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The result of construction of the underwater crossing by the method of horizontal directional drilling is the pipeline laid in a well. For successful scrubbing of the pipeline it is necessary to prepare well which design parameters will ensure smooth passage of the pipeline. The study of the results of scrubbing main pipelines in the construction of underwater transitions shows that the emergence of technological complications with the well areas, which are characterized by the presence of: ledges (steps) in Transition intervals of soils differing in strength; Intervals of collapse of uncemented soils and unstable clay soils; areas where large-scale inclusions are accumulated. In order to prevent technological complications and avoid the loss of the constructed underwater transition with the pipeline in it due to the presence of zones of complicated intervals in the built well it is necessary to present strict requirements as to the condition of the borehole the underwater transition of the pipeline, and control its geometrical parameters and profile before the dragging of the pipeline. Therefore, the well-known results of laying of pipelines at transitions constructed by the method of inclined directional drilling were studied, their interrelation with possible change of a trajectory of a pipeline in a well at presence of obstacles on well. Attention was drawn to the mutual influence of the traction forces of the drilling rig and the elastic-deformative and strength characteristics of the pipeline. As a result of the work carried out the conditions necessary for safe scrubbing of the pipeline in the well of the underwater transition when changing the trajectory of the pipeline in the well due to the presence of a zone of soil accumulation. References 1. Sharafutdinov Z.Z., Parizher V.I., Sorokin D.N. et al., Stroitel'stvo perekhodov magistral'nykh truboprovodov cherez estestvennye i iskusstvennye prepyatstviya (Construction of crossings of trunk pipelines through natural and artificial obstacles), Novosibirsk: Nauka Publ., 2013, 339 p. 2. Sharafutdinov Z.Z., Sapsay A.N., Shatalov D.A. et al., Engineering and technical issues of pulling a pipeline through a well of an submerged crossing (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2018, no. 10, pp. 114–119. 3. Sapsay A.N., Sharafutdinov Z.Z., Urmancheev S.F., Determination of optimal hole curvature for construction of underwater crossing (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2019, no. 2, pp. 90–93. 4. Sapsay A.N., Sharafutdinov Z.Z., Urmancheev S.F., Durability of the drill string during the construction of pipeline underwater crossings by the directional drilling method (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2018, no. 5, pp. 88–92. 5. Vafin D.R., Komarov A.I., Shatalov D.A., Sharafutdinov Z.Z., Geomechanical modeling of building conditions for main pipeline submerged crossings (In Russ.), Nauka i tehnologii truboprovodnogo transporta nefti i nefteproduktov = Science & Technologies: Oil and Oil Products Pipeline Transportation, 2016, no. 4(24), pp. 54–64. |
