Design And Feasibility Study Of Perforated Drill Pipe For Inflatable Drilling

Underbalanced drilling allows drilling fluid and other fluids not to enter the production layer,reducing reservoir pollution,thereby increasing oil and gas production.In addition,underbalanced drilling can reduce the pressure of the hydrostatic column in the wellbore and reduce the leakage of the well leakage,which can effectively reduce the pressure effect of the drilling fluid and improve the drilling speed.Therefore,the underbalanced drilling has great advantages and potential development.In the category of inflated underbalanced drilling,the drilling fluid inflated drilling can not effectively transmit the water power,it will lead to the underground motor fatigue.On the other hand parasitic tube gas injection due to high inflation point,inflatable large,leading to difficult migration of cuttings,the next parasitic pipe construction problems and other issues.Under the condition of fully understanding the merits and demerits of the drilling wells and the existing driller manufacturing capacity,the drilling hole with 5-in emphasis is put forward.In the body to wear two or more holes,and the male button deduction of the two steps to seal,so that the gas path through the male and female deduction is still smooth,to ensure that the drilling fluid and gas have different pressure system.Based on the design of the drilling tool,this paper establishes the 3D model for the rigid male button of the drilling tool and discusses the double step sealing problem.Combined with the knowledge of materials and finite element,and the use of ANSYS software on the body of the perforated form of the optimization study,and male and female buckle joint static analysis,discussed the analysis results,proved that the design of this drill pipe can be used to achieve the strength conditions.In this paper,using the results of SN curve and strength analysis of drilling materials,the fatigue life of the drill pipe joint under specific cyclic stress condition is calculated by Designlife software,which indicates that the design of the drill pipe can achieve the fatigue condition.In this paper,the gas-liquid two-phase flow model and the Mathcad software are used to simulate the calculation of a well,and the amount of gas in the drilling fluid is limited under the condition that the cuttings can be transported.The relationship shows how to use perforated drill pipe for inflated underbalanced drilling.The gas injection ring is designed to optimize the design of the gas injection ring.The reason of the design is explained by the mechanical analysis and empirical formula of bubble morphology.And check the perforated drill pipe design when the hole can be set by the ventilation.This paper completes the analysis of the use condition of the perforated drill pipe,the establishment of the 3D model,the strength and fatigue analysis,and the analysis of the use of the perforated drill pipe and completes the optimization of the gas injection port,proving that the drilling tool is feasible and designed and manufactured for the drill pipe and the use of a theoretical reference.