Approaches to prediction of the Ordovician weathering-crust reservoir in D66 well zone,Daniudi gas field

As the discoveries of high-yield gas flow in the Ordovician weathering crusts in wells such as D66-38 and D66-52 in D66 well zone,the Ordovician weathering-crust gas reservoirs have being accepted as an important supplementary gas source in Daniudi gas field.However,the exploration and exploitation of the Ordovician weathering-crust gas reservoirs are impeded by many factors,including variety of reservoir types(fracture,fissure,cave,and rug),lateral heterogeneity,thin reservoir,and low signal-to-noise ratio of seismic data.Adopting a general idea that based on geological knowledge,guided by well control,and using the object-oriented processed seismic data to distinguish favorable prospects through reservoir classification and geology-seismic comprehensive evaluation,we discussed the prediction and assessment of the Ordovician weathering-crust reservoirs.