Changes

===Analytical methods===

===Analytical methods===

<gallery mode=packed heights=300px widths=300px>

<gallery mode=packed heights=300px widths=300px>

oilfield-water-analysis_fig1.png|{{figure number|1}}Triangular plot showing relative amounts of cations in typical oil field brines. Relative amount of sodium changes, but calcium is always about five times magnesium. (After Dickey.<ref name=pt05r46>Dickey, P. A., 1966, [http://archives.datapages.com/data/bulletns/1965-67/data/pg/0050/0011/2450/2472.htm Patterns of chemical composition of deep subsurface waters: AAPG Bulletin, v. ]50, p. 2472–2478.</ref>)

oilfield-water-analysis_fig1.png|{{figure number|1}}Triangular plot showing relative amounts of cations in typical oil field brines. Relative amount of sodium changes, but calcium is always about five times magnesium. (After Dickey.<ref name=pt05r46>Dickey, P. A., 1966, [http://archives.datapages.com/data/bulletns/1965-67/data/pg/0050/0011/2450/2472.htm Patterns of chemical composition of deep subsurface waters: AAPG Bulletin], v. 50, p. 2472–2478.</ref>)

file:oilfield-water-analysis_fig2.png|{{figure number|2}}Stiff<ref name=pt05r149 /> diagrams used to show water compositions on maps.

file:oilfield-water-analysis_fig2.png|{{figure number|2}}Stiff<ref name=pt05r149 /> diagrams used to show water compositions on maps.

</gallery>

</gallery>

|+ {{table number|1}}Example calculations to convert milligrams per liter to milliequivalents and milliequivalent percent

|+ {{table number|1}}Example calculations to convert milligrams per liter to milliequivalents and milliequivalent percent

|-

|-

! rowspan = 2 | Element || rowspan = 2 |  Factor || colspa= 3 | Water 1 || colspan = 3 | Water 2 

! rowspan = 2 | Element || rowspan = 2 |  Factor || colspan= 3 | Water 1 || colspan = 3 | Water 2 

|-

|-

| mg/L || meq || meq % || mg/L || meq || meq %

! mg/L || meq || meq % || mg/L || meq || meq %

|-

|-

| Na⁺

| Na⁺ || 0.0435 || 44,100 || 1918 || 74 || 3040 || 132.2 || 99

| 0.0435

| 44,100

| 1918

| 74

| 3040

| 132.2

| 99

|-

|-

| Ca²⁺

| Ca²⁺ || 0.0499 || 11,000 || 549 || 20 || 21 || 1.0 || 0.5

| 0.0499

| 11,000

| 549

| 20

| 21

| 1.0

| 0.5

|-

|-

| Mg²⁺

| Mg²⁺ || 0.0823 || 1,500 || 123 || 6 || 7 || 0.6 || 0.5

| 0.0823

| 1,500

| 123

| 6

| 7

| 0.6

| 0.5

|-

|-

| Total cations

| '''Total cations''' || colspan = 2 | || '''2590''' || '''100''' || || '''133.8''' || '''100'''

|

 

|

 

| 2590

| 100

|

 

| 133.8

| 100

|-

|-

| Cl^–

| Cl^– || 0.0282 || 91,800 || 2589 || 100 || 3240 || 91.4 || 70

| 0.0282

| 91,800

| 2589

| 100

| 3240

| 91.4

| 70

|-

|-

| SO₄^2–

| SO₄^2– || 0.0208 || None || — || — || 407 || 8.5 || 6.5

| 0.0208

| None

| —

| —

| 407

| 8.5

| 6.5

|-

|-

| HCO₃^–

| HCO₃^– || 0.0164 || 34 || 0.5 || — || 1870 || 30.7 || 23.5

| 0.0164

| 34

| 0.5

| —

| 1870

| 30.7

| 23.5

|-

|-

| Total anions

| '''Total anions''' || colspan = 2 | || '''2590''' || '''100''' || || '''130.6''' || '''100.0'''

|

 

|

 

| 2590

| 100

|

 

| 130.6

| 100.0

|}

|}

[[Category:Laboratory methods]]

[[Category:Laboratory methods]]