Review of Recent Unconventional Completion Innovations and Their Applicability to EGS Wells

Abstract

About a decade ago the technology breakthroughs of horizontal drilling and multi-stage hydraulic fracturing allowed the oil and gas industry to economically access major undeveloped resources. Many operators have now moved into a well manufacturing phase to develop these resources. Whilst often less publicized, the cumulative effect from countless novel technologies and process optimizations has resulted in dramatically reduced break-even costs. This paper provides a structured review and evaluation of technology innovations and operational learnings with a focus on the last 5 years. Examples of reviewed technologies with potential for future enhanced geothermal system (EGS) wells are downhole completion tools made of dissolvable metals and polymers. These materials have the potential to reduce stimulation time and costs. Furthermore changes in perforating design, advanced diversion tools and micro proppants have resulted in significant increases in the stimulated rock volume of shale wells. In regards to operational learnings, the paper evaluates amongst others the applicability of zipper frac operations in EGS projects. Leveraging these technologies for future EGS wells could enable the geothermal industry to dramatically improve project economics.