High Transient Algorithm And Experimental Research On Cuttings Bed Height In Horizontal Wells

With the gradual reduction of domestic oil and gas reserves,China’s oil and gas exploration is developing towards resource fields such as shale oil and natural gas hydrates.In the drilling process,with the continuous extension of horizontal and extended reach well technologies,rock debris accumulation always occurs underground,forming a rock debris bed that affects drilling.regarding the research direction of cuttings bed migration in horizontal wells,many domestic and foreign scholars,under the law of rock debris migration,by adjusting various influencing factors to improve wellbore cleaning efficiency,therefore,studying the height and migration patterns of rock debris beds is of great significance for engineering applications.This article mainly focuses on the transient algorithm for the height of horizontal well cuttings bed,based on the solid-liquid momentum equation and continuity equation,consider the solid-liquid phases that form the cuttings bed section as a whole.In the calculation model,Introduce conditions such as drilling fluid rheology,drill pipe speed,rock debris particle size,and well inclination angle,using projection and discretization methods to solve the model,calculate the pressure poisson equation in matrix form,using a new iterative method to improve computational efficiency and accuracy,establish a model for calculating the transient height of rock debris bed and the migration velocity of rock debris,then,the established model is used to solve the height of the rock debris bed and the migration velocity of rock debris,after analyzing and changing various conditions,the calculated height of the rock debris bed and the results of rock debris transport,finally,the cuttings migration experiment of horizontal well is carried out through indoor flow loop equipment,and the control variates is used to change different conditions,complete the experiment,observe and record the movement speed of the rock debris bed and the changes in the height of the rock debris bed,summarize the experimental data and validate it with the predicted results of the proposed model.The research results indicate that,drill pipe speed,wellbore inclination angle,displacement,drilling fluid consistency coefficient,flowability index,drilling fluid density,rock debris particle size,drilling speed(volume concentration)all have a significant impact on the height of the horizontal well cuttings bed and the migration of cuttings,at the same time,the computational model designed in this article has been experimentally validated,Prove the success of the model establishment.