Controlling salt contaminated drilling fluids with ethylene dicarboxylic acid

Claim 2

Method of controlling the rheology of a fresh water drilling fluid that has been contaminated with a salt selected from the group consisting of sodium chloride, potassium chloride and mixtures thereof, by adding to said salt contaminated drilling fluid a ethylenedicarboxylic acid selected from the group consisting of maleic acid, fumaric acid and maleic acid anhydride, in an amount of from about 0.5 to about 6 pounds per barrel of drilling fluid.

Claim 3

METHOD OF CONTROLLING THE RHEOLOGY OF A FRESH WATER DRILLING FLUID THAT HAS BEEN CONTAMINATED WITH A SALT SELECTED FROM THE GROUP CONSISTING OF SODIUM CHLORIDE, POTASSIUM CHLORIDE AND MIXTURES THEREOF, BY ADDING TO SAID SALT CONTAMINATED DRILLING FLUID A ETHYLENEDICARBOXYLIC ACID SELECTED FROM THE GROUP CONSISTING OF MALIEC ACID, FURAMIC ACID AND MALIEC ACID ANHYDRIDE, IN AN AMOUNT OF FROM ABOUT 0.5 TO ABOUT 6 POUNDS PER BARREL OF DRILLING FLUID.

Claim 4

METHOD OF CONTROLLING THE RHEOLOGY OF A FRESH WATER DRILLING FLUID THAT HAS BEEN CONTAMINATED WITH A SALT SELECTED FROM THE GROUP CONSISTING OF SODIUM CHLORIDE, POTASSIUM CHLORIDE AND MIXTURES THEREOF, BY ADDING TO SAID SALT CONTAMINATED DRILLING FLUID A ETHYLENEDICARBOXYLIC ACID SELECTED FROM THE GROUP CONSISTING OF MALIEC ACID, FURAMIC ACID AND MALIEC ACID ANHYDRIDE, IN AN AMOUNT OF FROM ABOUT 0.5 TO ABOUT 6 POUNDS PER BARREL OF DRILLING FLUID.

Claim 5

Method as claimed in claim 1 wherein said ethylenedicarboxylic acid is maleic acid.

Claim 6

Method as claimed in claim 1 wherein said ethylenedicarboxylic acid is maleic acid anhydride.

Claim 7

Method as claimed in claim 1 wherein said ethylenedicarboxylic acid is fumaric acid.

Claim 8

Method as claimed in claim 1 wherein said ethylenedicarboxylic acid is added in an amount of from about 1 to 4 pounds per barrel.

Claim 9

In a method of drilling wells where in the drilling fluid is passed through the well in contact with an earth formation during the drilling operation in contact with a salt selected from the group consisting of sodium chloride, potassium chloride and mixtures thereof in the formation, the improvement which comprises contacting said earth formation with a fresh water drilling fluid containing clay solids dispersed therein by a clay dispersing agent and containing from about 0.5 to about 6 pounds per barrel of drilling fluid of an ethylenedicarboxylic acid, said ethylenedicarboxylic acid being effective to restore the rheology of said drilling fluid in the presence of any contaminating amounts of salt in the formation, said ethylenedicarboxylic acid being selected from the group consisting of maleic acid, fumaric acid and maleic acid anhydride.

Claim 10

In a method of drilling wells where in the drilling fluid is passed through the well in contact with an earth formation during the drilling operation in contact with a salt selected from the group consisting of sodium chloride, potassium chloride and mixtures thereof in the formation, the improvement which comprises contacting said earth formation with a fresh water drilling fluid containing clay solids dispersed therein by a clay dispersing agent and containing from about 0.5 to about 6 pounds per barrel of drilling fluid of an ethylenedicarboxylic acid, said ethylenedicarboxylic acid being effective to restore the rheology of said drilling fluid in the presence of any contaminating amounts of salt in the formation, said ethylenedicarboxylic acid being selected from the group consisting of maleic acid, fumaric acid and maleic acid anhydride.

Claim 11

IN A METHOD OF DRILLING WELLS WHERE IN THE DRILLING FLUID IS PASSED THROUGH THE WELL IN CONTACT WITH AN EARTH FORMATION DURING THE DRILLING OPERATION IN CONTACT WITH A SALT SELECTED FROM THE GROUP CONSISTING OF SODIUM CHLORIDE, POTASSIUM CHLORIDE AND MIXTURES THEREOF IN THE FORMATION, THE IMPROVEMENT WHICH COMPRISES CONTACTING SAID EARTH FORMATION WITH A FRESH WATER DRILLING FLUID CONTAINING CLAY SOLIDS DISPERSED THEREIN BY A CLAY DISPERSING AGENT AND CONTAINING FROM ABOUT 0.5 TO ABOUT 6 POUNDS PER BARREL OF DRILLING FLUID OF AN ETHYLENEDICARBOXYLIC ACID, SAID ETHYLENEDICARBOXYLIC ACID BEING EFFECTIVE TO RESTORE THE RHEOLOGY OF SAID DRILLING FLUID IN THE PRESENCE OF ANY CONTAMINATING AMO!NTS OF SALT IN THE FORMATION, SAID ETHYLENEDICARBOXYLIC ACID BEING SELECTED FROM THE GROUP CONLEIC ACID ANHYDRIDE,

Claim 12

IN A METHOD OF DRILLING WELLS WHERE IN THE DRILLING FLUID IS PASSED THROUGH THE WELL IN CONTACT WITH AN EARTH FORMATION DURING THE DRILLING OPERATION IN CONTACT WITH A SALT SELECTED FROM THE GROUP CONSISTING OF SODIUM CHLORIDE, POTASSIUM CHLORIDE AND MIXTURES THEREOF IN THE FORMATION, THE IMPROVEMENT WHICH COMPRISES CONTACTING SAID EARTH FORMATION WITH A FRESH WATER DRILLING FLUID CONTAINING CLAY SOLIDS DISPERSED THEREIN BY A CLAY DISPERSING AGENT AND CONTAINING FROM ABOUT 0.5 TO ABOUT 6 POUNDS PER BARREL OF DRILLING FLUID OF AN ETHYLENEDICARBOXYLIC ACID, SAID ETHYLENEDICARBOXYLIC ACID BEING EFFECTIVE TO RESTORE THE RHEOLOGY OF SAID DRILLING FLUID IN THE PRESENCE OF ANY CONTAMINATING AMO!NTS OF SALT IN THE FORMATION, SAID ETHYLENEDICARBOXYLIC ACID BEING SELECTED FROM THE GROUP CONLEIC ACID ANHYDRIDE,

Claim 13

Method as claimed in claim 6 wherein said ethylenedicarboxylic acid is maleic acid.

Claim 14

Method as claimed in claim 6 wherein said ethylenedicarboxylic acid is the anhydride of maleic acid.

Claim 15

Method as claimed in claim 6 wherein said ethylenedicarboxylic acid is added in an amount of from about 1 to 4 pounds per barrel.

Claim 16

A DRILLING FLUID ADDITIVE TO RESTORE THE MUD PROPERTIES OF A FRESH WATER DRILLING FLUID THAT HAS BEEN CONTAMINATED WITH A SALT SELECTED FROM THE GROUP CONSISTING OF SODIUM CHLORIDE, POTASSIUM CHLORIDE AND MIXTURES THEREOF, WHICH CONSISTS OF A MEMBER SELECTED FROM THE GROUP CONSISTING OF MALEIC ACID, MALEIC ANHYDRIDE, FUMARIC ACID, AND A MIXTURE OF MALEIC ACID AND MALEIC ANHYDRIDE.

Claim 17

A DRILLING FLUID ADDITIVE TO RESTORE THE MUD PROPERTIES OF A FRESH WATER DRILLING FLUID THAT HAS BEEN CONTAMINATED WITH A SALT SELECTED FROM THE GROUP CONSISTING OF SODIUM CHLORIDE, POTASSIUM CHLORIDE AND MIXTURES THEREOF, WHICH CONSISTS OF A MEMBER SELECTED FROM THE GROUP CONSISTING OF MALEIC ACID, MALEIC ANHYDRIDE, FUMARIC ACID, AND A MIXTURE OF MALEIC ACID AND MALEIC ANHYDRIDE.