Characterization of Seismic Noise in an Oil Field Using Passive Seismic Data from a Hydraulic Fracturing Operation

2021 ◽  
Author(s):  
David Wendell Tomaz da Silva ◽  
Aderson Farias do Nascimento ◽  
Flavio Lemos de Santana
Keyword(s):  
Hydraulic Fracturing ◽  
Seismic Data ◽  
Seismic Noise ◽  
Oil Field ◽  
Passive Seismic

On bias and noise in passive seismic data from finite circular array data processed using SPAC methods

Geophysics ◽  
2006 ◽  
Vol 71 (6) ◽  
pp. V153-V162 ◽  
Author(s):  
Michael W. Asten
Keyword(s):  
Seismic Data ◽  
Seismic Noise ◽  
Imaginary Component ◽  
Empirical Measure ◽  
Restricted Range ◽  
Circular Array ◽  
Spatial Averaging ◽  
Seismic Arrays ◽  
Spectral Estimates ◽  
Passive Seismic

The finite nature of typical small seismic arrays used in conjunction with spatial autocorrelation (SPAC) processing for observing the microtremor wavefield causes predictable perturbations of the SPAC spectrum when sources of seismic noise are confined to a restricted range of azimuths. Such perturbations are especially evident at higher frequencies where wavelengths are on the order of the array radius. The effects are readily modeled and show that the triangular array geometries commonly used for microtremor studies require azimuthal distributions of wave energy on the order of [Formula: see text] or greater to have a high probability of being free of such perturbations. The imaginary component of the SPAC spectrum, which is ideally zero for a sufficiently dense circular array and/or a sufficiently isotropic wavefield, is in practice often nonzero and provides three quality-control indicators: (1) an indication of insufficient spatial averaging, (2) an empirical measure of the level of statistical uncertainty in SPAC spectral estimates, and (3) an indication of departures from plane-wave stationarity of the seismic noise wavefield.

scholarly journals Karst feature in Mishrif Reservoir and effect on drilling and production in Zubair oil field, Southern Iraq

2020 ◽  
Vol 10 (4) ◽  
pp. 19-32
Author(s):  
Hussein Saeed Almalikee ◽  
Hayder Kadhim Almayyahi ◽  
Methaq Khazal Al-Jafar
Keyword(s):  
Seismic Data ◽  
Economic Effect ◽  
Carbonate Reservoir ◽  
Oil Field ◽  
Static Data ◽  
Karst Feature ◽  
Negative Effect ◽  
Reservoir Connectivity ◽  
Southern Iraq

Karst features in the upper part of Mishrif carbonate reservoir can commonly create substantial vugs, pores and fissures and, thus, increasing the porosity and enhancing reservoir connectivity and permeability, this features were formed normally as a result of the carbonate rocks dissolution under the action of meteoric waters during very long periods of emersion spanning from Late Cenomanian to Turonian (about 4.5 Million years). This study deals with the presence of the karst features in Zubair oil field, southern Iraq, where Karst features were observed in the center and northern parts of the field close to the top of Mishrif Formation in most of the cored wells. Characterization of that feature can be achieved from static data at wellbore scale from core, and logs (conventional and non-conventional), and dynamic data such as mud losses, well tests combined with production logs (PLT) in addition to Seismic data. Beside the positive and economic effect of Karst, there is negative effect which includes causing mud losses during drilling in Mishrif Formation because of low reservoir pore pressure, Therefore, acid soluble cement plugs were used to heal that losses to continue drilling.

Integrating Active and Passive Seismic Data to Better Predict Hydraulic Fracturing

2014 ◽  
Author(s):  
Gabino Castillo ◽  
Kevin Chesser ◽  
Antoine Bouziat ◽  
Guy Oliver ◽  
Chi Vinh Ly ◽  
...  
Keyword(s):  
Hydraulic Fracturing ◽  
Seismic Data ◽  
Passive Seismic

scholarly journals HVSR Analysis of Rockslide Seismic Signals to Assess the Subsoil Conditions and the Site Seismic Response

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Alessia Lotti ◽  
Veronica Pazzi ◽  
Gilberto Saccorotti ◽  
Andrea Fiaschi ◽  
Luca Matassoni ◽  
...  
Keyword(s):  
Seismic Data ◽  
Seismic Noise ◽  
Spectral Ratio ◽  
Effect Of Temperature ◽  
Precipitation Trend ◽  
Seismic Signals ◽  
Rock Falls ◽  
Time Frequency ◽  
Passive Seismic ◽  
On Line

Many Italian rock slopes are characterized by unstable rock masses that cause constant rock falls and rockslides. To effectively mitigate their catastrophic consequence thorough studies are required. Four velocimeters have been placed in the Torgiovannetto quarry area for an extensive seismic noise investigation. The study area (with an approximate surface of 200×100 m) is located near the town of Assisi (Italy) and is threatened by a rockslide. In this work, we present the results of the preliminary horizontal to vertical spectral ratio analysis of the acquired passive seismic data aimed at understanding the pattern of the seismic noise variation in case of stress state and/or weathering conditions (fluid content and microfracturing). The Torgiovannetto unstable slope has been monitored since 2003 by Alta Scuola of Perugia and the Department of Earth Sciences of the University of Firenze, after the observation of a first movement by the State Forestry Corps. The available data allowed an extensive comparison between seismic signals, displacement, and meteorological information. The measured displacements are well correlated with the precipitation trend, but unfortunately no resemblance with the seismic data was observed. However, a significant correlation between temperature data and the horizontal to vertical spectral ratio trend of the seismic noise could be identified. This can be related to the indirect effect of temperature on rock mass conditions and further extensive studies (also in the time frequency domain) are required to better comprehend this dependency. Finally, the continuous on-line data reveal interesting applications to provide near-real time warning systems for emerging potentially disastrous rockslides.

scholarly journals Seismic characterization of fractured reservoirs by focusing Gaussian beams

Geophysics ◽  
2013 ◽  
Vol 78 (4) ◽  
pp. A23-A28 ◽  
Author(s):  
Yingcai Zheng ◽  
Xinding Fang ◽  
Michael C. Fehler ◽  
Daniel R. Burns
Keyword(s):  
Seismic Data ◽  
Fractured Reservoirs ◽  
Oil Production ◽  
Oil Field ◽  
Critical Parameters ◽  
Gaussian Beams ◽  
Fractured Reservoir ◽  
Fracture Orientation ◽  
Double Beam

Naturally fractured reservoirs occur worldwide, and they account for the bulk of global oil production. The most important impact of fractures is their influence on fluid flow. To maximize oil production, the characterization of a fractured reservoir at the scale of an oil field is very important. For fluid transport, the critical parameters are connectivity and transmittivity plus orientation. These can be related to fracture spacing, compliance, and orientation, which are the critical seismic parameters of rock physics models. We discovered a new seismic technique that can invert for the spatially dependent fracture orientation, spacing, and compliance, using surface seismic data. Unlike most seismic methods that rely on using singly scattered/diffracted waves whose signal-to-noise ratios are usually very low, we found that waves multiply scattered by fractures can be energetic. The direction information of the fracture multiply scattered waves contains fracture orientation and spacing information, and the amplitude of these waves gives the compliance. Our algorithm made use of the interference of two true-amplitude Gaussian beams emitted from surface source and receiver arrays that are extrapolated downward and focused on fractured reservoir targets. The double beam interference pattern provides information about the three fracture parameters. We performed a blind test on our methodology. A 3D model with two sets of orthogonal fractures was built, and a 3D staggered finite-difference method using the Schoenberg linear-slip boundary condition for fractures was used to generate the synthetic surface seismic data set. The test results showed that we were able to not only invert for the fracture orientation and spacing, but also the compliance field.

A two-stage procedure for the automated identification of micro-earthquakes: implementation on single-station 3C passive seismic data

2020 ◽  
Vol 224 (3) ◽  
pp. 1705-1723
Author(s):  
A Lois ◽  
F Kopsaftopoulos ◽  
D Giannopoulos ◽  
K Polychronopoulou ◽  
N Martakis
Keyword(s):  
Decision Making ◽  
Characteristic Function ◽  
Seismic Data ◽  
Seismic Noise ◽  
Real Data ◽  
Singular Values ◽  
False Alarms ◽  
Data Sets ◽  
Single Station ◽  
Passive Seismic

SUMMARY In this paper, we propose a two-step procedure for the automated detection of micro-earthquakes, using single-station, three-component passive seismic data. The first step consists of the computation of an appropriate characteristic function, along with an energy-based thresholding scheme, in order to attain an initial discrimination of the seismic noise from the ‘useful’ information. The three-component data matrix is factorized via the singular value decomposition by means of a properly selected moving window and for each step of the windowing procedure a diagonal matrix containing the estimated singular values is formed. The ${L_2}$-norm of the singular values resulting from the above-mentioned windowing process defines the time series which serves as a characteristic function. The extraction of the seismic signals from the initial record is achieved by following a histogram-based thresholding scheme. The histogram of the characteristic function, which constitutes its empirical probability density function, is estimated and the optimum threshold value is chosen corresponds to the bin that separates the above-mentioned histogram in two different areas delineating the background noise and the outliers. Since detection algorithms often suffer from false alarms, which increase in extremely noisy environments, as a second stage, we propose a new ‘decision-making’ scenario to be applied on the extracted intervals, for the purpose of decreasing the probability of false alarms. In this context, we propose a methodology, based on comparing among autoregressive models estimated both on isolated seismic noise, in addition to the detections resulting from the first stage. The performance and efficiency of the proposed technique is supported by its application to a series of experiments that were based on both synthetic and real data sets. In particular, we investigate the effectiveness of the characteristic function, along with the thresholding scheme by subjecting them to noise robustness tests using synthetic seismic noise, with different statistical characteristics and at noise levels varying from 5 down to –5 dB. Results are compared with those obtained by the implementation of a three-component version of the well-known STA/LTA algorithm to the same data set. Moreover, the proposed technique and its potential to distinguish seismic noise from the useful information through the proposed decision making scheme is evaluated, by its application to real data sets, acquired by three-component short-period recorders that were installed for monitoring the microseismic activity in areas characterized by different noise attributes.

ORGANIC COMPOUND CHARACTERIZATION OF HYDRAULIC FRACTURING FLOWBACK WATERS THROUGHOUT THE FRACTURING PROCESS

2016 ◽  
Author(s):  
Karl Oetjen ◽  
◽  
Simon Roberts ◽  
Tzahi Y. Cath ◽  
Chris Higgins
Keyword(s):  
Organic Compound ◽  
Hydraulic Fracturing ◽  
Fracturing Process
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