Fiber-optic-based sensing technologies were first trialed for upstream oil and gas applications in the 1990s to monitor injection allocation of steam (Karaman, 1996). Beginning in the early 2000s, a broader range of applications was trialed from water injection profiling (Rahman et al., 2011) to acid injection profiling (Glasbergen et al., 2009) to hydraulic fracture diagnostics (Sierra et al., 2008). Since 2008, the use of fiber optics to analyze hydraulic fracturing has diversified substantially across unconventional reservoirs in North America. There has also been a diversification and maturity of the technologies. The primary technology used in the early works was distributed temperature sensing (DTS). To date, this technology is still the primary resource for fracture and production results for unconventional wells. However, technologies such as distributed acoustic sensing (DAS) (Molenaar et al., 2011) are becoming necessary to obtain complementary diagnostics to generate a more robust answer product.
This paper focuses on the fundamental value of information gained during the hydraulic fracturing process using fiber optics and the impact those learnings have had on future completion designs and decision making. There have been two dominant horizontal completion strategies in the unconventional market—cemented plug and perforation (PnP) completions and uncemented packer and sleeve (PnS) completions. Each of these types is reviewed to illustrate the value of information fiber optics has demonstrated, from the fracturing perspective. In this study, approximately 40 horizontal wells and 400 fracture stages are considered to provide an overview of the impact this technology has had on the industry understanding of completion effectiveness.