Microscopic characteristics of water invasion and residual gas distribution in carbonate gas reservoirs
We used the nuclear magnetic resonance online detection method to analyze the water invasion mechanism and residual gas distribution of a carbonate rock gas reservoir. The T2 spectra obtained by using the Carr‐Purcell‐Meiboom‐Gill (CPMG) pulse sequence were applied to characterize the invasion water...
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Published in | Energy science & engineering Vol. 9; no. 11; pp. 2151 - 2164 |
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Main Authors | , , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
London
John Wiley & Sons, Inc
01.11.2021
Wiley |
Subjects | |
Online Access | Get full text |
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Summary: | We used the nuclear magnetic resonance online detection method to analyze the water invasion mechanism and residual gas distribution of a carbonate rock gas reservoir. The T2 spectra obtained by using the Carr‐Purcell‐Meiboom‐Gill (CPMG) pulse sequence were applied to characterize the invasion water and residual gas distribution. The results showed that (a) in the pore‐type gas reservoir, the water first invades the meso–macropores and then the small pores as the pressure decreases further. The fracture distribution in a fracture‐pore‐type gas reservoir has an effect on the water invasion mode. The water can enter the pores through the fracture wall after the water invades the fracture. (b) In the pore‐type gas reservoir, 37.7% of the residual gas resides in the small pores, while the rest resides in the macropores. While in the fracture‐pore‐type gas reservoir, 4.8% ~ 26.8% of the residual gas is in the smaller pores and 69.2% ~ 95.7% in the macropores. Barely, any residual gas resides in the fractures. The residual gas in the small pores is difficult to produce. (c) The residual gas is controlled by the fracture penetration, amount of bottom water, fracture width, and production rate. It is suggested the production rate decreased to induce the water to invade the meso–macropores after the gas well begins to produce water to reduce the amount of residual gas in the meso–macropores.
The nuclear magnetic resonance online detection method was used to analyze the water invasion mechanism and residual gas distribution of a carbonate rock gas reservoir, and theT2 spectra were obtained by using the Carr‐Purcell‐Meiboom‐Gill (CPMG) pulse sequence to characterize the intrusive water distribution |
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Bibliography: | Funding information National Science and Technology Major Project of China, grant number 2017ZX05030003‐003‐002;Fundamental Research Funds for the Central Universities, grant number 18CX02027A |
ISSN: | 2050-0505 2050-0505 |
DOI: | 10.1002/ese3.972 |