基于地震分频构型反演预测煤系致密砂岩薄储层OA

The thin reservoir of coal measure tight sandstone in Shenfu gas field in the eastern margin of Ordos Basin has the characteristics of low porosity,low permeability,strong heterogeneity and thin single sand body.Conventional prediction methods are difficult to meet the needs of fine characterization,which restricts the exploration and development of coal measure tight sandstone gas in this area.Therefore,combined with the'facies-controlled-logging-seismic'data,the reconstruction curves sensitive to lithology and fluid are integrated into the frequency-division configuration inversion to form a set of technical system suitable for the prediction of thin reservoirs in tight sandstone of coal measures in the eastern margin of Ordos Basin,and applied to the practical verification of the study area.The results show that:(1)The reconstructed pseudo-wave impedance curve can effectively indicate the gas-bearing reservoir,which provides a reliable parameter basis for subsequent configuration inversion.(2)The seismic inversion technology of frequency division configuration is controlled by facies,and the information of low(0-10 Hz),medium(10-100 Hz),high(100-200 Hz)and ultra-high(>200 Hz)frequency bands is fused,which significantly improves the prediction accuracy of seismic inversion for thin sandstone reservoirs in coal measures.(3)After verification of multiple wells that did not participate in seismic configuration inversion,the seismic inversion results were in agreement with the drilling results by 80%.Based on the prediction results,nine new wells were deployed,and the thickness of the drilled gas layer was 1.3-12.3 m,with a coincidence rate of 89%.It is concluded that the established comprehensive prediction technology system overcomes the technical bottleneck of thin reservoir prediction of coal measure tight sandstone in the eastern margin of Ordos Basin,and verifies its engineering practicability,which can provide reference for the exploration and development of coal measure tight sandstone reservoirs with other similar geological conditions.