The Study On Seismic Reservoir Prediction In The Lower Nm Formation Of KL10-1 Oilfield

The Laizhou Bay Depression is located in the southern Bohai Bay,and the regional tectonic position is located in the east of Jiyang Depression,Bohai Bay Basin,an area of about 1780km2.Kenli 10-1 oilfield is located in the North Zone of the north slope of Laizhou sag Bay,an area of about 200km2.The lithology of the lower Nm formation is mainly sand interbeded with mud in different thickness,which developed a series of fluival and delta deposits.Based on the theory of seismic reservoir prediction,this paper made a seismic prediction of Nm formation in KL10-1 oil field with the method of seismic forward modeling and seismic attributes analysis,with the application of geological,seismic and well data comprehensively.The purpose of the paper is to carry out the reservoir prediction research,predict the lateral distribution of sand bodies,provide the geological support for the development of the oil field,and guide the development of well pattern deployment.In reference to previous research and geological drilling technology,the paper firstly carried out the seismic forward modeling.According to the study of the river sand scale and its contact relationship,the paper made the sand body model.And on the analysis of the the reservoir petrophysical parameter,the paper give the velocity and the density of the sand and shale,then conduct the forward modeling with different wavelet frequency by using the ray tracing method.After analysis,the paper believed that only when the excitation frequency is greater than 40 HZ that the seismic data can reflect the reservoir sand effectively.Based on this research,the paper made simple geological model to study the lateral and vertical resolution of the raw seismic data for the channel.Secondly,because of the low sensitivity of the raw seismic data to the thin sand body,the paper used the seismic spectrum analysis to decompose the original seismic data into three types: high frequency,medium frequency and low frequency to extract the attribute.Combined with the forward modeling analysis,the paper selected 40 HZ seismic data to extract the seismic attributes.The paper used bedding slice to extract 15 kinds of seismic attributes.Analysis the physical meaning of the attributes and its correlation,the paper choose the root mean square attribute and sweetness attribute to make the reservoir prediction.Based on the analysis the correlation between the optimized attributes and the well sand thickness,the paper explain the sand characteristics,and then measure 3 morphometric,which including channel width,meander-bent width and meaner length.Based on the semi-quantitative analysis,the paper got the final sandstone thickness map and the sand ratio map after the correction with the well sand.