DETERMINATION OF THE CONDITIONS FOR THE IMPLEMENTATION OF THE DEFORMED DRILLING LAYOUT ROTATION IN THE MODE OF STABILIZATION OF THE BOREHOLE DIRECTION

Link for citation: Buglov N.A., Pushmin P.S. Determination of the conditions for the implementation of the deformed drilling layout rotation in the mode of stabilization of the borehole direction. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 7, рр.17-25.In Rus. The relevance of the study is caused by the need to create a general methodology for determining the eccentricity of the inertia center of the core set cross-section, which will significantly reduce the irrational material and energy costs of drilling wells drilled in conditions of natural curvature of their trunks, as well as optimize the technical and economic indicators of drilling operations. Objective: to increase the productivity of geological exploration when working in conditions of natural curvature of boreholes. Objects: drilling well, column set, drilling shell, drill string, natural curvature of the borehole, the trajectory of the borehole. Methods: analysis of literature sources on the research topic; processing data of production organizations; graphoanalytic method. Results. To eliminate some of the shortcomings currently available in the issue of maintaining the trajectory of the borehole drilled in conditions of natural curvature, a general technique is proposed that ensures minimization of the deflecting force on the rock-breaking tool during the deepening. The proposed technique is divided into two components: the use of pre-deformed core sets; the creation of a direct precession with continuous contact of the half-wave crest with the well wall during rotation of the arrangement. To implement the first case, the paper presents a method for determining the value of residual or preliminary deformation of a rectilinear core pipe. Practically, the proposed technique is implemented by sequentially performing three basic operations: the plane of deformation of the core set is determined during drilling; the parameters of the core set are adjusted by its residual deformation by the calculated value; the well is drilled with a pre-deformed core set. To implement the second case, the paper presents a method for determining the magnitude of the eccentricity of the inertia center of the column set cross-section. In this case, in order to implement the method, it is necessary: to make a rational arrangement of the lower part of the drill string; to carry out the drilling process at the maximum possible rotation frequencies of the drill shaft; to use emulsion washing fluids; to reduce the amount of bending moment due to the operation of diamond crowns that work effectively at low axial forces. Both proposed methods are justified and supported by the results of experimental work. Conclusions. The conducted research allowed us to present and justify a fundamentally new method of reducing the curvature of boreholes based on the use of pre-deformed core sets, as well as to obtain a dependence for determining the optimal value of their residual initial bending, which guarantees a deflection force close to zero on a rock-breaking tool. The magnitude of the eccentricity of the stabilizing arrangement, which guarantees the operation of the guide section in the mode of direct precession: is directly proportional to the force of its interaction with the walls of the well; is inversely proportional to its mass and rotational speed; is directly proportional to the coefficient of sliding friction.