The article is devoted to the mathematical modeling of technological operations with coiled tubing (CT) and software development for the CT operations design, execution and quality control. The purpose of coiled tubing technology and types of technological operations that are performed in the well using coiled tubing are considered. Examples of application of software for modeling operations with coiled tubing – a СТ simulator are considered. The basic physical phenomena that must be taken into account for the correct CT modeling are described. A general description of the mathematical models and submodels that make up the CT simulator is given: forces calculation, CT stability loss types and criteria, the effect of hydraulics on the CT stress state, CT critical stress criteria, multiphase hydraulics, solids transport, fatigue failure. The description of the basic principles used in the development of the domestic CT simulator is given: a unified user interface for input data and displaying calculation results, performing a standard CT simulation in one run, an extensive database of CT, pipes, CT surface and bottom hole assembly, liquids, gases. The capabilities of a special software application for the data acquiring, processing and visualization in the coiled tubing / hydraulic fracturing fleets control station are described: the ability to display any graphs and scales on any number of windows and in any configuration: adaptive selection of graph sizes, scales and indicators, flexible adjustment of parameters for parsing the input data stream, which allows to adapt to any format of the text protocol; unlimited number of input channels; the ability to create calculated data channels.
At present, the corporate coiled tubing simulator and the data acquiring, processing and visualization software are being tested by the internal fracturing and coiled tubing service at the fields of Rosneft’s production units.
References
1. Ho H.-S., An improved modeling program for computing the torque and drag in directional and deep wells, SPE- 18047-MS, 1988, doi:10.2118/18047-MS.
2. Johancsik C.A., Friesen D.B., Dawson R., Torque and drag in directional wells-prediction and measurement, SPE-18047-MS, 1984, doi:10.2118/11380-PA.
3. Sheppard M.C., Wick C., Burgess T., Designing well paths to reduce drag and torque,SPE-15463-PA, 1987, doi:10.2118/15463-PA.
4. Mitchell R.F., Samuel R., How good is the torque/drag model, SPE-105068-PA, 2009, doi:10.2118/105068-PA.
5. Mirhaj S.A., Kaarstad E., Aadnoy B.S., Torque and drag modeling; soft-string versus stiff-string models, SPE-178197-MS, 2016, doi:10.2118/178197-MS.
6. Newman K.R., Finite element analysis of coiled tubing forces, SPE-89502-MS, 2004, doi:10.2118/89502-MS.
7. Newman K., Bhalla K., McSpadden A., Basic tubing forces model (TFM) calculation, Tech Note CTES, Texas, 2003.
8. Wu J., Juvkam-Wold H. C., Coiled tubing buckling implication in drilling and completing horizontal wells, SPE-26336-PA, 1995, doi:10.2118/26336-PA.
9. Feodos'ev V.I., Soprotivlenie materialov (Strength of materials), Moscow: Publ. of MSTU named after N.E.Bauman, 1999, 592 p.
10. Bhalla K., Walton I.C., The effect of fluid flow on coiled tubing reach,
SPE-36464-PA, 1998, doi:10.2118/36464-PA.
11. Kaya A.S., Comprehensive mechanistic modeling of two-phase flow in deviated wells, Oklahoma: The University of Tulsa, 1998, 93 p.
12. Caetano E.F., Upward vertical two-phase flow through an annulus: PhD dissertation, Oklahoma: The University of Tulsa, 1985.
13. Beggs H.D., Brill J.P., A study of two-phase flow in inclined pipes, JPT, 1973, May, pp. 607–617.
14. Zhang H.-Q., Wang Q., Sarica S., Bril J.P., Unified model for gas-liquid pipe flow via slug dynamics. Part 1: Model development, J. Energy Res. Technol., 2003, no. 125.
15. Avakov V.A., Foster J.C., Smith E.J., Coiled tubing life prediction, OTC-7325-MS, 1993, pp. 627–634.

The article is devoted to the mathematical modeling of technological operations with coiled tubing (CT) and software development for the CT operations design, execution and quality control. The purpose of coiled tubing technology and types of technological operations that are performed in the well using coiled tubing are considered. Examples of application of software for modeling operations with coiled tubing – a СТ simulator are considered. The basic physical phenomena that must be taken into account for the correct CT modeling are described. A general description of the mathematical models and submodels that make up the CT simulator is given: forces calculation, CT stability loss types and criteria, the effect of hydraulics on the CT stress state, CT critical stress criteria, multiphase hydraulics, solids transport, fatigue failure. The description of the basic principles used in the development of the domestic CT simulator is given: a unified user interface for input data and displaying calculation results, performing a standard CT simulation in one run, an extensive database of CT, pipes, CT surface and bottom hole assembly, liquids, gases. The capabilities of a special software application for the data acquiring, processing and visualization in the coiled tubing / hydraulic fracturing fleets control station are described: the ability to display any graphs and scales on any number of windows and in any configuration: adaptive selection of graph sizes, scales and indicators, flexible adjustment of parameters for parsing the input data stream, which allows to adapt to any format of the text protocol; unlimited number of input channels; the ability to create calculated data channels.
At present, the corporate coiled tubing simulator and the data acquiring, processing and visualization software are being tested by the internal fracturing and coiled tubing service at the fields of Rosneft’s production units.
References
1. Ho H.-S., An improved modeling program for computing the torque and drag in directional and deep wells, SPE- 18047-MS, 1988, doi:10.2118/18047-MS.
2. Johancsik C.A., Friesen D.B., Dawson R., Torque and drag in directional wells-prediction and measurement, SPE-18047-MS, 1984, doi:10.2118/11380-PA.
3. Sheppard M.C., Wick C., Burgess T., Designing well paths to reduce drag and torque,SPE-15463-PA, 1987, doi:10.2118/15463-PA.
4. Mitchell R.F., Samuel R., How good is the torque/drag model, SPE-105068-PA, 2009, doi:10.2118/105068-PA.
5. Mirhaj S.A., Kaarstad E., Aadnoy B.S., Torque and drag modeling; soft-string versus stiff-string models, SPE-178197-MS, 2016, doi:10.2118/178197-MS.
6. Newman K.R., Finite element analysis of coiled tubing forces, SPE-89502-MS, 2004, doi:10.2118/89502-MS.
7. Newman K., Bhalla K., McSpadden A., Basic tubing forces model (TFM) calculation, Tech Note CTES, Texas, 2003.
8. Wu J., Juvkam-Wold H. C., Coiled tubing buckling implication in drilling and completing horizontal wells, SPE-26336-PA, 1995, doi:10.2118/26336-PA.
9. Feodos'ev V.I., Soprotivlenie materialov (Strength of materials), Moscow: Publ. of MSTU named after N.E.Bauman, 1999, 592 p.
10. Bhalla K., Walton I.C., The effect of fluid flow on coiled tubing reach,
SPE-36464-PA, 1998, doi:10.2118/36464-PA.
11. Kaya A.S., Comprehensive mechanistic modeling of two-phase flow in deviated wells, Oklahoma: The University of Tulsa, 1998, 93 p.
12. Caetano E.F., Upward vertical two-phase flow through an annulus: PhD dissertation, Oklahoma: The University of Tulsa, 1985.
13. Beggs H.D., Brill J.P., A study of two-phase flow in inclined pipes, JPT, 1973, May, pp. 607–617.
14. Zhang H.-Q., Wang Q., Sarica S., Bril J.P., Unified model for gas-liquid pipe flow via slug dynamics. Part 1: Model development, J. Energy Res. Technol., 2003, no. 125.
15. Avakov V.A., Foster J.C., Smith E.J., Coiled tubing life prediction, OTC-7325-MS, 1993, pp. 627–634.