© 2019 Department of Petroleum Resources. All rights reserved Department of Petroleum Resources (DPR) PROCEDURE GUIDE

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CTL = exp {-α𝛥𝑡[1 + 0.8α(𝛥𝑡+ 𝛿)} 
c) Pressure Correction Factor for Steel (CPS)                
  This shall be computed from the following formula: 
CPS = 1 + {
(𝑃∗𝐷)
(𝐸∗𝑡)} 
   Where P = observed pressure, psi 
                 D = internal diameter of prover, inches 
                  t = wall thickness of prover, inches 
                  E = Modulus of Elasticity 
d) Pressure Corrections Factor for Liquid, i.e. Compressibility, (CPL)  
     This shall be computed from the following formula: 
CPL =  
1
{1−(𝑃∗𝐹)} 
             
 Where P = observed pressure, psi 
               F = Compressibility factor of the medium of calibration 
F = exp {A+Bt+
𝐶+𝐷𝑡
𝜌2 } 
2.6.4.2 Proving Reports 
2.6.4.2.1 Department of Petroleum Resources representative(s) shall witness prover/meter 
calibrations and endorse field data generated there from.  
2.6.4.2.2 Final calibration certificate/report for the newly generated base prover volume 
(BPV) shall be approved by the Director DPR. Calibration for subsequent year shall 
commence on site at least three (3) months before the expiration of the current base 
volume(s).  Pending the approval of the new base volume(s), previous base 
volume(s) shall be used. Validity of all base volumes shall be 12 months. 
2.6.5    Rules Governing Meter Proving 
2.6.5.1 A meter shall be proved to obtain an initial meter factor as soon as the meter is 
installed for use in a facility. 
2.6.5.2 Thereafter, if the meter is in use as the only means of determining the fiscalized 
production of a company in a given area it should be proved fortnightly but if 
installed on an export facility it should be proved during every loading exercise.  
2.6.5.3 If the meter is installed in any other type of facility it shall be proved once every 
month. 
2.6.5.4 If a meter is removed for service/maintenance, it shall be proved before it is put back 
into operation. 
2.6.5.5 During export meter proving, the repeatability of each set of five (5) proving runs 
shall check within 0.040% repeatability while for production, allocation and custody 
transfer meters, repeatability shall be 0.050%.