Monitoring drilling mud

A method of analyzing drilled cuttings in a drilling mud circulating in a borehole being drilled, comprising separating the cuttings from the mud, drying the cuttings, washing a known weight of the dried cuttings in a known volume of solvent to place the sorbed ions into solution and analyzing the solution by ion chromatography for selected positive and negative ions.

A method of analyzing drilled cuttings in a drilling mud circulating in a borehole being drilled, comprising separating the cuttings from the mud, drying the cuttings, washing them to remove the sorbed ions, mixing a known weight of the washed cuttings with a known volume of solution so as to release into the solution the remaining ions still present in the cuttings, analyzing by ion chromatography at least the cation content of the solution, and determining the cation exchange capacity.

A method of analyzing drilled cuttings in a drilling mud wherein the drilled cuttings are dried and then washed free of sorbed ions, a known weight of the washed cuttings is ion exchanged with a replacement cation, in a known volume of solution, the resulting solution containing ions released from the cuttings is analyzed by ion chromatography to identify the cations and measure their concentrations, the total concentration of cations released is calculated from the measured concentrations and then normalized to the dry cuttings weight, and the cation exchange capacity of the drilled cuttings is determined.

A method of analyzing drilled cuttings in a drilling mud wherein the drilled cuttings are dried and then washed free of sorbed ions, a known weight of the washed cuttings is ion exchanged with a replacement cation, in a known volume of solution, the solution is analyzed by ion chromatography before and after ion exchange, the decrease in replacement ion concentration in the solution is ascertained and normalized to dry cuttings weight, and the cation exchange capacity of the drilled cuttings is determined.

A method of testing drilling mud circulating in a borehole being drilled with a drilling rig, which comprises periodically sampling the circulating mud, separating out an aqueous filtrate, analyzing the aqueous filtrate on site by ion chromatography for determining selected positive and negative ion concentrations, storing the ion concentration data and comparing them with already stored data.

In a method analyzing drilled cuttings in a drilling mud circulating in a borehole being drilled, wherein the improvement comprises separating the cuttings from the mud, drying the cuttings, extracting ions from a known weight of the separated dried cuttings into a known volume of a solution containing a salt of a replacement cation, analyzing the resulting solution by ion chromatography, determining total concentrations of cations and anions released from the cuttings into the solution and determining the cation exchange capacity of the drilled cuttings from the difference between the total cation and anion concentrations.