A Method for Directly Inverting Low Permeability “Sweet spot” by Using Elastic Impedance Equation

The "sweet spot" in low-permeability reservoirs is a very important geological target in the exploration and development of low-permeability oil and gas.It is of great significance to study the "sweet spot" prediction and identification methods for low-permeability reservoirs.Firstly, based on the definition of low-permeability "sweet plot", the sensitive elastic parameters of "sweet spot" are determined.On this basis, the elastic impedance inversion and "sweet spot" sensitive parameters prediction are proposed by the elastic impedance equation including the sensitive parameters of "sweet plot".This method reduces the cumulative error of indirect prediction of "sweet plot" and improves the accuracy of the "sweet plot" prediction.Combined with the Facies and fluids probabilities(FFP) technology, it achieves better results in the prediction of the "sweet plot" for the target area.