Engineering evaluation of polymer-based drilling fluids for application in Missouri shale

Polymer based drilling fluids have emerged as attractive alternatives to conventional mineral-based slurries for stabilizing boreholes during geotechnical drilling and trenching applications. A series of tests has been conducted in the laboratory to evaluate the behavior of moderately expansive shale specimens upon interaction with a variety of commercially available Partially Hydrolyzed Poly Acrylamide (PHPA) polymer slurries. The series included drum slake, jar slake, linear swell and bulk hardness testing for specimens obtained by coring three diversified Missouri shale formations and allowed to interact with emulsified and granular polymer slurries. Slurries were prepared at different concentrations to evaluate the associated impact on performance. Viscosity was identified as an important parameter affecting the performance of the polymer slurries in terms of concentration and time.; A comparative study has been conducted to evaluate the relative performance of polymer slurries over potable tap water. Indices used to quantify slurry performance in terms of swelling, slaking and hardness are shown to be relatively insensitive to slurry manufacturer or type but significantly sensitive to concentration and immersion time. (Abstract shortened by UMI.)...