Geothermal Utilization of Petroleum Wells: Methodology for Evaluating Electricity-Generation Potential and Economic Viability

  • Jamie Elizabeth Hutchins

Student thesis: Master's Thesis

Abstract

We evaluate the potential for electricity generation from geothermal energy in conjunction with petroleum development via two methods: co-production and well conversion. Co-production schemes consist of generating electricity from geothermal water that is produced along with the oil production. Well conversion schemes consist of repurposing oil wells as geothermal wells. Oilfields are typically characterized by sedimentary basins yielding geothermal gradients not adequate for commercial geothermal projects. However, recent improvements in turbine technology can produce viable electricity via lower-temperature geothermal resources. Utilizing existing oilfield data and infrastructure minimizes risk and up-front capital costs for small-scale geothermal projects. Benefits to the oilfield developer include reduced electricity and decommissioning costs, and reduced carbon emissions. A methodology is developed in this study to systematically evaluate the technical and economic viability of both co-production and well conversion schemes, which is then demonstrated in a case study of the San Miguelito Oilfield located in Ventura, California, United States. The San Miguelito Oilfield consists of a total of 270 active, idle, and plugged wells up to 5,029m deep. The site is characterized by a geothermal gradient of 2.6°C per 100m of vertical depth and an average ambient temperature of 16°C. Currently-active wells produced on average 9,500 barrels of oil, 170 million m3 of gas, and 12,775 barrels of water in 2011. Results of the case study at San Miguelito indicate that a co-production scheme is technically and economically viable while a well conversion scheme is neither in the San Miguelito case. A co-production scheme implemented at a single well (No. 801) and at an aggregated group both yielded positive NPV on the investment with payback periods of 7 and 5 years, respectively. The amount of electricity generated from the co-production scheme nearly offset the power needed to run the pumpjack used for oil production. Further, reducing net on-site power consumption and related electricity costs can improve oilfield economics and allow for prolonged economic petroleum production. A general perspective on the worldwide application of the methodology developed in this study is presented, as is commentary regarding the potential for geothermal desalination in conjunction with petroleum production in the United Arab Emirates.
Date of AwardMay 2012
Original languageAmerican English
SupervisorSgouris Sgouridis (Supervisor)

Keywords

  • Geothermal; Electricity Generation; Petroleum Wells; Economic viability.

Cite this

'