Page 271 - Geochemistry of Oil Field Waters

PALMER’S CLASSIFICATION 25 5

ties of the water; e.g., the principal soluble decomposition products of the
oldest rock formations are the alkalies (primary), while more recent rock
formations are the principal source of the alkaline earths (secondary), This
theory of Palmer’s that the terms primary and secondary are associated with
the age of the rock should not necessarily be considered undisputably true,
because primary salinity certainly can be acquired from other soluble
material than that derived directly from decomposition products of the
oldest rock formations.
The five special properties of water are:
(1) Primary salinity (alkali salinity); that is, salinity not to exceed twice
the sum of the reacting values of the radicles of the alkalies.
(2) Secondary salinity (permanent hardness); that is, the excess (if any) of
salinity over primary salinity, not to exceed twice the sum of the reacting
values of the radicles of the alkaline earths group.
(3) Tertiary salinity (acidity); that is, the excess (if any) of salinity over
primary and secondary salinity.
(4) Primary alkalinity (permanent alkalinity); that is, the excess (if any) of
twice the sum of the reacting values of the alkalies over salinity.
(5) Secondary alkalinity (temporary alkalinity); that is, the excess (if any)
of twice the sum of the reacting values of the radicles of the alkaline earths
group over secondary salinity.
Reacting values in percent are used in this system. The percentage values
are determined by summing the milliequivalents of all the ions, dividing the
milliequivalents of a given ion by the sum of the total milliequivalents, and
multiplying by 100. Waters are classified by numerical values of the relation-
ships of anions to the cations, where a, b, and d represent the percentage
values of the alkali cations, alkaline earth cations, and strong acid anions,
respectively. Any one of the following five conditions may exist: d may be
equal to or less than a, greater than a and less than a + by equal to a + by or
greater than a + b. Using these conditions, waters are classified into five
classes :

Classl: d<a
2d = primary salinity
2(a - d) = primary alkalinity
2b = secondary alkalinity

Class 2: d = a
2u or 2d = primary salinity
2b = secondary alkalinity

Class 3: d >a; d < (a + b)
2a = primary salinity
2(d -a) = secondary salinity
2(a + b - d) = secondary alkalinity