The motion of drill strings is modeled in the drilling of geotechnological wells in the mining industry by the Lumped-Parameter Method (LPM). This method is widely used in structural mechanics and is most justified in modeling dynamic systems with a variable structure. On the example of horizontal drilling of geotechnological wells. longitudinal vibrations of a drill string with a sta... https://parisnaturalfoodes.shop/product-category/pro-collagen-m/