双约束变换时窗统计能量比地震波初至拾取方法

A first arrival pickup method of micro-seismic event based on statistic energy ratio using varied time window with double constraints

地震数据的初至拾取是地震勘探中数据预处理的关键步骤。在非常规油气藏的开发过程中,地面微地震监测技术被广泛应用,由于微地震数据信噪比普遍较低,因此很难得到较为准确的初至拾取结果。针对地震数据的初至拾取精度和算法的抗噪性能,在变换时窗统计能量比法的基础上进行改进,应用统计学规律的同时设置阈值门槛R,求取可信度高的优势道,结合拾取范围约束Z以及多种拾取策略逐道计算,最终实现地震记录的初至拾取。利用该方法对松辽盆地某工区三维地震数据及某地区水平井水力压裂地面微地震监测数据进行初至拾取,取得到了较好的拾取效果,验证了该方法的实用性。

The first arrival of seismic data is a key step of data preprocessing in seismic exploration.In the development of unconventional oil and gas reservoirs,surface microseismic monitoring technology is widely used.The focus of the work is to obtain the source location information generated by hydraulic fracturing,that is,the location of the microseismic source.For the microseismic source location,the initial picking of microseismic events is a key step,and the accuracy of the picking results directly affects the positioning accuracy of the microseismic events and the interpretation of the final results.However,in the actual seismic data,the signal-to-noise ratio of microseismic data is generally low,and it is difficult to obtain more accurate first arrival results.At present,the picking up of the first arrival wave of the microseismic is mainly divided into two methods:manual picking and computer automatic picking.The manual picking has the characteristics of high accuracy,but the workload is large,time- consuming and laborious.Aimed at picking accuracy of the first-arrival wave of seismic data and the anti-noise performance of the method,this paper makes improvement on the basis of the statistical energy ratio method of transforming time window,and sets the threshold value R while applying statistical law to obtain the superiority of high credibility.Combined with the value of picking range constraint Z and a variety of picking strategies,the first-arrival wave pick-up of the seismic record is finally achieved.The method was used to pick up the3D seismic data of a work area in Songliao Basin and the hydraulic fracturing ground microseismic monitoring data of a horizontal well in Songliao Basin.The picking effect was obtained and the practicability of the method was verified.In summary,the method has achieved good pickup results in both the theoretical data of different signal-to-noise ratios and the application of actual data,and has strong anti-noise performance.