Technological Research And Application For MWD Mud Pulse Signals Recognition

MWD(measurement while drilling)technology has been very common in the current process of oil drilling.In this process,They use various response characteristics of the sensors to get the real-time measurement information.Then They can use computers to process and interpret this logging information to make decisions for drilling real-time guide on the oil and gas reservoir and make the interpretation and evaluation of oil and gas reservoirs.With the geological environment of oil exploration increasing rapidly,the volume of downhole measurement data is growing explosively.Because the getting data speed is not lag behind drilling,They put forward higher requirements for real-time data transmission.Mud pulse signal acts as the carrier of MWD parameters,the recognition accuracy and timeliness of its direct impact on the control precision of drilling and the target rate.Due to all kinds of noise generated during signal transmission,how to detecte useful signal from the strong noise which’s frequency is not fixed,becoming a issue which need to be solved firstly and improved rapidly in mud pulse transmission technology.This paper researched on MWD mud pulse signals,introduced the generation transmission and encoding formats of mud pulse signals,aimed at the noise problems of mud pulse signals,firstly,analysised the noise sources and noise characteristics of the mud pulse signals,based on the study of signal de-noising method,gave the implementation and application of the chebyshev low-pass filter denoising and wavelet denoising,analyzed of the de-noising performance and the scope of the two methods.Secondly,based on the study of mud pulse signal’s Recognition method,we presented a mud pulse signal recognition method based on credibility analysis after extracted the feature attributes and calculated the similarity.Finally,according to the actual needs of drilling,we proposed a solution of Pulse signal recognition prototype system,gave the design ideas and implementation of each module,and completed the initial development of the system.The system combined automatic judgment with human experience to adjust the parameters,which solved the recognition problem of mud pulse signals effectively,meet the requirements for practical engineering.It has laid a good foundation for the follow-up to MWD.