Fiber-optic Monitoring: Stimulation Results from Unconventional Reservoirs

Abstract

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.

Advancement of Hydraulic Fracture Diagnostics in Unconventional Formations

“…In most cases, these reservoirs are accessed through multistage horizontal wells where zonal isolation between different stages is imperative. Several published case studies [36,[43][44][45] demonstrate how DTS was able to diagnose a failure in isolation in horizontal wells. DTS is useful for identifying communication between stages.…”

“…These recordings can then be used to provide information such as fluid and proppant distributions for different perforation clusters along the wellbore during stimulation [8]. DAS applications such as ball tracking, injection/production profiling, cluster efficiency evaluation, and interstage communication rely on signal intensity in high-frequency bands [44,48,49]. DAS may also be used to conduct time-lapse vertical seismic profiles [50][51][52], to monitor microseismic events [53][54][55], and to measure cross-well strain variations [56].…”

Application of Fiber-optic Temperature Data Analysis in Hydraulic Fracturing Evaluation--A Case Study in Marcellus Shale

“…Downhole fiber-optics was used to provide continuous measurement of pressure and temperature for West Coalinga Field in California (Karaman & Kutlik, 1996). Other applications such as water injection surveillance, leak detection analysis, acid injection profiling, and hydraulic fracturing have been documented (Rahman, Zannitto, & Reed, 2011), (Glasbergen, Yeager, Reyes, & Everett, 2010), (Sierra , Kaura, Gualtieri, Glasbergen, Sarker, & Johnson, 2008), (Holley & Kalia, 2015).…”

Application and research progress of distributed optical fiber acoustic sensing monitoring for hydraulic fracturing

“…从国际最新技术发展应用趋势来看, 分布式光纤 传感监测已成为水力压裂监测的最新技术手段 [13] , 在 美国的页岩气等非常规资源开发中已经显示出重要作 用. 全球调查机构Grand View Research [14] 在2019年度 发布的关于光纤传感市场分析报告显示, 2018年全球 [20,21] , 成为非常规 储层水力压裂监测的热点技术.…”