年間 4 号発行
ISSN 印刷: 2151-4798
ISSN オンライン: 2151-562X
Indexed in
EXPERIMENTS ON THE PERMEABILITY LIMITS OF TIGHT OIL RESERVOIRS FOR GAS FLOOD RECOVERY
要約
The exploitation of a tight reservoir is characterized by low single-well yield and a rapid drop in the yielding rate. The pore throat characteristic of the reservoir is one of the primary influencing factors. The size of the pore throat radius directly affects oil production. In this study, a relationship between the average throat radius and the core permeability is determined through high-pressure mercury penetration experiments based on parallel core samples taken from tight oil reservoir Block A in Changqing, China. The thickness of the bound water film is analyzed and calculated via centrifugal, nuclear magnetic resonance, and cryogenic nitrogen adsorption tests. The lower limit of the throat radius in the gas injection is determined through centrifugal and gas flooding tests, and finally the permeability limit during gas injection in the reservoirs of the block is determined. The results have proven that: (1) the pore throat radius values at Block A are mainly on the nanoscale level; (2) the range of the bound water film thickness at Block A is between 5.27 and 16.71 nm, with an average value of 10 nm; (3) when the permeability value is smaller than 0.01 mD, the bound water film thickness increases sharply with the decrease in permeability; and (4) the range of the lower limit of the throat radius during gas injection in the tight reservoirs of Block A is between 25.27 and 36.71 nm, with an average of 30 nm. This indicates that gas injection flooding is applicable only when the permeability is greater than 0.01 mD. A novel method is proposed in this paper for calculating the bound water film thickness, which can be used as a reference for oil-recovery in similar tight oil reservoirs.
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Udy Jackson, Hansen Brigham, Maddux Sage, Petersen Donald, Heilner Spencer, Stevens Kevin, Lignell David, Hedengren John, Review of Field Development Optimization of Waterflooding, EOR, and Well Placement Focusing on History Matching and Optimization Algorithms, Processes, 5, 3, 2017. Crossref
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Alonso Gerard, Gamallo Pablo, Rincón Cristina, Sayós Ramón, Interfacial behavior of binary, ternary and quaternary oil/water mixtures described from molecular dynamics simulations, Journal of Molecular Liquids, 324, 2021. Crossref
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Xiao Qianhua, Wang Zhiyuan, Yang Zhengming, Xiang Zuping, Liu Zhonghua, Yang Wei, Novel method for determining the lower producing limits of pore-throat radius and permeability in tight oil reservoirs, Energy Reports, 7, 2021. Crossref