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Dive into the research topics where Norm Warpinski is active.

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Featured researches published by Norm Warpinski.


Geophysical Prospecting | 2014

Full‐waveform based microseismic event detection and signal enhancement: An application of the subspace approach

Fuxian Song; Norm Warpinski; M. Nafi Toksöz; H. Sadi Kuleli

Microseismic monitoring has proven invaluable for optimizing hydraulic fracturing stimulations and monitoring reservoir changes. The signal to noise ratio of the recorded microseismic data varies enormously from one dataset to another, and it can often be very low, especially for surface monitoring scenarios. Moreover, the data are often contaminated by correlated noises such as borehole waves in the downhole monitoring case. These issues pose a significant challenge for microseismic event detection. In addition, for downhole monitoring, the location of microseismic events relies on the accurate polarization analysis of the often weak P-wave to determine the event azimuth. Therefore, enhancing the microseismic signal, especially the low signal to noise ratio P-wave data, has become an important task. In this study, a statistical approach based on the binary hypothesis test is developed to detect the weak events embedded in high noise. The method constructs a vector space, known as the signal subspace, from previously detected events to represent similar, yet significantly variable microseismic signals from specific source regions. Empirical procedures are presented for building the signal subspace from clusters of events. The distribution of the detection statistics is analysed to determine the parameters of the subspace detector including the signal subspace dimension and detection threshold. The effect of correlated noise is corrected in the statistical analysis. The subspace design and detection approach is illustrated on a dual-array hydrofracture monitoring dataset. The comparison between the subspace approach, array correlation method, and array short-time average/long-time average detector is performed on the data from the far monitoring well. It is shown that, at the same expected false alarm rate, the subspace detector gives fewer false alarms than the array short-time average/long-time average detector and more event detections than the array correlation detector. The additionally detected events from the subspace detector are further validated using the data from the nearby monitoring well. The comparison demonstrates the potential benefit of using the subspace approach to improve the microseismic viewing distance. Following event detection, a novel method based on subspace projection is proposed to enhance weak microseismic signals. Examples on field data are presented, indicating the effectiveness of this subspace-projection-based signal enhancement procedure.


Geophysical Research Letters | 2013

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

Samuel A. Flewelling; Matthew P. Tymchak; Norm Warpinski


Archive | 2011

SUBTERRANEAN FLOW BARRIERS CONTAINING TRACERS

Alvin Stanley Cullick; Leldon Mark Farabee; Norm Warpinski; Robert F. Shelley; Stewart A. Levin


Geophysics | 2014

Full-waveform based microseismic source mechanism studies in the Barnett Shale: Linking microseismicity to reservoir geomechanics

Fuxian Song; Norm Warpinski; M. Nafi Toksöz


Geophysics | 2011

Uncertainty in FPSs from moment-tensor inversion

Jing Du; Norm Warpinski


Archive | 2012

ENHANCED GEOTHERMAL SYSTEMS AND METHODS

Ronald E. Sweatman; Jason L. Pitcher; Norm Warpinski; Mark Stephen Machala; Joel D. Shaw


Geophysics | 2014

Microseismic monitoring — The key is integration

Norm Warpinski


Archive | 2013

Seismic Energy Sources and Methods of Use

Mark Willis; Erkan Ay; Norm Warpinski; Tianrun Chen


Seg Technical Program Expanded Abstracts | 2014

Microseismic Anisotropic Velocity Calibration by Using Both Direct and Reflected Arrivals

Donghong Pei; James Carmichael; Charlie Waltman; Norm Warpinski


Seg Technical Program Expanded Abstracts | 2013

Anisotropic Effects on Polarization From Highly Deviated / Horizontal Wells in Microseismic Monitoring of Hydraulic Fractures

Jing Du; Norm Warpinski; C. Waltman

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M. Nafi Toksöz

Massachusetts Institute of Technology

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Fuxian Song

Massachusetts Institute of Technology

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H. Sadi Kuleli

Massachusetts Institute of Technology

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