Seismic response characteristics and identification methods of turbidite reservoir in limestone background:A case study of Well Tuo71 Area in Dongying Sag
The turbidite reservoirs in Dongying Sag in limestone background mainly exist in forms of thin beds or thin interbeds. It is difficult to identify them on seismic section because there is little difference in wave impedance between limy mudstone and turbidite reservoir. Thus a method combining numerical simulation of post-stack elastic wave equation and prestack seismic inversion is proposed. In order to eliminate the interference of limy mudstone and take full usage of elastic information of prestack seismic inversion,on the basis of logging-constrained prestack inversion,a sensitivity factor R is introduced to quantitatively evaluate the lithological sensitivity,and considering multi-elastic lithological information fusion,a mathematical model is constructed to optimize elastic parameters that sensitive to limy mudstone and turbidite. Meanwhile,combined with the numerical simulation of poststack elastic wave equation,the identification methods of thick turbidite and thin interbedded turbidite reservoirs in limestone background are studied to achieve the purpose of reservoir optimization. For turbidite reservoirs in limestone background in Well Tuo71 Area,Dongying Sag,combining multi-elastic lithological information fusion with the numerical simulation of elastic wave equation,an effective identification method of turbidite and thin interbeds of turbidite in limestone background is proposed,which is important to guide the reservoir identification and optimization.