Research And Implementation Of Single Well Reflected Acoustic Logging Data Processing Method

Reflection acoustic logging and data processing is a new technology of geophysical in recent years.It's mainly used for exploration and development of oil and natural gas.It can detect the geological reflectors such as cracks,faults or layer interface which is a few meters or tens of meters next to the well.It has a wide application prospect.In this paper,we use the existing array acoustic logging data to extract the reflected acoustic signal effectively and to do the reflected wave imaging by means of signal processing.In the past thirty years,a large number of array acoustic logging data have been accumulated in domestic oil fields.The mining and utilization of reflected wave information in the exploration and development of oil fields can save a great deal of manpower and material cost.The main problem is that the reflected wave signal in the array acoustic logging data is weak,and it is more serious with the mode wave(stratigraphic wave,formation shear wave,Stone wave and pseudo Rayleigh wave),which makes the reflected wave signal difficult to identify and extract.First,the monopole array acoustic logging data,the reflected wave signal processing,and a series of processing methods in reflected wave imaging technology,such as preprocessing,reflection wave enhancement,migration imaging and so on,have been systematically investigated,and some effective processing methods are realized,and the validity of the relevant methods is verified by numerical simulation.Among them,median filtering,F-K filtering and ?-p transformation are realized in the extraction of reflected wave and upgoing and downgoing wave.In the enhancement processing of reflected wave,the algorithm of dynamic correction and superposition is realized.In the reflected wave migration imaging,the algorithm of F-K migration,Kirchhoff migration and diffraction scan superposition migration is realized.In addition,for the dipole acoustic logging data,pressure vibration and determine the azimuth of the reflection interface are realized,which can also effectively deal with the dipole acoustic data.Then,this paper has formed a set of effective processes by implementing these methods,and develop a systematic and practical software.The software is mainly written in Qt language.It can handle the monopole and dipole array acoustic data.It mainly includes four modules: preprocessing,wave field separation,reflection wave enhancement and reflection wave migration imaging,which can be processed artificially and the results of processing have been displayed graphically.Multi-thread technology is applied to migration imaging,which greatly improves computationefficiency.Finally,the array acoustic logging data of two wells in the oilfield were processed with the developed software.It is found that the effect of F-K filtering is better in the extraction of the reflected wave signal and the separation of the upgoing and downgoing waves.In the reflected wave imaging,the effect of the Kirchhoff migration is better,and the efficiency of the F-K migration and diffraction scan superposition migration is higher.The result of the reflection processing in one well is compared with those in foreign commercial logging software,and the results agree with each other.The data processing results show that the processing method and the software developed in this paper can meet the needs the reflection acoustic imaging processing of the existing array sonic logging data and geological application.