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

Page 31 of 114
 
30 | P a g e 
 
 
Expected Water Cut (%) 
Approximate Sample Size (ml) 
50.1    -    100.0 
5 
25.1    -    50.0 
10 
10.1     -    25.0 
20 
5.1     -    10.0 
50 
1.1    -      5.0 
100 
0.5    -      1.0 
200 
Less than 0.5 
200 
 
3.3.3.2 Care shall be taken when pouring the sample into the graduated cylinder to avoid 
entrapment of air. Also, the level shall be adjusted as closely as possible to the appropriate 
graduation. 
3.3.3.3 The sample contents of the cylinder shall in turn be carefully poured into the 
distillation flask and the cylinder shall be rinsed, a minimum of five times, with xylene or 
any other acceptable solvent of a quantity equivalent to one-fifth of the capacity of the 
graduated cylinder, into the flask, such that the cylinder shall be thoroughly drained into it. 
3.3.4 Calibration of the Distillation Assembly 
The entire distillation assembly including the trap shall be calibrated prior to use in the 
following manner: 
3.3.4.1 Calibration of Water Trap 
3.3.4.1.2 The accuracy of the graduation marks on the trap shall be verified by adding 0.5 
milliliter increments of distilled water, at 20ᵒC, from a 5 milliliter micro-burette or 
micropipette readable to the nearest 0.01 milliliter graduation. If a deviation of more than 
0.05 milliliter between the quantity of water added and that observed is recorded, then the 
trap shall not be used until recalibrated. 
3.3.4.2 Calibration of the Apparatus 
3.3.4.2.1 The entire apparatus shall be calibrated by using xylene with known water content 
and to which known quantities of water shall be added and tested in turn as follows: 
The quantity of xylene to be used shall be exactly 400 milliliters of known value of water 
content which shall not be more than 0.02% water volume. 
The primary water content of the solvent shall be determined by distillation in the flask and 
measuring the entrapped water in the trap, which in turn shall be emptied and cleaned 
preparatory for further calibration test. 
3.3.4.2.2 Thereafter, a quantity of 1.00±0.01 milliliter distilled water at 20ᵒC shall with the 
use of a burette or pipette be added to the xylene in the distillation flask and tested as 
above. The test shall thereafter be repeated with the addition of 1.00±0.01 milliliter of 
distilled water at 20ᵒC and the result analyzed.  The maximum or minimum permissible 
water recovery for both tests shall not be more than 1.00±0.025 milliliter in the first case