Patent ID: 8596380

Claim:
A measurement system configured to assess hydrogen sulfide (H2S) concentration within drilling fluid, the drilling fluid being part of a drilling system configured to drill a wellbore in the Earth, the measurement system comprising: a) an intermittent assessment subsystem configured to quantitatively determine hydrogen sulfide concentration in the drilling fluid, wherein such determining is carried out on an intermittent basis; and b) an ongoing assessment subsystem configured to qualitatively assess changes in hydrogen sulfide concentration in the drilling fluid in situ and on an ongoing basis, the ongoing assessment subsystem comprising: i) electrical conductors in direct contact with drilling fluid within the drilling system; ii) a signal generator configured to apply an electric potential between the electrical conductors such that an electric current runs between the electrical conductors through the drilling fluid; and iii) a processor configured to measure an electrical property of the drilling fluid based on a parameter of the electric current, wherein values for the electrical property are a function of hydrogen sulfide concentration in the drilling fluid, and to assess changes in hydrogen sulfide concentration in the drilling fluid in situ based changes in the values for the electrical property over time, and wherein the ongoing assessment of changes in hydrogen sulfide concentration by the ongoing assessment subsystem is calibrated with the quantitative determination of hydrogen sulfide concentration provided intermittently by the intermittent assessment subsystem, so as to provide for a qualitative, in situ, continuous monitoring of hydrogen sulfide in the drilling fluid.