Font Size: a A A

Automatic Identification And Pick Up Of Hydraulic Fracturing Microseismic Event

Posted on:2014-11-29Degree:MasterType:Thesis
Country:ChinaCandidate:L L WeiFull Text:PDF
GTID:2250330422461480Subject:Geological engineering
Abstract/Summary:PDF Full Text Request
Microseismic monitoring technology as a new geophysical technology, has been appliedin many fields, especially in oil and gas fields of low permeability are widely used in theprocess of mining. The microseismic monitoring technology of reservoir hydraulic fracturingis through the observation and analysising of microseismic events produced by humanproduction activities to high credibility determine the microseismic source location and itsseismogenic time, then according to the spatial distribution of reservoir fracturing cracks anddevelopment situation to objectively evaluate the effect of fractuiting and adjust fracturingparameters.The accuracy of source location based on travel time inversion is largely depended on thefist break pick up precision and the authenticity of microseismic events. Actual microseismicdata has a low signal-to-noise ratio and huge data, it’s strenuosity and slow to pick up firstbreak artificially, and it can’t meet the requirements of on-site real-time processing. So, themethod and the software technology of the automatic identification and high precision pickup of the hydraulic fracturing microseismic events is particularly urgent. In this paper, westart from the formation mechanism of microseismic, analyzed the current several kinds ofmicroseismic monitoring method and its microseismic signal characteristiscs. On the basis ofsummarizing and analysis of the current automatic pick up algorithm, thinking of themicroseismic events automatick pick up should be subdivided into microseismic events‘recognition’ and high precition ‘pick up’ two parts.The prior condition of the autoumatic identification and pick up algorithms is that themicroseismic source within a certain range and the difference of the primary wave time is notbig, implementation technology solutions can be summed up in five steps:(1) Artificialidentify microseismic data a significant landmark in the micro seismic events, and calculatethe first arrival wave time difference;(2)Accrording the time difference, we do staticcorrection for the entire data, and implement vertical stack form model way(stack);(3)Inorder to further highlight the target signal, we calculate the instantaneous energy of the stackby Hibert transform;(4) Based on energy threshold and the judgment standard, we completethe identify of microseismic events;(5)We get the travel time by do cross-correlation between stack and microseismic data in the time window which is determined by the formerrecognition results.Based on the research technical route, we program to realize the algorithm. We verify thecorrectness of the algorithm through the test of the forword mumerical simulation data whichis based on ray tracing. On the basis, we put the measured data into test, the results show thatthe algorithm has good effect and practicability. In addition, at the end of the article the analysisand summary of conventional processing methods and key points were given.
Keywords/Search Tags:Hydraulic fracturing, Microseismic mornitoring, Event indetify, Automatic pickup, Hilbert transform
PDF Full Text Request
Related items