Depth Error Analysis Of The Process Of Drilling Wells

In the process of drilling wells, the depth of the hole is one of the important basic datasfor the calculation of formation parameters, and can accurately record the depth of theparameter measuring instrument, will directly affect the collection and analysis of a variety oftest datas,at present we use the method of measuring and calibrating the depth of a well,straightly use both the artificial comprehensive calibration method and instrumentmeasurement design to ensure the accuracy of the depth measurement of the reservoir. But thepractice has proved that due to the deformation of tubing string this method is prone to errorin practice, and sometimes the error is more serious. Therefore, accurate depth of the well is apoint that can not afford to neglect.In the process of operation and production, the drilling string must bear the axial force,pressure of the fluid, temperature of the formation, bending torque,buoyancy of drilling fluid,and the friction between the shaft wall, under the influence of the factors such as the pistoneffect caused by the state, state of axial force effect, expansion effect, temperature effect, drillstring deformation increment caused by the buckling effect state and string gravity condition.Thus the string mechanics analysis is very complicated and very important.The object of this essay is the drilling string. Analyse the working state of the string, setup the model of drilling string increment, the finite element division on drilling strings andprograme and calculate by the VB on the basis of the predecessors’ work. Combing with thefield data,drilling string deformation is calculated in the process of drilling. Through theanalysis of the software at the same time, we can check the strength of pipe string, make theintensity and the deformation analysis more simple and make any depth string deformationcalculation more accurate, which provide accurate positioning reservoir depth and precisionof hole depth.