The object of the study is a downhole assembly with a steered downhole diverting motor. While drilling deep oil and gas wells their profile should ensure minimum resistance forces to the drill string movement. One of the options is a profile with several sections of deviation angle setting by a large radius alternating with sections of stabilization. To increase the precision of the set radius realization there have been suggested the downhole assemblies providing a contact of supporting elements with the well walls at four points. At rotating such assembly in the deviated well a dynamic interaction of its elements with the wellbore wall might occur there. To prevent such situation it is necessary to create the appropriate gaps, which are designed using a special technique. The study performed enables to choose an assembly based the downhole diverting motor of diameter 172 mm with the angle of obliquity 1o, 1.25o and with drilling bits 215.9 and 220.7 mm to achieve the designed radius of the deviation angle setting within 400-800 m. The assemblies proposed can provide a maximally precise realization of the set well inclination radius without a dynamic interaction of its elements with the well walls. This will enable to reduce a number of operations in correction of the borehole trajectory and quality.
References
1. Povalikhin A.S., Kalinin A.G., Bastrikov S.N., Solodkiy K.M., Burenie naklonnykh, gorizontal’nykh i mnogozaboynykh skvazhin (Directional, horizontal and multihole drilling), Moscow: Publ. of TsentLitNefteGaz, 2011, 647 p.
2. Grechin E.G., Dolgushin V.V., Pyal'chenkov V.A. et al., Designing the downhole drill string assembly with motor-deflector with four-point pattern of its interaction with borehole walls (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2017, no. 9, pp. 82–85.
