Method for detection of subsurface seismic events in vertically transversely isotropic media

An event, surface technique, applied in seismology for well logging, seismology for areas covered by water, seismology, etc., can solve problems such as bias

Inactive Publication Date: 2013-05-15
MICROSEISMIC
View PDF3 Cites 12 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Scaling up isotropic velocities can provide locally similar localization accuracies for drill-and-blast, however, if drill-and-blast or microseismic events occur at significantly different lateral locations, since the receiver quiescent state is only tuned to the selected Calibration position, the foregoing approximation may produce biased results

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method for detection of subsurface seismic events in vertically transversely isotropic media
  • Method for detection of subsurface seismic events in vertically transversely isotropic media
  • Method for detection of subsurface seismic events in vertically transversely isotropic media

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0017] The method according to the invention will be described generally, with particular reference to the example of its use in monitoring the progress of a subsurface fracturing treatment of a rock formation. Subsequently, a specific case study of an example implementation will be described. In the described case study, the initial velocity model was a layered 1D isotropic model derived from a surface seismic check blast survey, however, the technique is generally applicable to 3D media. Because check blast surveys typically only provide seismic information from a single offset (source to sensor distance), the velocity model has to be smoothed to represent a 1D isotropic layered model of the rock formation. In this example case study, such models had to be artificially multiplied by a factor of 1.25 to locate a calibration shot (ie, a drilling munition detonated at a known time and location). However, this approach is inconsistent with what is known about the physics of sou...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

A method for determining positions and origin times of seismic events occurring in the Earth's subsurface includes accepting as input to the method signals recorded from a plurality of seismic sensors deployed above a subsurface volume of interest. The recorded signals are a representation of seismic amplitude with respect to time. Origin time and location of each of a plurality of subsurface seismic events are determined from the recorded signals. The origin times and locations of each event are inverted to obtain Thomsen's parameters in formations in the volume of interest. Depths of each of the events are determined by individually searching the depth of each event, the inversion with each incorporated new depth including updating the Thomsen parameters and setting as a limit a minimum value of RMS error.

Description

field of invention [0001] The present invention relates generally to the field of passive detection and imaging of seismic events occurring subsurface. More specifically, the present invention relates to such techniques as may be applied in rock formations having transverse isotropy ("VTI") with a vertical axis of symmetry. Background technique [0002] Passive seismic emission tomography is a process in which arrays of seismic sensors are deployed in selected patterns on or near the Earth's surface (or on the seabed in oceanographic surveys) and from within the Earth's subsurface Seismic energy emitted by various seismic events is detected at the sensor. Processing of signals detected by sensors is used, inter alia, to determine the location of various seismic events within the Earth's subsurface, the mechanism of formation failure, and the timing of such events. [0003] Applications of passive seismic emission tomography include, for example, the determination of motion...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): G01V1/28
CPCG01V2210/586G01V1/288G01V1/42G01V1/38G01V2210/1234G01V2210/65
Inventor Y.张L.埃斯纳
Owner MICROSEISMIC
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products