My brother just retired from Schlumberger and spent nearly 30 years with them. You're right, they've been doing it for quite a while and quite well, but others have not. Those others, human error and explosion of drilling will absolutely lead to more issues. Issues that simply can't have a price put on.
He has very specifically told me that while we are both making great money off the gobs of Schlumberger stock we've purchased and had provided over the years, keep it at that. If they drill anywhere near your land, move. Period. I trust and fully believe him. It's just simple fact that the shit they are doing is very risky and many of those risks and issues that have occurred are quickly buried with money.
We've all been around long enough to know when you mix, shit tons of money, mention gas or oil, companies like Halliburton are involved and politicians and regulations are involved and the processes here bring words like toxicity, cancer, radiation and well water contamination ......all that mixed into one sentence will equal a chance in hell if it were to freeze over of any truth coming out. Run.