Study On Design And Experiment Of Completion Tool Of Fishbones

At present,the independent research of enhancing oil technology is far behind the foreigner's,so learning foreigner's new technology can accelerate our pace of oil and gas exploration and development.The development of FISHBONES completion stimulation technology is studied,and is considered as simple in principle,reliable in technics,and the performance of stimulation is considerable.Taking cue from FISHBONES technology,aiming at the limitation of the rock and defects of velocity control,based on the rock breaking technology of abrasive water jet,improving the feasibility of FISHBONES technology,in order to develop the domestic unconventional oil and gas field to provide a way to increase production.Four aspects were studied,including early research,theoretical analysis,finite element simulation and experiments,the key technology includes optimization of small diameter pipe,optimization of orbital parameters of steering short,seal between pipe and orbit,integrated design of Fishbone tools,indoor test.The typical mechanical model of small diameter drilling pipe was established firstly,and typical deflection curve equation of pipe was obtained,following suggestions were listed as below: the track with larger curvature radius and larger initial curvature radius should be selected;only considering the deformation,the small diameter of drilling pipe should be selected,and the intermediate value should be selected based on the comprehensive consideration of rock breaking flow;the elastic modulus and material hardening coefficient should take small values.According to the optimization principle,the orbit type is determined,then parameters were calculated,and ultimately the orbit coordinates were determined.The preliminary optimization of geometry of drilling pipe was done by calculating the stress distribution and hydraulic friction loss.The material of pipe was selected by using fuzzy mathematics method,and the result was 0Cr19Ni19 N.Without considering the effect of formation,the process that pipe penetrates out of three kinds of orbits are numerically simulated by transient dynamics,elliptical and circular orbits are suggested,the gap of orbit take larger value,and the pipe with small wall thickness and large diameter should be selected.The process that pipe penetrates out of three kinds of orbits are numerically simulated considering the effect of formation,the results verify the straightening effect of formation.When the reservoir thickness is large,elliptic and circular orbits with small outlet angle should be selected,the recommended angle is 40 degrees.The process that pipe penetrated orbit was tested,the main conclusions are as follow: under the conditions of equal wall thickness,larger outside diameter,smaller bending degree;larger thickness,more serious deformation;with the increase of diameter and thickness,the vertical extension distance is smaller,the horizontal extension distance is larger.The propulsion force variation of pipe is that the force increase before penetration and achieve stationary value after penetration.The propulsion force was different according to the different type of pipe,and the different sealing friction should be designed.According the results of simulation and test,the Fishbone tools suitable for the 5-1/2? were designed.Multiple series of tools can run into well,the orbit outlet angle depends on the reservoir thickness,and the length extending into the formation can achieve 10 m.