Patent ID: 11873712
Assignee: CHINA UNIVERSITY OF PETROLEUM—BEIJING
Field: Measurement (Instruments)
Classification: CPC E  G | IPC E  G

Claim 3:
4. The method according to claim 3, wherein the determining the initial gas pressure according to the actual recovery of the natural gas comprises:
calculating the initial gas pressure by substituting the actual recovery of the natural gas, a volume of the first intermediate container, a corresponding actual formation pressure when a gas reservoir is subjected to a water breakthrough, the initial formation pressure, a first gas deviation factor corresponding to the initial gas pressure, a second gas deviation factor corresponding to the actual formation pressure, a third gas deviation factor corresponding to the initial formation pressure, and a pore volume of the core into a formula, the formula being expressed as:, P
   g
  
  =
  
   
    
     iV
     s
    
    ⁢
    
     Z
     g
    
   
   
    
     V
     g
    
    (
    
     
      
       Z
       1
      
      
       P
       1
      
     
     -
     
      
       Z
       2
      
      
       P
       
        2
         
       
      
     
    
    )
   
  
 

wherein Pg is the initial gas pressure, i is the actual recovery of the natural gas, Vs is the pore volume of the core, Zg is the first gas deviation factor, Vg is the volume of the first intermediate container, Z1 is the second gas deviation factor, Z2 is the third gas deviation factor, P1 is the actual formation pressure, and P2 is the initial formation pressure.