Production in the USA. How long will it take to decline by half if there is no new drilling?

1.3 million individual well production forecasts are aggregated to estimate the time it will take for production to decline by half in the USA if no new wells are drilled. Drilling is currently less than a third of its 2014 levels. Considerable capital is required to replace declining production, capital which might not be readily available. Half production for the USA is forecast to be hit before 2022. For the shale basins such as the Bakken and Eagle Ford, it will be in the next 1 - 3 years. This means that hundreds of thousands of new wells will have to be drilled to restore production to 2014 levels. The limiting factor in exploiting American shale reserves may be access to capital, not geology.