Well testing is the most important tool for determining the filtration and capacity properties of formations, studying their geological structure and efficient management of oil field development. Traditional methods (the pressure build-up) require the stop of production, which reduces economic efficiency, especially in mature fields. The article proposes new models for well testing interpretation of wells operating with a variable flow rate. New approaches enable to conduct well testing without stopping wells, which minimize production losses and increase the profitability. A model of a closed rectangular formation with impermeable boundaries and a model of an infinite formation with dual porosity or permeability are considered. Various filtration regimes are described: radial, pseudo-steady-state in a closed formation, and transient processes in reservoirs with dual porosity and permeability. One aspect of the work is the application of the superposition principle to obtain a solution to the piezoconductivity equation under specified conditions and subsequent analysis of bottomhole pressure. This enables to interpret data highly accurate even under changing production rates. The results of such interpretation are compared with the results of classical interpretation using the best fit method. These approaches can be used in mature fields and in new ones, providing increased accuracy of formation property assessment, improved development control, and an increase in the economic efficiency of production due to the absence of losses during well testing and due to obtaining additional information on a larger number of wells. The application of these methods can become the basis for optimizing field operation in the long term.
References
1. Chaudhry A., Oil well testing handbook, Elsevier, 2004, 525 p.
2. Buzinov S.N., Umrikhin I.D., Issledovanie neftyanykh i gazovykh skvazhin i plastov (The study of oil and gas wells and reservoirs), Moscow: Nedra Publ., 1984, 269 p.
3. Kul’pin L.G., Myasnikov Yu.A., Gidrodinamicheskie metody issledovaniya neftegazovodonosnykh plastov (Hydrodynamic study of oil-gas-water-bearing strata), Moscow: Nedra Publ., 1974, 200 p.
4. Bourdet D., Well test analysis: The use of advanced interpretation models, Boston, Elsevier Science, 2002, 436 p.
5. Earlougher R.C. Jr., Advances in well test analysis, SPE Monograph Series, V. 5, 1977, 264 p.
6. Sova E.V., Sova V.E., Efficiency of application of the research technique at two flow rates to reduce the cost of hydrodynamic testing of production wells (In Russ.), Geologiya, 9. Osnovy ispytaniya plastov (Formation testing fundamentals): edited by Zagurenko A.G., Moscow-Izhevsk: Publ. of Institute of Computer Research, 2012, 432 p.
geografiya i global’naya energiya, 2009, no. 2(33), pp. 76-79.
7. Gulyaev D.N., Batmanova O.V., Pulse-code test and multi-well deconvolution algorithms are new technologies for reservoir properties determination between the wells (In Russ.), Vestnik Rossiyskogo novogo universiteta. Seriya: Slozhnye sistemy: modeli, analiz, upravlenie, 2017, no. 4, pp. 26–32.
8. Fundamentals of formation testing, Schlumberger, 2008.
9. Aslanyan A., Kovalenko I., Ilyasov I. et al., Waterflood study of high viscosity saturated reservoir with multiwell retrospective testing and cross-well pressure pulse-code testing, SPE-193712-MS, 2018, DOI: http://doi.org/10.2118/193712-MS
10. Cumming J.A., Wooff D.A., Whittle T., Gringarten A.C., Multiwell deconvolution, SPE-166458-PA, 2014, DOI: http://doi.org/10.2118/166458-PA
11. Houze O., Viturat D., Fjaere O.S. et al., Dynamic data analysis. V 5.42, Kappa Engineering, 2022, 772 p.
12. Von Schroeter T., Hollaender F., Gringarten A.C., Deconvolution of well-test data as a nonlinear total least-squares problem, SPE-71574-MS, 2004,
DOI: http://doi.org/10.2118/71574-MS
13. Kremenetskiy M.I., Ipatov A.I., Gulyaev D.N., Informatsionnoe obespechenie i tekhnologii gidrodinamicheskogo modelirovaniya neftyanykh i gazovykh zalezhey (Information support and technologies of hydrodynamic modeling of oil and gas deposits), Moscow - Izhevsk: Publ. of Izhevsk Institute of Computer Research, 2012, 896 p.
14. Afanaskin I.V., Kolevatov A.A., Glushakov A.A., Mathematic model for well test interpretation in wells producing with altered flow rates in homogeneous reservoir
(In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2023, no. 4, pp. 52–55, DOI: http://doi.org/10.24887/0028-2448-2023-4-52-55
15. Afanaskin I.V., Kolevatov A.A., Glushakov A.A., Mathematic models for well test interpretation in wells producing with altered flow rates in reservoir with strait no-flow boundary and in reservoir with two parallel no-flow boundaries (In Russ.), Neftepromyslovoe delo, 2023, no. 8(656), pp. 12–17, DOI: https://doi.org/10.33285/0207-2351-2023-8(656)-12-17
16. Glushakov A.A., Pivovarov D.E., Afanaskin I.V., Kolevatov A.A., Mathematical model for interpretation of hydrodynamic studies data of wells with variable production in a semi-endless strip (In Russ.), Geologiya, geofizika i razrabotka neftyanykh i gazovykh mestorozhdeniy, 2024, no. 8(392), pp. 34–42.
17. Deeva T.A., Kamartdinov M.R., Kulagina T.E., Mangazeev P.V., Gidrodinamicheskie issledovaniya skvazhin: analiz i interpretatsiya dannykh (Well test: analysis and interpretation of data), Tomsk: Publ. of TPU, 2009, 243 p.
18. Dietz D.N., Determination of average reservoir pressure from build-up surveys, J. Pet. Tech., 1965, Aug., pp. 955–959, DOI: https://doi.org/10.2118/1156-PA
