Research On Recognition Method Of Drill Bit Vibration Signal Under Noise Interference

In the offshore oil and gas field cluster wells development,especially in the original well pattern drilling adjustment wells,making the use of the slot on the platform more dense and compact,wellhead spacing is getting smaller and smaller,this time the risk of collisions between drilling bit and adjacent wells boreholes increases.Drilling or even drilling of adjacent casing will cause drilling accidents.Therefore,anti-collision monitoring during drilling is indispensable.By identifying the vibration signals of the drill bit,it is possible to determine the extent to which the drill bit approaches the risk adjacent wells and timely warning and stopping the drilling before the collision,which is of great significance for safety drilling.This paper investigates the application status of borehole anti-collision technology both at home and abroad and the research status of bit vibration signal processing in anti-collision detection technology.The generation characteristics of vibration wave and the sources and characteristics of interference noise are discussed.By analyzing and comparing the characteristics of collected signals under different working conditions,the characteristic frequency band of the drill bit vibration signal is identified,and the influence of rotational speed and drilling pressure on drill bit vibration signal is further studied.The results show that the characteristic frequency of rock burst vibration signal is about 2300 Hz,and the vibration signal frequency range is stable and does not change with rotational speed and drilling pressure.The speed and drilling pressure only influence the intensity of signal.By studying the propagation characteristics of the vibration signal in the medium,under the experimental conditions adopted in this paper,the vibration signal attenuates when propagating in the rock while the simulated casing amplifies the amplitude of the vibration signal.The independent component analysis is used to process the casing detection signal,and the separation and extraction of bit breaking rock vibration signals under the propagation interference is completed.The results show that the rock breaking vibration signals of drill bits are mainly distributed around 2300 Hz,which is in accordance with the frequency distribution in the drilling process.The signal processing method introduced in this paper can effectively identify and separate the bit vibration signal under noise interference,which has a reference meaning for the signal processing of actual borehole anti-collision monitoring.