Patent ID: 11946327
Assignee: YANGTZE UNIVERSITY
Field: Measurement (Instruments)
Classification: CPC E  G  Y | IPC E  G

Claim 2:
3. The automatic measuring method according to claim 2, wherein: the rheological parameters for the power law model, Bingham model and Herschel-Bulkley model are calculated with the-pressure and the flow rate; the calculation method is defined as following for drilling fluid flow in conventional pipeline; when the test fluid is power law fluid, rheological parameters are calculated as:, 8
        ⁢
        V
      
      D
    
    =
    
      
        4
        ⁢
        
          
        
        ⁢
        n
      
      
        
          
            (
            
              τ
              b
            
            )
          
          3
        
        ⁢
        
          K
          
            3
            n
          
        
      
    
  
  ⁢
  
    
      
        τ
        b
      
      
        
          
            3
            ⁢
            
              
            
            ⁢
            n
          
          +
          1
        
        n
      
    
    
      
        3
        ⁢
        
          
        
        ⁢
        n
      
      +
      1
    
  

where K is the consistency coefficient, n is the fluidity index, V is the average flow velocity, τb is the shear stress on the cylindrical surface, and D represents the diameter of the conventional pipeline;
for Bingham fluid, the formula for rheological parameters calculation is:, 8
      ⁢
      V
    
    D
  
  =
  
    
      
        τ
        b
      
      
        μ
        p
      
    
    ⁡
    
      [
      
        1
        -
        
          
            4
            ⁢
            
              
            
            ⁢
            
              τ
              0
            
          
          
            2
            ⁢
            
              
            
            ⁢
            
              τ
              b
            
          
        
        +
        
          
            1
            3
          
          ⁢
          
            
              (
              
                
                  τ
                  0
                
                
                  τ
                  b
                
              
              )
            
            4
          
        
      
      ], where τ0 is the fluid dynamic shear force and μp is the plastic viscosity;
for Herschel-Bulkley fluid, the formula for rheological parameters calculation is:, 8
      ⁢
      V
    
    D
  
  =
  
    
      
        4
        ⁢
        
          
        
        ⁢
        n
      
      
        
          (
          
            1
            +
            
              6
              ⁢
              
                
              
              ⁢
              n
            
            +
            
              11
              ⁢
              
                
              
              ⁢
              
                n
                2
              
            
            +
            
              6
              ⁢
              
                
              
              ⁢
              
                n
                3
              
            
          
          )
        
        ⁢
        
          
            (
            
              τ
              b
            
            )
          
          3
        
        ⁢
        
          K
          
            1
            n
          
        
      
    
    ⁢
    
      {
      
        
          
            [
            
              
                τ
                b
              
              -
              
                τ
                0
              
            
            ]
          
          
            
              n
              +
              1
            
            n
          
        
        ⁡
        
          [
          
            
              2
              ⁢
              
                
              
              ⁢
              
                n
                2
              
              ⁢
              
                τ
                0
                2
              
            
            +
            
              2
              ⁢
              
                
              
              ⁢
              
                n
                ⁡
                
                  (
                  
                    n
                    +
                    1
                  
                  )
                
              
              ⁢
              
                τ
                0
              
              ⁢
              
                τ
                b
              
            
            +
            
              
                (
                
                  
                    2
                    ⁢
                    
                      
                    
                    ⁢
                    n
                  
                  +
                  1
                
                )
              
              ⁢
              
                (
                
                  n
                  +
                  1
                
                )
              
              ⁢
              
                τ
                b
                2
              
            
          
          ]
        
      
      }
    
  

for Carson fluid, the formula for rheological parameters calculation is:, 8
      ⁢
      V
    
    D
  
  =
  
    
      4
      
        
          
            (
            
              τ
              b
            
            )
          
          3
        
        ⁢
        
          μ
          ∞
        
      
    
    ⁡
    
      [
      
        
          
            τ
            b
          
          6
        
        -
        
          
            2
            5
          
          ⁢
          
            
              (
              
                
                  τ
                  c
                
                ⁢
                
                  τ
                  b
                
              
              )
            
            
              0
              .
              5
            
          
        
        +
        
          
            τ
            c
          
          4
        
      
      ]
    
  

where τc the dynamic shear force for Carson fluid and μ∞ is the ultimate shear viscosity.