Optimization of cycling process planning at gas condensate fields using neural network approach

Background. The development of gas condensate fields (GCF) using conventional depletion-based approaches is accompanied by the irreversible loss of significant amounts of condensate within the reservoir and a substantial decline in gas well productivity. Currently, the search for alternative approaches to developing this type of reservoirs, involving reservoir management techniques, is a high-priority objective.

Aim. Gas cycling is an approach for GCF development, involving reservoir management, which is widely and successfully applied in global practice. This approach aims to maintain reservoir pressure and vaporize hydrocarbons from the condensed liquid back into the dry gas that flows through the reservoir. In this work, we address the problem of designing and optimizing gas cycling by determining the fraction of dry gas to be returned to the reservoir, the start time of injection, and the injection duration — the parameters that govern the economic effectiveness of GCF development.

Materials and methods. A series of simulations were performed using a compositional reservoir model, with variations in the composition of the gas condensate mixture, the reservoir pressure at the start of injection, the injection duration, and the fraction of dry gas returned to the reservoir. An economic model to calculate the net present value for each injection scenario was created. A neural network model was trained and tested.

Results. Neural network technologies were used to develop an algorithm and a software program to select the optimal volume of gas reinjection, the start time of injection, and its duration. The steps include reproducing the results of the reservoir simulations and determining the scenario and parameters of gas injection that provide maximum economic efficiency of the gas cycling process under given economic conditions.

Conclusion. The developed algorithm and software program represent a tool for a prompt selection of the optimal gas cycling implementation option for given geological and physical characteristics of the reservoir, the composition and properties of the reservoir gas, as well as economic conditions. This option can be further elaborated in detail using a full-scale reservoir model during the design and management of the GCF development process.

1. Akhmetzhan S.Z., Kupeshova A.S., Sabitov A.K., Nursultanov E.K., Aishov N.K. Current state of gas reinjection issues atthe Karachaganak field. Sustainable Innovative Development: Design and Management, 2022, Vol. 18, No. 3(56), P. 7—15 (In Russ.).

2. Volzhenina D.A., Sharf I.V., Sabanchin I.V. Analysis of the efficiency of using cycling technology in the development of gas condensate deposits. TPU Bulletin, 2020, No. 5, pp. 18—25 (In Russ.).

3. Gritsenko A.I., Ter-Sarkisov R.M., Shandrygin A.N., Podyuk V.G. Methods for increasing the productivity of gas condensate wells. Moscow: Nedra Publ., 1997. 364 p. (In Russ.).

4. Kachalov V.V., Sokotuschenko V.N., Zemlyanaya E.V., Volokhova A.V. Review of methods for increasing component recovery in the development of gas condensate fields. Science. Innovations. Technologies, 2019. No. 3. P. 19—48 (In Russ.).

5. Kolbikov S.V., Prokaev V.A. Evaluation of the impact of double taxation on the efficiency of gas condensate field development using the cycling process. Subsurface Management in XXI century, 2009. No. 3. P. 76—80 (In Russ.).

6. Lyugay A.D. Increasing component recovery in the development of gas condensate fields with high content of non-hydrocarbon components (using the Astrakhan gas condensate field as an example). Cand. techn. sci. diss. Moscow, 2016. 26 p. (In Russ.).

7. Makarov E.S., Yushkov A.Yu., Romanov A.S. Study of methods for additional extraction of gas condensate from Achimov formations on a hydrodynamic model. Vestnik Tyumenskogo gosudarstvennogo universiteta. Oil, gas, energy. 2017. Vol. 3. No. 1. P. 79—90 (In Russ.). DOI: 10.21684/2411-7978-2017-3-1-79-90

8. Cheban S.E., Mulyavin S.F. Increasing the condensate recovery coefficient using cycling process technology. News of higher educational institutions. Oil and Gas,.2016. No. 2. P. 86—92 (In Russ.). DOI: 10.31660/0445-0108-2016-2-86-92

9. Yushkov A.Yu., Makarov P.V. Evaluation of cycling options at the achimovsky layers of the Urengoy field. Oilfield Engineering. 2015. No. 4. P. 38—53 (In Russ.).

10. Abbasov Z.Y., Fataliyev V.M. The effect of gas-condensate reservoir depletion stages on gas injection and the importance of the aerosol state of fluids in this process. Journal of Natural Gas Science and Engineering. 2016. No. 31. P. 779—790. DOI: 10.1016/j.jngse.2016.03.079

11. Burachok O. Enhanced Gas and Condensate Recovery: Review of Published Pilot and Commercial Projects. Nafta-Gaz. 2021. Vol. 1. P. 20—25. DOI: 10.18668/NG.2021.01.03

12. Doroshenko V., Titlov A.O. Development of technology of gas condensate extraction from the formation in the conditions of retrograde condensation. Technology audit and production reserves. 2021. No. 1/3(57). P. 12—15. DOI: 10.15587/2706-5448.2021.225212

13. Kolbikov S.V. Gas-Condensate Recovery For The Low Permeable Sands, Gas Cycling Efficiency. SPE Russian Oil and Gas Conference and Exhibition. Moscow, Russia, 2010. SPE 136380. DOI: 10.2118/136380-MS

14. Sharafutdinov R., Tyurin V., Fateev D., Skvortsov S., Dolgikh Yu., Tokarev D., et al. Practical Application of High-Resolution Reservoir Simulation and HighPerformance Computing for Accurate Modeling of Low Permeability Gas Condensate Reservoirs Production. SPE Russian Petroleum Technology Conference. Russia, 2019. DOI: 10.2118/196916-MS

15. Siddiqui M. A. Q., Alnuaim S., Khan R. Stochastic Optimization of Gas Cycling in Gas Condensate Reservoirs. Abu Dhabi International Petroleum Exhibition and Conference. UAE, 2014. SPE-172107- MS 2014 10.2118/172107-MS.

16. Suhendro S. Review of 20 Years Hydrocarbon Gas Cycling in the Arun Gas Field. SPE/IATMI Asia Pacific Oil & Gas Conference and Exhibition. Indonesia, 2017. SPE-186280-MS. DOI: 10.2118/186280-MS

17. Udovchenko O., Blicharski J., Matiishyn L. A Case Study of Gas-Condensate Reservoir Performance with Gas Cycling. Archives of Mining Sciences. 2024. No. 9 (1). P. 25—49. DOI: 10.24425/ams.2024.149825