Development of technologies and tools for drilling additional wells from artificial bottom-hole with whipstock of continuous action in hard and very hard rocks

Background. Various approaches are currently used to create borehole curvature depending on associated methodological and practical geological problems. Continuous action whipstockes are considered to be the most modern and accurate among these approaches. The efficiency of such devices may decrease under difficult mining and geological conditions.

Aim. To increase the efficiency of drilling a curved borehole in hard and very hard rocks by reducing the speed of drilling out an artificial bottom.

Materials and methods. We studied the operating principles of various types of continuous action whipstocks. Empirical results were determined by studying the operation of continuous milling whipstocks in difficult rock conditions and by studying the materials used for manufacturing artificial bottom holes. The study included optimization of the efficiency of drilling a well in hard rocks from an artificial bottom hole in a new direction.

Results. The main factors decreasing the whipstock efficiency were found to be the mechanism of buildup rate, and the different strength of the rock and artificial bottom-hole. A feature of the work of a milling type whipstocks is that the creation of a deflecting force is carried out due to the constant influence of the axial load, the value of which proportionally affects the speed of drilling. A review of the materials used to create an artificial bottom led to the conclusion that at present there are no curable materials that would have a hardness higher than category 8 for drillability, which means that when trying to drill a new direction of a well in rocks more than 8 grade for drillability, the speed drilling with a continuous action whipstocks will exceed the optimum and reduce the intensity of the buildup rate whipstock.

Conclusion. Since the rate of drilling an artificial bottom hole is difficult to regulate using the drilling mode parameters, it is necessary to develop technical solutions that would limit the rate of deepening a new direction of the wellbore.

1. Vasiliev S.I., Miloserdov E.E., Tryapichkin M.A. Technological Techniques for Drilling Additional Directions from Artificial Bottoms in Open Holes. Mining. 2016. No. 4 (128). P. 73—76.

2. Kalinin A.G., Nikitin B.A., Solodkiy K.M., Sultanov B.Z. Drilling of inclined and horizontal wells: Handbook. Ed. A.G. Kalinin. Moscow: Nedra, 1997. 648 р.

3. Melnichuk I.P., Danilin A.K., Minashkin V.G. Method for creating direction in the well. Author’s certificate 956728; declared 10/28/1980; published 09/07/1982. 3 p.

4. Neskoromnykh V.V. Directional drilling and core measurement. Moscow: INFRA-M, 2015. 337 p.

5. Neskoromnykh V.V., Eliseev A.D., Grinchuk A.V., Nadelyaev A.A. Improving the technology for drilling additional wellbores in hard and very hard rocks with continuous rejects // Bulletin of the Siberian Branch of the Earth Sciences Section of the Russian Academy of Natural Sciences. Geology, prospecting and exploration of ore deposits. 2009. Vol. 34, No. 1. P. 154—159.

6. Neskoromnykh, V.V. Methods and technical means of wedge-free drilling of additional wellbores from artificial faces. Moscow: MGP Geoinformmark, 1993. 55 p.

7. Neskoromnykh V.V. Drilling of inclined, horizontal and multilateral wells. Krasnoyarsk: SFU, 2016. 320 р.

8. Shrago L.G., Yudborovsky I.M. Curvature of wells under the action of a constant magnitude of the deflecting force // Technique and technique of exploration. Leningrad, 1964. Issue 48. P. 47—51.

9. Morenov V., Leusheva E. Development of drilling mud solution for drilling in hard rocks // International journal of engineering, transactions a: basics. Materials and Energy Research Center. 2017. Vol. 30, No. 4. P. 620—626.

10. Tianshou Ma, Ping Chen, Jian Zhao. Overview on vertical and directional drilling technologies for the exploration and exploitation of deep petroleum resources. Geomechanics and Geophysics for Geo-Energy and Geo-Resources. 2016. Vol. 2, No. 4. P. 365—395.

11. Weiliang Wang, Yanfeng Geng, Ning Wang, Xiaojiao Pu. Joice de Oliveira Fiaux. Toolface Control Method for a Dynamic Point-the-Bit Rotary Steerable Drilling System. Energies. 2019. No 12. 1831 p.