Abstract: We propose a method to invert two parameters(virgin zone resistivity,invaded zone) of dual lateral logging which is based on Newton-SVD of particle swarm.Reasonable initial values are selected by random particle swarm method.Newton-SVD is applied to invert dual lateral logging data.It improves stability and reliability of logging inversion greatly,and offers a radical way for setting initial values of inversion.Ideal model with noise and practical logging data are compared.It shows that the method eliminates effects of complex logging environments effectively and offer true formation parameters.

Key words: Newton-SVD based on stochastic particle swarm optimization, virgin zone resistivity, invaded zone, inversion