Research And Simulation On The Theory Of Avoid The Collision Between Casing Well

With the rapid development of cluster drilling technology,drilling and well collision accidents often occur in drilling process.Therefore,developing a set of borehole anti collision device is urgently needed by oil drilling.Compared with other electromagnetic collision avoidance theory,the theory of electromagnetic collision avoidance based on the theory of interwell electromagnetic distance measurement has the advantages of high accuracy,strong timeliness and high reliability.It is a kind of anti collision technique which can be used as the key research in the future.The theory of anti collision of casing well current method studied in this paper is one kind of electromagnetic anti collision for its physical quantity.The research process is as follows: firstly,based on the existing traditional electromagnetic anti-collision theory were analyzed and compared,using patent US796228 the content of casing current method anti detection device and process touch technology;secondly,the theoretical derivation based on the basic electromagnetic theory,the application of equivalent resistance method and model transformation method to establish a set of transmitter and receiver are located in the new drilling casing current anti-collision theory.This paper applies the method of theoretical derivation and numerical simulation to establish the theory of collision prevention for cased hole current method.When the current distribution on the drill collar is solved,the line transmission model of the current on the drill collar is derived from the basic electromagnetic theory,and then the COMSOL software is used to simulate the current on the drill collar and modify the derived model.When calculating the current on the casing of the target well,the current on the casing of the target well is derived by means of equivalent resistance and resistance shunt.Next,a brief exploration and introduction is made on the theory of collision avoidance in heterogeneous formations,in which the method of application is consistent with that in homogeneous formations.At last,the method of computer numerical simulation is used to obtain the current and the distribution of the magnetic field on the casing of the target well under certain conditions,and the obtained theory is expressed,and the conclusion is obtained.Compared with the traditional electromagnetic anticollision technology,due to the application of this method to measure between the target and the distance between the new casing drilling is still at the exploratory stage,casing current method based on the anti-collision technology and its theory is not yet mature,some formulas are based on experience or experiments,so the precision is low.But this anti-collision technology has a very broad application prospect.On the one hand,it can install relevant instruments only in new drilling,which greatly reduces the time and money required for measurement,and will not cause too much interference to the production of the target well.On the other hand,this method avoids the interference of the magnetic field generated by the new self drilling current and the geomagnetic interference,and the design is very ingenious.It is believed that after a period of research,it will be widely used in the field of casing well detection and electromagnetic collision prevention in the future.