Study On The Regulation Method Of High Density Drilling Fluid Rheology Based On EDLVO Theory

High density drilling fluid often falls into aggravation-thickening-reducing adhesion-aggravating agent sedimentation-density decline-again aggravating the vicious cycle.Solid phase content includes weighting agent and drilling cuttings have great influence on rheological properties.In the drilling fluid system,there exists the interaction between particles,resulting in the problem of the rheological degeneration of drilling fluid.In view of the drilling fluid system,the same particle interactions and the different particle interactions that can draw lessons from DLVO theory and EDLVO theory application in the field of colloid system such as mineral flotation,high temperature and high pressure of drilling fluid system is derived to theory of various parameters.The DLVO theory and EDLVO theory shows that the total effect between colloidal particles and potential energy and the distance between the particle size,shape,particle,particle surface potential,electrolyte concentration,molecular weight,the thickness of the adsorption macromolecular flotation agent,pulp temperature and other factors.Using DLVO theory and EDLVO theory can better explain the interaction between particles in high density drilling fluid colloidal system.Firstly,the variation trend of different kinds of particle particles in drilling fluid is calculated based on DLVO theory and EDLVO theory.The effects of particle size,dielectric constant,surface potential and contact Angle were studied.According to the experimental data,the EDLVO theory can guide the regulation of high density drilling fluid rheology.Compared with the experimental phenomena,this paper verifies that the laws of DLVO theory and EDLVO theory are consistent,and the formulas are derived according to the actual situation.Using the theoretical derivation to describe the real data of high-temperature high-density drilling fluid system which can not be accurately described in the experiment,the practical application can be obtained in the field of oil field.