Structural Interpretation And Reservoir Prediction Of Ng8-10 In The West Distract Of Chengdong Oilfield

Chengdong oilfield is located on Chengzikou uplift in Zhanhua sag.In the south direction it is bounded by Chengnan Fault,adjacent to Zhanhua Sag,and in the north direction is neighbored by Chengbei Sag.The Chengdong oilfield is divided into east distract and west distract by Cheng21 fault.The study area is located in the west distract of Chengdong oilfield.With the increase of exploration and development of the oilfield,the main reservoirs in the study area have entered into the stage of extra high water cut development.The Ng8-10 sand groups in the west distract of Chengdong Oilfield are a set of braided stream deposits,which are not the main oil-bearing layers of Chengdong Oilfield.But it is an important oil-bearing layer series.Although it has the characteristics of overlapping sand bodies and large thickness,the location of the main channels and the distribution of sand bodies are not clear,which brings difficulties for further development and increasing production.Moreover,the development law of small faults,which were formed during the sedimentary period of the 10th sand group in the lower member of Guantao formation,is also not clear.In this paper,the Ng8-10 sand groups in the lower member Guantao formation are taken as the research object,and the layers and faults in the study area are interpreted in detail by using synthetic record calibration,variance volume technique,coherence volume technique and curvature property of dimension combined with conventional section interpretation.On the basis of well-seismic correlation,the subdivision and correlation of Ng8-10 sand groups in the lower member Guantao formation of west distract of Chengdong Oilfield are completed by comparing the skeleton sections of the study area and the closure of the whole area.The fine stratigraphic framework is established.The distribution characteristics of sand bodies are analyzed by using stratal slicing technique and seismic attribute analysis in combination with logging data.During the development periods of Ng9 and Ng10 sand groups,a large supply of sediments were deposited around.The average thicknesses of 10~1 and 9~3 layers are all over 10 meters,and the distribution ranges are large.During the sedimentary period of Ng8 sand group,with the change of sedimentary environment,the supply of sediment was decreased.The thickness of sand bodies and the distribution range both are smaller.Combining with the related research results of logging interpretation,two favorable sand bodies are predicted.