“ How much time will it be over $30 before the shale producers start up again?” I work in this field, and the answer to your question is “instantaneously.” The largest operators will not go out of business because they have sufficient exposure to non-shale assets; they will simply immediately drill the wells they had planned to drill when the crisis hit. Capital will rapidly find its way into the hands of the people with the expertise to drill and complete money-making wells.

The oil industry is like one of those organisms that evolved to thrive in an intertidal zone, or in a region with random lengthy droughts. The industry knows how to shed or calcify all the parts of itself it doesn’t need in lean times and then rapidly redeploy those parts as soon as the environment changes, because this sort of thing happens over and over and over. Sometimes the thing the industry doesn’t need it and therefor sheds is “workers” and that’s a shame, but so it goes.

>That the idea of "put them out of business and then double the price" won't really work in a practical manner.

Well, then you haven't paid any attention because that isn't the strategy. The strategy is to force them to become members of the cartel or you risk taking losses every decade. Those losses aren't high enough to drive out competition but they are high enough to make cooperation appealing.

> How much time will it be over $30 before the shale producers start up again?

I think that depends on how expensive it is to "start up again." If it costs $10mil to turn the taps on, then it won't be economic to do so unless the operators expect oil prices to stay above the $30 level long enough to make up the startup cost in operating profit.

From that perspective, an oil cartel could keep unconventional oil out of the market by holding out a credible threat that they'll crash the prices if ever unconventional oil becomes too big.

I think it’s more a side-effect of the Russia pricing fight than the goal itself.

If the price drops and shale producers don’t have the capital to whether the storm then they don’t have much of a choice. Sure later they could come back when prices are high again, but in practice that’s probably hard and takes time.