Method for optimising drilling parameters

The method comprises obtaining previously acquired data, e.g. data for another well drilled in the same general area, querying a remote data store for data relating to the well for which the parameters are to be optimised, determining optimised drilling parameters for a next drilling segment following the segment currently being drilled, and returning the optimised drilling parameters for the next drilling segment to the remote data store. The optimised drilling parameters are preferably used to control drilling, the data for the current well being correlated with the previously acquired data. The optimisation and correlation are preferably carried out with the use of trained artificial neural networks.