Qingfeng (Tommy) Kong, Deling Lv, and Songhui Lin
Geophysical Research Institute of Shengli Oilfield, SINOPEC, Houston, TX
Most of oilfields in China are located in continental sediment basins. Compared with oil fields in marine basins, they have much more complex fault systems, small scale sand bodies, poorer sand connectivity, greater variation in facies and heterogeneity, therefore more difficulties in finding the remaining oil reserve. Conventional 3D surface seismic data, one of the best methods for reservoir characterization at the beginning of petroleum exploration, is efficient for bigger traps and structures while its vertical resolution is not high enough to meet the needs of reservoir characterization for petroleum production in these continental sediment basins. This study focuses on resolution improvement of 3D seismic data using borehole seismic data. Firstly, Q-value is directly computed from zero-offset VSP and shot gathers are filtered by modified inverse-Q operator. Secondly, the deconvolution operator derived from zero-offset VSP with higher vertical resolution is applied to the post-stack section. Thirdly, under the control of modified Cauchy distribution, impedance inversion is done by adding the constraint of cross-well seismic data. Finally, the fine description of thin layer can be completely achieved. Test results in one oilfield in Eastern China show that it has improved the vertical resolution from 6-7m to 3-5m in thickness. The work flow for seismic resolution improvement done by this study therefore has supplied reliable aids to reservoir characterization, remaining oil finding and well design planning in the tested field.
AAPG Search and Discovery Article #90152©2012 AAPG Southwest Section Meeting, Fort Worth, Texas, 19-22 May 2012