1. A system for collaboratively managing oilfield operations for an oilfield having geological formations and reservoirs therein, comprising: a network; a workflow server connected to the network, the workflow server configured to execute a workflow manager, the workflow manager allowing a user to graphically define, edit, and automatically run a workflow for performing oilfield operations; and a plurality of user computers connected to the workflow server over the network, each user computer configured to allow a user to access the workflow manager and the workflow; wherein the workflow manager is configured to allow users to collaborate in defining, editing, and running the workflow.