Patent ID: 11965844
Assignee: SCHLUMBERGER TECHNOLOGY CORPORATION
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 15:
16. A method according to claim 1, wherein:
the processing of iv) involves inversion of the NMR data written in a two-dimensional matrix form of

M=K1·F·K2T,

where M is a two-dimensional matrix whose rows correspond to a number of echoes in the detected resulting NMR signals and whose columns corresponds to different applied experimental pressure values,
F is a two-dimensional matrix whose rows correspond to different transverse relaxation values and whose columns corresponds to different capillary pressure values,
K1 is a two-dimensional kernel matrix where element (i,j) of K1 is defined to be, K
    ⁢
    
     1
     
      i
      ⁢
      j
     
    
   
   =
   
    exp
    [
    
     -
      
     
      
       t
       i
      
      
       T
       
        z
        ,
        j
       
      
     
    
    ]
   
  
  ,
 

where ti is an i-th value of an echo time t for the echoes over j transverse relaxation values of the F matrix;
T2 represents a dimension of the transverse relaxation values; and
K2 is a two-dimensional kernel matrix defined as:

K2kl=Sw(Pcent,k,Pc,l),

where Sw(Pcent,k,Pc,l) is a step function or modified step function representing saturation of the pore sample as a function of applied experimental pressure.