An increasing area of concern for offshore drilling practices is the environmental impact of discharged drilled cuttings contaminated with drilling fluids. The standard retort anal-ysis is of limited accuracy and chemical specificity. Anticipating future requirements for a more complete accounting of mud chemicals discharged to the environment, we present here results for chemical monitoring using a modern comprehensive chemical analysis technique, Fourier transform infrared (FT-IR) spectrometry. A description is given of sampling methods found to be practical and the main calibration requirements are discussed. The techniques developed in the course of this work give a good mineralogical breakdown of mud solids (commercial and drilled solids) in addition to the environmentally relevant measurements relating to mud on cuttings. The possibility of using the new technique for the rigsite monitoring of drilling cuttings is demonstrated. Cuttings samples simultaneously from the flow line, shaker screen, desilter and mud cleaner were analysed. It is found that mud polymers and other organic additives can be measured with sufficient accuracy to measure the removal of mud products by discharged cuttings. The technique is also applicable to quantify the losses of oil-based mud on cuttings. Field testing has shown that the instrumentation used is sufficiently robust and simple to use for rig-site application.

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