New Eco-friendly Microemulsion-based Drilling Fluid
Environmentally friendly drilling fluids were formulated from microemulsion systems by using aqueous phase(water-glycerol solution 1∶1),oil phase(pine vegetable oil),and different nonionic surfactants(Tween 80,nonylphenol ethoxylates 100 and 150).Two clays(PA and 20A)were used to formulate the fluids with the addition of viscosity builder(xanthan gum),weighting agent(plain),sealing agent(calcite),and dispersant(water).The properties of the formulated drilling fluids such as mass loss,filtration loss,and rheological properties were analyzed.The results showed that the shear stress-shear rate data of the fluids conformed to the Herschel-Bulkley rheological model with R2=0.99.The lowest consistency index was obtained for the fluids formulated with PA,between 0.37 and 0.61,and therefore,the lowest force required to start the fluids was obtained.Thermogravimetric analysis showed that the resulting microemulsified drilling fluid could work at up to 100℃,making it possible to apply it in wells with high temperatures.The filtration loss was 2.4～4.0 mL,the maximum thickness of the filter cake was 0.8 mm,and the permeability was low(0.0173 mD).The analysis results showed that the lubricity was also improved when the microemulsion system was added.Overall,the environmentally friendly microemulsion drilling fluid had good deflation effect,good rheology,and low API filtration loss,and could be used in oil well drilling operations.
万方数据
维普
