| 摘要 |
A method for viscosifying brine systems utilized in oilfield applications comprising: a) preparing a heavy brine system comprising obtaining an aqueous brine system comprising a hydrated polysaccharide and at least one multivalent salt, wherein the density of the aqueous brine system is greater than about 10 pounds per gallon (ppg), and adding an effective amount of an alkaline agent, thereby increasing the viscosity of the brine system. Also disclosed are methods for viscosifying brine systems utilized in well servicing applications comprising obtaining an aqueous brine solution comprising at least one multivalent salt, wherein the density of the aqueous brine system is greater than about 10 pounds per gallon (ppg); adding a polysaccharide; adding an effective amount of an acid buffering agent to the brine system to lower the pH of the brine system, whereby the polysaccharide is capable of substantially hydrating into the brine system; and adding an effective amount of an alkaline agent, thereby substantially increasing the viscosity of the brine system. |
| 主权项 |
1. A method for viscosifying brine systems utilized in well servicing applications comprising:
a) obtaining an aqueous brine system comprising a hydrated polysaccharide and at least one multivalent salt, wherein the density of the aqueous brine system is greater than about 10 pounds per gallon (ppg) and wherein the pH of the brine system is less than about 7, wherein the level of the at least one multivalent salt is from about 5 wt % to about 90 wt % based on the weight of the brine system, and b) adding an effective amount of an alkaline agent, thereby increasing the viscosity of the brine system, wherein the alkaline agent is selected from the group consisting of amines, alkali metal glycerophosphates, alkali metal orthophosphates, alkali metal hydroxides, carbonates, alkanolamines, silicates, citrates, phosphates, buffering solutions thereof and mixtures thereof, wherein said alkaline agent is used at a range of from about 0.1% to about 30%; wherein said multivalent salt comprises a calcium salt, a magnesium salt, a formate salt, a ferrous salt, a zinc salt or a mixture thereof; and wherein said polysaccharide comprises a cationic guar. |
