Instructions - OFI Testing Equipment, Inc.
Instructions - OFI Testing Equipment, Inc.
Instructions - OFI Testing Equipment, Inc.
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<strong>OFI</strong> <strong>Testing</strong> <strong>Equipment</strong> – 146-00 <strong>Instructions</strong> – Workover and Completion Fluids Test Kit Page 7 of 17<br />
epm Calcium and Magnesium = mls of Hardness Titrating solution used x 2<br />
(If the solution strength is 1 ml = 2 epm Hardness)<br />
epm Calcium and Magnesium = mls of Hardness Titrating solution used x 20<br />
(If the solution strength is 1 ml = 20 epm Hardness)<br />
Usually the magnesium ion content is negligible, so the total Hardness is reported as being all Calcium.<br />
Therefore:<br />
mg/L Calcium = epm Total Hardness x 20<br />
More or less sample can be used to obtain a titration between 1 and 10 mls, in which case the results obtained above<br />
should be divided by the ml of sample used.<br />
epm = equivalent parts per million<br />
Sometimes the test is erratic at low temperatures due to the change in solubility of the ingredients.<br />
If desired, separate test may be performed for Calcium and Magnesium individually using Calcium Buffer<br />
solution and Calver II Indicator powder. See separate instructions.<br />
Various Buffer Indicator Combinations:<br />
1. Versenate Buffer solution (#205-04, Ammonium Hydroxide, pH = 12 –13) with Versenate Indicator (#205-02,<br />
Calmagite).<br />
2. Manver Indicator (#205-27) with Ammonium Hydroxide Buffer (#205-04, pH = 12 –13)<br />
3. Eriochrome Black T indicator (#205-28) with Ammonium Hydroxide Buffer<br />
(#205-04 pH = 12 –13)<br />
Water Based Drilling Fluids<br />
All of these combinations may be used to determine Total Hardness.<br />
CALCIUM ANALYSIS<br />
INSTRUCTIONS<br />
When Hardness Titration solution (EDTA) is added to water or mud filtrate that contains both Calcium and Magnesium,<br />
the EDTA first combines with the Calcium. Calcium alone can be determined with EDTA when the pH of the sample is<br />
sufficiently high so that magnesium is precipitated out as the Hydroxide, and an indicator specific to Calcium is used.<br />
Several indicators will give color changes when all of the Calcium has been complexed by the EDTA at a pH in the<br />
range of 12 to 13. An end point obscured by dark organic components may be treated by oxidizing with Sodium<br />
Hypochlorite.<br />
<strong>Equipment</strong>:<br />
#153-14 Graduated Cylinder, 50 ml x 1.0 ml, glass<br />
#153-34 Pipette, 1.0 ml x 1/100 ml, glass<br />
<strong>OFI</strong>TE • 11302 Steeplecrest Dr. • Houston, TX 77065 USA • Phone (832) 320-7300 • http://www.ofite.com<br />
Version 1.1<br />
Date 03-04-03