Measurements of Hydraulic-Fracture-Induced Seismicity in Gas Shales

Abstract

Summary Hydraulic fracturing is an essential technology for hydrocarbon extraction from both conventional and unconventional reservoirs. Recently, concern has developed regarding induced seismicity generated in association with multistage fracturing of horizontal wells in shale reservoirs. Microseismic monitoring of hydraulic fractures, which has been a routine service for over a decade, can provide information about the levels of seismic activity commonly found during fracturing. A review of thousands of fracture treatments that have been microseismically monitored shows that the induced seismicity associated with hydraulic fracturing is very small and not a problem under any normal circumstances. Results are presented for six major shale basins in North America in which hundreds to thousands of fracture treatments have been conducted in predominatly gas reservoirs. This paper reviews the methodology, the data, and the interpretation of the microseismicity.

Myths and Facts on Wastewater Injection, Hydraulic Fracturing, Enhanced Oil Recovery, and Induced Seismicity

“…These intentionally produced earthquakes, often termed microseismic events, are typically on the order of −3:0 ≤ M ≤ 0 (Warpinski et al, 2012). In cases when hydraulic fracturing induces earthquakes of larger magnitudes, the earthquakes are likely the result of the reactivation of nearby pre-existing faults (Maxwell et al, 2010).…”

Hydraulic fracture height limits and fault interactions in tight oil and gas formations

“…[12] Seismic moments and areas of shear displacement were estimated for several of the most data-rich basins by Warpinski et al [2012] and are plotted in Figure 3. For comparison, seismic moment (M o = 16ΔσR 3 /7) was calculated for a range of static stress drops (Δσ), assuming all seismic events were shear displacements with circular slip areas of radius, R [Stein and Wysession, 2003].…”

Earthquakes Induced by Hydraulic Fracturing Are Pervasive in Oklahoma

“…While WD is the primary cause of induced earthquakes in the United States within the past decade, other human activities such as carbon sequestration (e.g., Kaven et al, 2015), geothermal energy (e.g., Johnson, 2014), and hydraulic fracturing (HF; e.g., Skoumal et al, 2015c) have also been attributed to seismicity. While microseismicity (M < 1) is an inherent component of the HF process (Warpinski et al, 2012;Wolhart et al, 2006), stimulations that induce larger-magnitude events along preexisting faults (HF-induced seismicity) are less common. HF-induced seismicity can also be differentiated from the inherent microseismicity by the locations of the events; the inherent microseismicity associated with fracture creation/opening are typically isolated near the formation being stimulated, while induced seismicity has been observed in the Precambrian basement or other sedimentary layers (e.g., Kozłowska et al, 2018).…”