the future source to meet the world's growing demand, with geothermal resources offering a constant and independent supply. Over the past century, the oil and gas sector has developed high level technologies for the exploitation of hydrocarbon reservoirs and this expertise should be directly transferrable to geothermal exploitation. In contrast to hydrocarbon developments, geothermal projects typically only become economic after decades of operation, which implies a long period of debt service before costs can be recovered from the sale of energy in the form of heat, electricity or a combination of both. Thus, the technology transfer between the petroleum and geothermal sectors has not been as efficient as initially hoped for. This paper begins with a review of the principles and uses of geothermal energy in today's sustainable energy scenario, from District Heating systems to the more recent Hot Dry Rock (HDR) concept. As exploiting HDR resources becomes more economic, the geothermal energy resources of countries like the U.S. could meet domestic demand for electricity for thousands of years. The challenges presented by HDR projects around the world are discussed, with a special focus on those aspects of geothermal exploitation that overlap with the oil and gas expertise, such as drilling and completions practices, the characterization of fluid flow through porous media and in wellbores and reservoir fracturing issues. The comparison shows how hydrocarbon exploration and production complements that of geothermal exploitation and identifies technical areas where future research efforts should be addressed to enhance the technology transfer between these energy sectors. Introduction Geothermal energy is a renewable source that becomes economically more attractive as the cost of conventional energy increases. The exploitation of geothermal resources incurs many of the technical challenges that are encountered in oil and gas exploration and production. Although the concept of technology transfer between these energy sectors is not new, there is still scope for improvement in the way this transfer is being done, with the aim to create more synergy between the two areas of technology application. In what follows, a review of conventional and frontier geothermal energy uses is presented, which highlights current and future technological needs, and shows how these overlap with the oil and gas industry. The source of geothermal heat The planet's internal heat, which was originally generated by accretion from the gravitational binding of energy, has continued to grow with the decay of naturally occurring radioactive elements. The earth's flow of heat from its interior to its surface is currently around 45 TW. The earth cools at an extremely slow rate: the mantle's temperature has decreased by 300–350°C in 3 billion years, and the core remains at approximately 4000°C. About 99% of the earth is hotter than 10000C and 99% of the remaining 1% is hotter than 1000C. Fig. 1 illustrates the trends of temperature in the earth.

Unconventional Completion Design for Deep Geothermal Wells

“…The relevant topics in the fields of Geothermal Engineering and Petroleum Engineering are not so different, as the skills of geosciences, drilling and completion, reservoir engineering and production are needed for both, particularly for high temperature applications . Hence, it would behove the energy industry to tap into the synergy between these two sectors and improve the technology transfer (Falcone and Teodoriu, 2008).…”

The Identification of Growth Barriers for Exploitation of Geothermal Energy in China

“…Before actual drilling starts, legal procedures, such as permits, need to be acquired. During this phase, the lack of clear process to gain the access to the land and rights to explore and tap the underground heat make the process lengthy and complex, which might take several years' time (Ministry of Economic Development, 2010;Falcone and Teodoriu, 2008).…”

“…The Chinese government is supporting through policies to geothermal heating and heat pump manufacturing industry but more efforts are required for proper structuring of resource development, for instance, subsidy to the overall investment cost, a fixed feed-in tariff, reduction of tax, etc. As to the technical barriers, an advanced technology transfer from a traditional petroleum sector to geothermal sector might offer much convenience for a faster development of geothermal technologies (Falcone and Teodoriu, 2008;Reinicke et al, 2010). These technologies include the areas of geology and geophysics, drilling and completion, reservoir modeling, formation stimulation, and so on.…”

Experimental study on new structure teeth in a high-temperature environment

“…Geothermal resources have attracted extensive attention due to their advantages of being non-polluting and renewable. [1][2][3] With the increasing global energy consumption, nonrenewable energy sources are becoming more and more depleted. Finding renewable energy sources to replace non-renewable resources has become an important opportunity and challenge for humanity.…”