Investigation of the Water-Invasion Gas Efficiency in the Kela-2 Gas Field Using Multiple Experiments

Donghuan Han (), Wei Xiong, Tongwen Jiang, Shusheng Gao, Huaxun Liu, Liyou Ye, Wenqing Zhu and Weiguo An
Additional contact information
Donghuan Han: University of Chinese Academy of Sciences, Beijing 100049, China
Wei Xiong: Research Institute of Petroleum Exploration and Development, PetroChina, Beijing 100083, China
Tongwen Jiang: Department of Science and Technology Management, PetroChina Company Limited, Beijing 100007, China
Shusheng Gao: Research Institute of Petroleum Exploration and Development, PetroChina, Beijing 100083, China
Huaxun Liu: Research Institute of Petroleum Exploration and Development, PetroChina, Beijing 100083, China
Liyou Ye: Research Institute of Petroleum Exploration and Development, PetroChina, Beijing 100083, China
Wenqing Zhu: Research Institute of Petroleum Exploration and Development, PetroChina, Beijing 100083, China
Weiguo An: Research Institute of Petroleum Exploration and Development, PetroChina, Beijing 100083, China

Energies, 2023, vol. 16, issue 20, 1-22

Abstract: Although improving the recovery of water-invaded gas reservoirs has been extensively studied in the natural gas industry, the nature of the efficiency of water-invaded gas recovery remains uncertain. Low-field nuclear magnetic resonance (NMR) can be used to clearly identify changes in water saturation in the core during high-pressure water-invasion gas. Here, we provide four types of water-invasion gas experiments (spontaneous imbibition, atmospheric pressure, high-pressure approximate equilibrium, and depletion development water-invasion gas) to reveal the impact of the water-invasion gas efficiency on the recovery of water-invasion gas reservoirs. NMR suggested that imbibition mainly occurs in medium to large pores and that residual gas remains mainly in large pores. The amount of gas driven out from the large pores by imbibition was much greater than that driven out from the small pores. Our findings indicate that the initial gas saturation, contact surface, and permeability are the main factors controlling the residual gas saturation, suggesting that a reasonable initial water saturation should be established before the water-invasion gas experiments. Additionally, the water-invasion gas efficiency at high pressures can be more reliably obtained than that at normal pressures. After the high-pressure approximate equilibrium water invasion for gas displacement, a large amount of residual gas remains in the relatively larger pores of the core, with a residual gas saturation of 42%. In contrast to conventional experiments, the residual gas saturation and water displacement efficiency of the high-pressure approximate equilibrium water invasion for gas displacement did not exhibit a favorable linear relationship with the permeability. The residual gas saturation ranged from 34 to 43% (avg. 38%), while the water displacement efficiency ranged from 32 to 45% (avg. 40%) in the high-pressure approximate equilibrium water invasion for gas displacement. The residual gas saturation in the depletion development water-invasion gas experiment was 26–40% (average: 33%), with an efficiency ranging from 45 to 50% (average: 48%), indicating that the depletion development experiment is closer to the actual development process of gas reservoirs. Our findings provide novel insights into water-invasion gas efficiency, providing robust estimates of the recovery of water-invasion gas reservoirs.

Keywords: water-invasion gas efficiency; Kela-2 gas field; recovery rate; residual gas saturation; depletion development (search for similar items in EconPapers)
JEL-codes: Q Q0 Q4 Q40 Q41 Q42 Q43 Q47 Q48 Q49 (search for similar items in EconPapers)
Date: 2023
References: View references in EconPapers View complete reference list from CitEc
Citations:

Downloads: (external link)
https://www.mdpi.com/1996-1073/16/20/7216/pdf (application/pdf)
https://www.mdpi.com/1996-1073/16/20/7216/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jeners:v:16:y:2023:i:20:p:7216-:d:1265740

Access Statistics for this article

Energies is currently edited by Ms. Agatha Cao

More articles in Energies from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().