Time-Lapse Inversion Of Velocity And Q Factor And Geologic Applications

Reservoir is an important place for oil and gas accumulation,and it is also the key object in the research of oil and gas exploration and exploitation.Most Chinese oil fields are continental facies clastic rock reservoir with complex structure,strong heterogeneity.In the later development stage,although the remaining oil and gas are much,the recovery rate is low,so reservoir monitoring is required higher,in order to better understand the displacement mode of fluid in reservoir,explore the remaining oil,help develop mining scheme,extend the economic life of oil and gas fields.The thesis apply velocity and Q factor into time-lapse seismic inversion.We carry out traveltime tomography and attenuation tomography to get low frequency macro-velocity and –Q factor model,complement time-lapse tomography to highlight reservoir change only due to production to get base and monitor coupling macro-Q factor model,following by computing instantaneous frequency and pre-stack migration for obtaining high frequency micro-model.Then we obtain broadband Q model by merging the macro-and micro-model to improve the image resolution,realizes the purpose of delineating structure boundary,thin layer and monitoring reservoir.The thesis applies the method into real seismic data in S area for delineating thin layer,structure boundary and detecting oil.Compared with normal seismic section,velocity and Q factor seismic section is able to improve resolution and delineate thin layer with 15 m depth,small anticline with 30 m high relief and detect the existence of oil.The real production data in S area proves that the correction of the method we proposed.