You might also note that the Germans formed a specialist unit (Oil Brigade Caucasus) with a strength of 10,704 men, including many specialists, 1142 vehicles, and 6 aircraft. This unit was held in reserve with AGS for the eventual use in repairing these oilfields.
The problem here is that this unit took a huge chunk of the available specialist engineering manpower, motor transport, and other equipment and put it essentially out of use by AGS at a time when the entire Group had only sufficent motor transport to supply a single army's advance. The typical infantry division at the time had virtually no motor vehicles as these were stripped to support the single Army advance. Such was the shortage of trucks in the Wehrmacht.
One more example of short-sightedness on the part of the Germans. In this case putting the cart before the horse.