Sequence Stratigraphy And Depositional Microfacies Through-going Research Of Integrating Well Logging And Seismic On The Close Spacing Distrcit

After more than forty years' development, most oil fields in Changyuan of Daqing Regionhave entered the stage of high water cut;the subsurface sand bodies have had the high degree ofreservoir recovery;and the distribution of oil and water has undergone the extreme change. Sothe main object of exploitation has turned into the thin-bed and highly dispersed oil layers fromthe thick.According to the research on the tectonic zone of Xing 56 district in Changyuan of DaqingRegion, integrating seismic data with geological and well logging data, on the basis of seismicdata processing of high fidelity, this project has used the theory of high resolution of sequencestratigraphy and seismic attribute to analyze the distribution of plane depositional facies and toforecast the interwell sand bodies.Based on the conventional geological research, this project is designed to use such keymethods as following: 1) the division and correlation of strata using the theory of high resolutionof sequence stratigraphy;2) the correlation of sand bodies on the basis of depositional facies;3)the extraction of 3-D seismic data attribute;4) mapping of plane depositional facies using welllog data and seismic data. These methods are independent while they can restrict each other. Andsuch methods above are the guiding ideology of this research..Using the theory of high resolution of sequence stratigraphy, this project has divided thesequence strata of interest, and integrated the micro-facies to correlate the sand bodies. To thedivision of the sequence, we focus on the control of sequence to sand bodies. In this paper, P1member is divided into four short-term sequences and twelve ultra-short-term. This projectestablished ten types of well logging facies modeling and to set up the modeling of thedistribution of depositional facies of typical reservoir profile. This paper has also set up the sevenkinds of relation of contract between sand bodies and six kinds of manners of connectivity ofchannel sand bodies.Using the 3-D seismic data, this paper makes use of the seismic attribute to map the planedepositional facies. We view composite sand bodies as short-term sequences and map dominatefacies on the basis of the sand content;and we also view single sand bodies as ultra short-termsequences and map the plane micro-facies on the basis of the sand thickness and verticaldepositional sequences. There are six kinds of seismic attributes extracted in this research, whichare correlated with the sand content. According to characteristics of this region, we interpolateone more point of seismic attribute among wells to make the former interwell spacing which are300 meters to be 150 meters and to control the distribution of plane depositional micro-facies.From the plane depositional facies, P1 layer is the deposition of fluvial dominate delta,which develop many distributary channels. So the images of the sedimentary environment aredescribed below: the delta depositions are mainly branched distributary channels which aremainly narrow and different in each layer;channel bodies grow in number towards downriver, ofwhich the scale becomes smaller;the distributary sand bodies become smaller and morescattered and the plane depositional facies change fast;the subfacies of delta front, when the lakewater is shallow, are mainly subaqueous distributary channels;and the sand sheet are welldeveloped and distal bar are developed.