Research Of Forward Simulation And Inversion Of Positioning Of Microseismic

Microseismic monitoring is a technology that Monitor the Effects of productionactivities and Reservoir state by observing and analysing the micro seismic events inproduction activities, As an effective monitoring technique for locating the microfractures of the rock, it’s widely used in fields like mining dynamic disastermonitoring etc.From the perspective of the acoustic emission of rock, when thedisturbances outside have effects on solid materials(the temperature or payloadchanges), the concentration phenomenon of the local stress appear inside, whenmaterial strength inside is insufficient, deformation and microcosmic damage will becaused by the high local energy state. Accumulations and expansions of microdamages Cause macroscopic crack, then the Internal stability failure appears.Accumulations and expansions of micro damages will also the cause Savings of burstmode(Non steady and continuous),and the energy releases in elastic wave, thisphenomenon is often called rock acoustic emission. Generally, the low frequency(below1kHz) acoustic emission of rock due to the long-term geological explorationdue to the long-term geological exploration and mining damage to the surroundingrock structure is called microseismic.Different from the traditional seismic exploration, in microseismic monitoring,the location, time and strength of microseismic source is unknown, determination ofthese unknown factors is the primary task of microseismic monitoring.This cause thedifferences in fields of application between the traditional seismic exploration andMicroseismic monitoring,in summary, Microseismic monitoring is used as follows:(1)Reservoir dynamic monitoring;(2) Reservoir fracture monitoring;(3) Recognition ofthe cracks or faults may cause early to see the water flow channel or the dividing ofreservoir area,describe the plugging performance of faults;(4) For fracturedreservoir,we can use it as the effective transverse wave and longitudinal wave sourcelocated within the reservoir to analyse shear wave anisotropy and image velocity,image anisotropic of flowing on the fractured reservoir;(5) Research onfocal mechanism and waveform of microseismic, providing information onconductive cracks inside the reservoir, deformation mechanism, the moving situationof pressure front and the fluid flow distribution.Forward modeling of microseismic is the foundation of microseismic monitoringtechnology, and an effective tool to validate kinematics of the microseismic wavefield and check the correctness all kinds of Microseismic monitoringmethods.Through the results of forward modeling, The algorithm can bemodified,microseismic location precision will increase, it provide effective theoreticalbasis for accurate inversion of unknown structure formation.In this paper, the model isthe simple layered model, microseismic locations and excitation time is set in advance,then simulate the Microseismic signal acquisition process and seismic signals thepretreatment process,Obtain seismic profile data and snapshots of wavefield;According to the seismic profile data list the nonlinear equations about thesource location, Excitation time and Wave velocity, solve the equations with methodslike Newton iterative method etc, make the final result infinite close to the solutionof the equations,finally compare the solution of the equations with Snapshot of wavefield and seismic response, then we complete the whole simulation process.