Long-term monitoring of microseismic emissions: Earth tides, fracture distribution, and fluid content

Abstract

Monitoring of microseismic emissions for periods of 10–30 days has established a clear relationship between solid earth tides and microseismic activity. In addition, an event magnitude versus recurrence relationship has been established that can be used to predict oil, gas, or water content of open fractures in imaged rock volumes. Originally developed to explore for oil and gas, the detection technology used has been applied in Eurasia, the Middle East, and Texas. When visualized in three dimensions at scales of several kilometers on a side, including depth, the observations shows systems of subvertical fracture volumes distributed as clusters in the subsurface. When visualized in sequential time windows, microseismic activity can be seen to respond in detail to lunar-solar gravitational changes. The seismic imaging technology used to detect the location and temporal changes within these fracture systems is based on deploying geophone receiver arrays using array patterns and processing algorithms similar to those used in phased array radar in the electromagnetic spectrum. This passive listening technology has been termed seismic location of emission centers (SLEC). Examples of applied SLEC monitoring are presented for surveys performed in Russia and Texas.

Man-made earthquakes prevention through monitoring and discharging their causative stress-deformed states

“…Reliable estimates of the geologic properties can thus be made from MSE statistical measures. (Kouznetsov, et al, 2016). For a better understanding of the dynamics of the anomalous MSE zones, time slices of the MSE 3D cube were generated (Fig.…”

“…implemented from the surface (close to the wellhead) using a seismic vibrator SV-10/100 transmitting sweep signals at lowto-mid frequencies (17)(18)(19)(20)(21)(22)(22)(23)(24)(25)(26)(27)(27)(28)(29)(30)(31)(32)(32)(33)(34)(35)(36)(37) Hz) continuously for 90 seconds in each sweep. The integrated intensity of seismo-acoustic emission (SAE) was measured by a downhole noise-meter with operating within a relatively high frequency range of 100 Hz -10 kHz continuously, starting with the first cycle of seismic stimulation.…”

“…shows the processed seismic wave field that was continuously acquired over 11-day period at 2-hour time intervals near one of the shale oil fields in the state of Texas,Kouznetsov (2016). The averaged mean energy acquired over the 11-day period was presented as a 3D cube.…”

“…This example shows the ability of the SLEC technology to identify and monitor the MSE anomalous zones, size, intensity and dynamics. Example of 3D-distribution of MSE mean energy (within the 48-hour) estimated from SLEC acquisition(Kouznetsov et al, 2016). Example shown is from Texas (USA).Nat.…”

On the use of the microtremor HVSR for tracking velocity changes: a case study in Campo de Dalías basin (SE Spain)

“…The mechanism on how these changes are induced is what is holding current discussions. Some authors point to source mechanisms like thermoelastic strains or solid earth tides (Snieder et al, 2002;Takano et al, 2014;Hillers et al 2014Hillers et al -2015Kouznetsov et al, 2016;Lotti et al 2018;Chaput et al, 2018;Miao et al, 2019). Nevertheless, others find in the variability of wavefield composition or source location the explanation for their observations (Kraeva et al, 2009;Stutzman et al, 2009;Zhan et al, 2013;Lepore et al, 2016;Gualtieri et al, 2018;Dybing et al, 2019;La Rocca et al, 2020).…”