Patent ID: 6418630
Filing Date: 2002-07-16
Classification: G06G

Abstract:
Deviation calculation rule of the circular type for monitoring a two-dimensional deviated well path, characterized by the fact that it comprises:a support plate (10) on which is marked a fixed circular dial used to locate or index the inclination angle (i1) at the point of entry (E) of the section of the path and the inclination angle (i2) at the exit point (S) of said section, where said fixed dial consists of two semi-circular scales (G1, G2) each graduated counter clockwise from 0 to 180Â°, where the first (G1) represents the area of increase of the inclination (i12) and the second (G2) represents the area of decrease of the inclination (i1>i2); at least two interchangeable rotary disks (12, 121) for indexing the entry inclination, choosing or locating the â€œbuild-upâ€  gradient value and choosing or reading the drilled length over the desired interval, where the diameter of said rotary disks is slightly less than that of the circular dial and the disks are stacked on the support plate (10), concentrically to the dial, so that only the disk that is placed on top is active and the other waits to be used, where said rotary disks have a plurality of concentric circles (C1 through Cn; Câ€²1, through Câ€²n) each corresponding to an inclination gradient per given drilled length (Gbu), so that all the disks cover all the values of the gradients commonly encountered in practice, where each disk is divided by a diametral line (L) used to locate and index the entry inclination value of said section on the circular dial scales and demarcate on each of said concentric circles, a first semi-circular scale (F1) graduated counter clockwise in drilled lengths and making it possible to work in the area of increases of inclination and a second semi-circular scale (F2) graduated m the same way but clockwise and making it possible to work in the area of deceases of the inclination, where the zero graduations of these two semi-circular scales coincide; at least one bi-sectoral rotary disk (14) for reading or indexing an exit inclination, locating the value of the â€œbuild-upâ€  gradient and managing path calculations linked to straight sections, where said bi-sectoral disk has the shape of two circular sectors (141, 142) diametrically opposite at their top and with a radius that is less than that of the circular dial and arranged above the rotary disks, concentrically to the latter, where one (141) of the sectors of the bi-sectoral disks has a first graduated scale (E1) used to locate the Gbu circles (Câ€²1 through Câ€²n) of the rotary disk (121) on one of its radial edges, and a second scale (E2) used to locate the Gbu circles (C1 through Cn) of the other rotary disk (12) on its other radial edge, where said scales coincide symmetrically (at E4, E3 respectively) on the radial edges of the other sector (142), and said bi-sectoral disk also has a diametral line (L1) on which are marked on each of its sides two scales (F3, F4) graduated, top to tail, in drilled lengths and used to deal with problems linked to straight sections, where said bi-sectoral disk as well as the rotary disks can be rotated independently of each other, around a link component (50) such as an axis, that passes through their center and also passes through the support plate at the center of the circular dial, and adjustable sliding means (16h, 16v; 100, 110) that allow for a simple reading or pre-selection of the deflection deviation or the vertical depth deviation at a given value, so as to determine the Gbu circle that corresponds to this deviation and read the drilled length on this circle.