A High Court appeal to stop the fracking was unsuccessful on Friday.
The work marks the first time fracking has taken place in the UK since 2011, when the process was halted after it caused two small earthquakes in Lancashire.
Police closed off the site earlier as around 50 protesters gathered before the work began.
A team had to cut a man and woman out of a set of tyres which they had apparently cemented their arms into.
One activist sat on top of a van outside the site with a banner reading "Stop the Start", while another laid down in front of railings.
SKY News.
