Experiment And Numerical Simulation Study On The Movement Of Cuttings In Inclined And Horizontal Sections

With the increase tension of global energy shortage,the exploration and development of oil and gas has been entered into a new phase.And more and more complex structure well technology,such as highly deviated well,extended reach well and horizontal well,has been extensively applied.During the process of drilling highly deviated well,extended reach well and horizontal well,cutting,generated by the drilling bit,sit on the lower of well and form into cuttings bed because of the effect of its own gravity and the block of drilling pipe.If the cuttings bed cannot be clean and control,it will cause drilling pipe torque and friction increased,lead complex accident in the well and affect the life of drilling tool and the safety of drilling.On the other hand,it will affect the increase of drilling pressure and impede the decentralization of test tools and logging tools,and decrease the rate of work success.Aiming at cuttings migration questions in highly deviated well,extended reach well and horizontal well,the main of this article involves the cuttings migration in deviated well and horizontal well.In order to research the cuttings migration of deviated well and horizontal well,an ocean of material has been consulted to locate the movement and distribution of cuttings in deviated well and horizontal well.Mainly works of this article relate to follows:(1)The process that micro and macro analyzes the mechanism of drilling fluid carrying cuttings in deviated well and horizontal well can provide the theoretical basis for testing and numerical analysis.(2)A visual test bench is built to simulate deviated well and horizontal well.On the condition of different parameters,such as flow of drilling fluid,viscosity of drilling fluid,diameter of cuttings,rotational speeds of pipe and eccentricity of drilling pipe,a series test has been done.From the tests,we can conclude the evolution law of cuttings in deviated well and horizontal well,the start velocity of cuttings in different parameters,the migration velocity of cuttings bed and the sedimentation distance of cuttings.Finally,we can conclude the critical flow from starting velocity of cuttings.(3)A 3D model should be established and solid-liquid two phase flow model should be analyzed by FLUENT.And the job is using the conclusion of testing to prove the feasibility of a simulation model.(4)On the base of the numerical simulation model and the parameters of the drilling site,the movement and distribution law of cuttings in deviated well and horizontal well should be concluded and the influence law of difference parameters also can be concluded.By the same time,we can conclude the best parameter for migration cuttings.This article is combining the test and numerical analysis to locate the movement and distribution law of cuttings in deviated well and horizontal well.And the critical parameters can be reached from the conclusion.In a word,all of the conclusions can make signification to clean the drilling hole in deviated well and horizontal well.