We apply the classical field method to simulate the production of correlated atoms during the collision of two Bose-Einstein condensates. Our nonperturbative method includes the effect of quantum noise, and describes collisions of high density condensates with very large out-scattered fractions. Quantum correlation functions for the scattered atoms show that the correlation between pairs of atoms of opposite momentum is rather small. We also predict the existence of quantum turbulence in the field of the scattered atoms.