The drilling will commence or stop regardless of the pipelines that are constructed. At the moment there is less oil flowing out thanks to OPEC, but should that change as some folks are thinking in a few years, that number is going to climb again. Perhaps more modestly than before, but it is still there.
What we are debating is much less whether one drills, but what to do with the product once it is collected. Rail and truck is incredibly dangerous. Given the state's roads were not devised for a boom of the sort that they had experienced over the past several years, and given the hazards of the often-harsh winters, pipeline is much more attractive. Train derailments or truck accidents are very serious affairs, being explosively fatal.
Pipelines meanwhile, pose their own risks, mainly in spills that damage the local environment or water quality. Clean-up is incredibly time consuming and expensive.
In many ways, when you are dealing with a state that doesn't have the infrastructure to handle vehicle traffic and accidents from rail, you are weighing human deaths and town decimation over environmental destruction. For this reason, pipelines are often preferred.
