Development of construction and analysis of the elastic shells packet stability of the device for well trajectory management

Abstract

Overview of equipment for management of a trajectory of directional and horizontal wells during drill process was done in the article. Both domestic and foreign equipment are described. Based on the critical analyses, most promising designs were chosen and were described their base disadvantage: restriction of range of changing of curvature angle of deflecting tool through some design features. Based on mentioned above, modern device for management of directional and horizontal wells trajectory was suggested. Advanced unit for curvature of deflecting tool’s axle is fundamentals of construction. Using of the elastic shells packet that loses stability by critical axial load and gets small longitudinal deformation is the main innovation. Further, it is a reason of unlocking the mutual movement of specific elements of the device and buckling of its axis on preset angle. That’s why angle of deflecting tool curvature does not depend of absolute longitudinal deformation of the elastic shells packet and, as result, is not restricted by them. Deflecting tool’s axis gets the rectilinear shape after a drill string is torn off from a downhole. So, there is possible to manage a well axis during drilling process using stretching and compression of the deflecting tool. The elastic shells packet that consists of variable quantity of shells is used for setting necessary compression force that switches device in regime of curvature. Stability of the packet was analyzed by 3D-modeling and finite element method. The magnitude of critical force is determined depending on the number of shells in the packet. Was mentioned, this dependence is rectilinear. There is a possibility, by selecting the number of shells in the elastic shells packet, to manage magnitude of axial compression force that causes bend of the deflecting tool’s axis considering needed bit load.