Risk assessment of human exposure to radionuclides and heavy metals in oil-based mud samples used for drilling operation.

This study investigates heavy metals and naturally occurring radionuclide materials (NORM) possible presence and pollution rates in oil-based drilling fluids system used to drill an oil and gas well. It also estimates the health risks of the drilling crew due to their exposure to these substances. Measurements from Atomic Absorption Spectrometry (AAS) revealed that, the concentrations of the metals present in the drilling mud samples varied significantly and decreased in the order of Zn > Al > Ni > Pb > Cr > Cu > As > Hg > Cd.

Radiological and toxicity risk exposures of oil based mud: health implication on drilling crew in Niger Delta.

Naturally occurring radioactive materials (NORMs) and the presence of toxic metals in drilling fluids/their additives have raised research interests in recent times owing to the risks associated with the exposure times for drillers of petroleum wells. In this study, two drilling fluids A and B were formulated, while two other Mud Samples C and D were obtained from drilled shale and shale-sand formation zones. All four fluids were collected and analyzed for the presence of radioactive and heavy metals.

Data on shale-water based drilling fluid interaction for drilling operation.

The shale dispersion test (rolling test) is a common procedure that is used to measure the interactions between drilling fluids and shales. The shale rolling test depends on the moisture content of the shale, the shale composition, the viscosity of the test fluid, the rotation speed of the rollers, and the test temperature. The rheological behavior of the test fluid has the strongest influence on test results.

Data for analyzing drilling fluid ability to effectively achieve hole cleaning for high shear and low shear rates.

Rheological models such as Bingham Plastic or Power law models depict fluid behavior with points of the rheological relation which correspond to higher shear rates, but these models are fairly easy to solve for their specific descriptive parameters. Lower rpm (and hence shear rate), could be used to improve the performance and understanding of drilling mud at the lower shear rates prevailing in the wellbore. These data can be utilized in validating these rheological models and the essence of Equivalent Circulating Density (ECD) calculation in analyzing pressure drop in annular hole cleaning.