LET'S TALK ABOUT MUD,PART 2

摘要

Hello again everyone. I hope you've all been turning to the right since we last chatted. Last time we explored the functions of a drilling fluid, what the drilling fluid does, and talked about the first drilling fluid property-viscosity. The next fluid property to describe the drilling fluid is density, or how much the fluid weighs. The two most common ways to express density are in pounds per gallon (ppg) or specific gravity (Sg). As a reference, water weighs 8.34 ppg or has 1.0 Sg. Anything added to water that has a specific gravity greater than water will increase the density of the mixture. In the world of water well drilling, commercial drilling fluid products-such as bentonite and drilled solids created during drilling-when added to water increase the resulting fluid's density. Bentonite and most drilled solids have an average specific gravity of 2.6 (or 2.6 times heavier than water). When we first add bentonite to water, we see a viscosity increase and we can measure both the viscosity increase and the fluid density increase. From last time, we know to use a Marsh funnel and cup to measure viscosity.