Simulation Analysis Of The Working Performance Of The Sealing Mechanism Of Y443 Packer

With the rapid increasing of the oil consumption in the world,horizontal well drilling technology maturing and the profound research on the low permeability oil and gas reservoirs,using down-hole operation technology such as horizontal well staged fracturing to develop the low permeability,low permeability and tight oil and gas reservoirs effectively had become consensus at home and abroad.As the key tools of down-hole operation at staged fracturing,the sealed performance packer directly effects on the construction.The packer's sealing Function mainly depends on the sealing mechanism,which composed of lots of objects like rubber barrel,spacer ring back ring,and other things.Due to the differences of the geological conditions in the oil field,the hole size and regularity,The seal failure of sealing mechanism occurs frequently.This paper based on the sealing mechanism of Y443 packer,as a new product used at an oil field block,to do the performance simulation analysis at setting stage.The results of this thesis provided optimized direction for product designers.(1)The stress-strain experiment of three kinds of rubber barrel materials were carried out,and simulated constitutive model by ABAQUS software,a precise constitutive model of each material was developed at last.studied the quasi static model of non-axisymmetric sealing mechanism study by constitutive model obtained found that:When we choosing displacement loading,and loading speed 1.6m/s,the quasi-static response of the model is good.And specifies K as their sealing performance criteria,which is the product of glue tube effective contact pressure and the effective contact length.(2)Based on the quasi-static analysis model of sealing mechanism,the sealing performance comparison and analysis of E65,A70,B75 rubber tube in three kinds of sealing clearance,five kinds of setting pressure were carried out.All the results showed that:The E65's sealing performance coefficient K value is the largest.But it is easy to damage because of its low strength.The K value of B75 is slightly smaller,and it has high strength.The K value of E65 is least.So,B75 is the final optimized results.(3)The impact analysis of the sealing performance of the rubber tube under five possible setting of clearance when it applied was carried out.Found that two big gap is not suitable for setting,and the other three results reflected that:The K value of the rubber tube increases with the increase of seal clearance and the maximum Mises of rubber tube stress changed little under the same setting pressure;The K value reduces with the increase of the sealing gap but the maximum Mises of rubber tube stress increases under the same compression ratio.The analysis of sealing performance of the rubber tube influenced by the friction coefficient in 0.2-0.7 between the rubber tube and wall were carried out at the same time.The results showed that:The K value reduces with the increase of the friction coefficient and the maximum Mises of rubber tube stress increases under the same setting pressure;The K value increases with the increase of the friction coefficient and the maximum Mises of rubber tube stress increases under the same compression ratio.(4)The optimization analysis of the rubber tube,inner bushing of the packer's sealing mechanism were carried out.Found that:When the inner lining is arranged in the inner of the rubber tube,the inner bush can increase the K value when the rubber tube was not segmented.It can further improve the value of K when the original inner lining was changed into isosceles trapezoid structure.It found that the sealing performance is the best when ?=55° through the optimization of ? which is the trapezoidal corner.(5)The finite element analysis is carried out on the three kinds of structures,which are E,F,G.the rubber tube E has convex.The rubber F has no convex and the end is covered by a spacer ring.The rubber G directs contact with the back ring.The results showed that the K values of the three kinds of rubber tubes were sorted as F>E>G.Through the optimization analysis of ?,the end cone angle of the rubber F,found that:The sealing performance parameter of rubber tube is the biggest when ?=20°.When the cross section of the original back ring was improved into isosceles trapezoid,through the finite element analysis was performed to find that:The improved back ring can reduce the amount of the 20.37%shoulder extrusion value of the rubber tube,and the K value of the rubber tube is also increased.In this thesis,the Influence law of sealing performance of rubber cylinder by the seal clearance,the friction coefficient between the rubber tube and wall under different loading ways was revealed.And the structure of rubber tube ends,inner liner,and moveable back ring is optimizing designed,this can make a reference to packer optimization design.Moreover,the quasi-static analysis modeling method can make some suggestion for other complex packer's finite element analysis.Therefore,the results of this study can make an important contribution for packer design and reduce development costs.