This could be the beginning of the end of the US shale oil boom.The chart below, from SCLinx’s managing partner for energy, Gary Flaharty, shows the oil rig count is falling off a cliff — it’s at 922 at last Friday’s Baker Hughes count, down from a high of over 1600 at the beginning of the year — in exactly the same way that the natural gas rig count fell off at the end of the shale gas boom a couple of years ago.The current shale oil boom is in the green box, and the recent shale gas boom is in the red box.This doesn’t mean that production is going to fall; despite lower rig counts, the new wells being drilled have been very effcient and they pump oil for a long time.But this does mean that the astonishing growth of production the US has seen in the last few years is certainly stabilizing.That has plenty of implications for the industry, from investment to employment. The industry might even be starting to think about what’s next.Here’s what happened with the gas boom, from Flaharty: Production from the unconventional gas plays more than satisfied the US markets and in September 2008 market sentiment collapsed. The gas-directed rig count, shown in Chart 2, peaked at 1,606. Lower gas prices would not support dry gas development, and attention shifted to wetter plays where oil and natural gas liquids NGLs production could drive acceptable economic returns. Oil and gas companies pivoted, if they could, away from dry gas and towards oil and NGL plays. The gas-directed rig count fell precipitously. Despite a significantly lower gas-directed rig count, shale-gas production rose and has continued to rise since, despite a declining rig count. More efficient drilling techniques, an increase in the number of wells drilled per rig, attractive economic returns on wet gas NGLs wells, and more production per well have more than offset the production decline from the existing conventional well population.Read Flaharty’s whole post at OilPro.