Not consistently locatable? Do you think this is just oil fields catching fire? The burn offs are a conscious decision to burn off excess, made by the well operator. All you need to do to locate a burn off is to ask the well operator to tell you when they are burning.
And as far as scheduling: gas power isn't like wind or solar power. You don't need to schedule it. All you need to store gas is a big tank.
No, I have no reason to assume the need to burn off at any particular location at any particular time is consistently reliable (it may or may not be; I was a geographer, not a geologist). The decision to make the action may be conscious, but the timing of the implementation may be reactive to conditions either with a stochastic build-up, a pocket of gas being hit, or when the equipment is down for maintenance (the latter of which probably would be schedulable)
Even if it were schedulable and constitent in quantity, the catchment area is fairly wide and would require considerable infrastructure to gather, which the oil companies were not geared to do to begin with (they were going for petroleum, not methane). From what another local poster mentioned, there are plans in the works to capture some of that methane, but they require studies, licenses, etc. etc.
And as far as scheduling: gas power isn't like wind or solar power. You don't need to schedule it. All you need to store gas is a big tank.