Different model approaches with residual errors to predict the short and long-terms fluid loss and rheological properties of clay bentonite modified with nano-montmorillonite

In this study, the percentage of bentonite in the WBM was ranged from 2%-8% as a percentage of the weight of water. The percentage of clay Nanopowder Montmorillonite (NC) was ranged between 0% and 1% by mass of drilling mud. The tests were performed under various temperature conditions ranged between 25 degrees C and 85 degrees C. From the lab studies and numerical examinations, the electrical resistivity (ER) was identified as a sensing property of the WBM so that the rheological properties can be estimated during the construction. The additional 1% NC reduced the ER of the WBM by 15% to 36% depending on the composition of the drilling fluid and the temperature of testing. The nanoclay modification increased the yield stress (yield point) and shear stress limit tolerance of the WBMs measured using the Vipulanandan rheological model by 32% to 60%, and the outcome of the model prediction was related with Vocadlo model. The laboratory HPHT fluid loss tests were conducted on the drilling fluids based bentonite modified with NC using API standard test up to 420 minutes until the end of the fluid loss. Zero fluid loss was obtained when 8% of bentonite drilling mud modified with 1% of NC at 25 degrees C. The Vipulanandan fluid loss model predicted the short- and long-term fluid loss and the upper limit of fluid losses very well.

Automated summary

This study found that the addition of 1% NC nanoclay modification reduced the electrical resistivity of water-based mud and increased the yield stress and shear stress limit tolerance. In addition, using the Vipulanandan fluid loss model, it was able to accurately predict fluid loss in the drilling fluids.