Determination of reservoir properties of elastic gas condensate formations based on two field measurements at a steady-state inflow

UDK: 622.276.1/.4
DOI: 10.24887/0028-2448-2022-4-49-53
Key words: initial permeability, reservoir compacting, permeability change law, two-phase filtration, interpretation, well-testing, permeability change factor
Authors: M.A. Jamalbayov (SOCAR OilGasScientificResearchProject Institute, Baku, Azerbaijan), T.M. Jamalbayli (Azerbaijan State Oil and Industry University, Baku, Azerbaijan)

A method is proposed for interpreting the results of gas condensate well test data in two steady-state regime in order to determine the initial value of the reservoir effective permeability and its change factor. The described technique was developed on the basis of a binary filtration model, where the hydrocarbon system is represented as consisting of two pseudo-components and two phases, between the phases there is a mass transfer of hydrocarbons. To apply the proposed methodology, well production data is required, measured at two different steady-state well conditions for two different reservoir pressures. The technique has been tested on the example of PVT production data for the horizon X of the Bulla-Deniz field (Azerbaijan) at different compacting factors of reservoir rocks. The high reliability of the described method has been established. At the initial stages of development, the deviation of the calculated values of the considered parameters from their actual values did not reach 1%. And at later periods, i.e. when the reservoir pressure falls below than 80%, the deviations of the calculated initial permeability and permeability change factor were 2.3 and 4.6%, respectively. Unlike similar methods, the proposed approach is based on the idea of linear approximation. This made it possible to minimize the input data (the number of measurements) and at the same time increased the reliability of interpretation by eliminating the subjectivity factor. The proposed method is simple and reliable, as evidenced by the test results. It is easy to use in a computer, which is not unimportant when automating the process of interpreting measurement results.


1. AbasovM.T., Orudjaliev F.G., Djamalbekov M.A., Scientific basis gas condensate reservoirs development in deformed reservoir rocks, Proceedings of the II Symposium on Mining Chemistry, Visegrad, 1986, 22–24 October, pp. 187–206.

2. Aliev F.A., Jamalbayov M.A., Hasanov I.R. et al., Mathematical modeling of the nonlinear filtration process of volatile oils to a well in a compacting formation, Proceedings of the 6th international conference on control and optimization with industrial applications, 2018, V. II, pp. 59–61.

3. Dubrule, O., Haldorsen, H.H., Geostatistics for permeability estimation, In: Reservoir characterization: edited by Lake L.W.,  Caroll H.B. Jr., New York: Academic Press, 1986.

4. Farshidi S., Yu D.F., Slade J. et al., Permeability estimation from inflow data during underbalanced drilling, Journal of Canadian Petroleum Technology, 2008, June, V. 47, no. 6, pp. 56–63.

5. Guo Junxin, Estimation of permeability and viscoelastic properties of shale by three-point bending test, SEG Annual Meeting, 18-23 October 2015, New Orleans, Louisiana, 2015.

6. Angeles R., Torres-Verdin C., Lee H.-J. et al., Estimation of permeability and permeability anisotropy from straddle-packer formation-tester measurements based on the physics of two-phase immiscible flow and invasion, SPE-95897-PA, 2007.

7. Wendt W.A., Sakurai S., Nelson P.H., Permeability prediction from well logs using multiple regression in lake, New York: Academic Press, 1986.

8. Gorbunov A.T., Razrabotka anomal'nykh neftyanykh mestorozhdeniy (Development of abnormal oil fields), Moscow: Nedra Publ., 1981, 237 p.

9. Khasanov M.M., Spivak S.I., Yulmukhametov D.R., Permeability determination from log data as an incorrectly set problem (In Russ.), Neftegazovoe delo, 2005, V. 3, no. 1, pp. 155–166.

10. Shor Ya.B., Statisticheskie metody analiza i kontrolya kachestva i nadezhnosti (Statistical methods of analysis and quality and reliability control), Moscow: Publ. of Gosenergoizdat, 1962, 552 p.

11. Hasanov I.R., Jamalbayov M.A., A stationary oil inflow to the wellbore taking into account the initial pressure gradient, Arab J Geosci., 2020, V. 13, no. 833,,

12. Jamalbayov M.A., Veliyev N.A., The technique of early determination of reservoir drive of gas condensate and velotail oil deposits on the basis of new diagnosis indicators, TWMS J. Pure Appl. Math., 2017, V.8, no. 2, pp. 236–250.

13. Denney D., HP/HT gas-condensate well testing for the Shell Onyx SW Prospect, JPT, 2008, V. 60I, no. 2,

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