Claudio Virues, a senior reservoir engineer with CNOOC Nexen, said frac hits have become a top concern in the shale business because they can affect several wells on a pad, along with those on nearby pads too.

He is alluding to the fact that some wells impacted by frac hits never fully recover and, in the worst cases, permanently stop producing after taking frac hits.

Leshchyshyn, president of the ­Calgary-based consultancy FracKnowledge, said that the Canadian government became involved in frac hits after they were blamed for a number of surface releases, mostly involving damage to low-­pressure wellheads and older vertical wells.

Shale producers are drilling new wells closer together, and closer to older wells, all in an effort to drain as much of the available reservoir area as possible.

Another idea is to recharge the offset wells using gas, either natural gas or carbon dioxide, neither of which should lead to well damage.

If gas compression facilities are available, operators could continuously pump natural gas into offset wells to increase their local pore pressure to ward off an oncoming fracture.

The caveat to this diagnosis method is that it has only been tested on shale gas wells because their single-phase flow is more reliably assessed with RTA compared with oil wells which involve more complex multiphase flow.