Optical fiber sensing has been applied to surface,marine,and borehole seismic acquisition and joint borehole-surface seis-mic acquisition in the latest years.Surface or marine seismic and VSP seismic exploration could be combined to achieve 3D prospec-ting.Using 3D DAS-VSP data,we could obtain accurate time-depth relationship,interval velocity,deconvolution operator,compen-sation factor of spherical spreading,absorption attenuation factor,anisotropy parameters,and high-resolution structure imaging a-round the well bore;above parameters could be used to enhance 3D well-driven land or marine seismic data processing.In this work we performed 3D DAS-VSP data processing and imaging.The 3D DAS-VSP survey was acquired using a downhole armored optical cable with simultaneous OBN data acquisition in the East China Sea.The routine workflow of 3D DAS-VSP data processing includes geometry definition,preprocessing,first break picking,static correction,amplitude compensation,deconvolution,wave field separation,velocity analysis and modeling,and structure imaging using upgoing waves.A new technique of downgoing multiple re-flection imaging is developed to enlarge the migration aperture and imaging area of upgoing reflected waves and obtain better quali-ty of imaging.Compared with 3D vintage OBC data imaging,3D DAS-VSP downgoing multiple imaging yields better results within a large area around the well bore;OBN and 3D DAS-VSP imaging yields better results for high-resolution structure interpretation and fluid detection.Owing to high efficiency and low cost of joint borehole-marine acquisition,it is possible to accomplish fast 3D DAS-VSP imaging and enhanced well-driven resolution processing of 3D marine seismic data.Besides,3D OBN or OBC data and 3D DAS-VSP data could be processed together for joint borehole-surface or borehole-marine migration to significantly improve the im-aging quality of 3D marine seismic data.

近年来,光纤传感技术已经应用于地面地震数据、海洋地震数据、井中地震数据和井-地联合地震数据的采集,推动了光纤传感技术在地球物理特别是地震数据采集领域的应用.对国内外应用于陆地、海洋和井中的光纤地震数据采集系统进行了简要介绍,重点关注了分布式光纤声波传感(DAS)技术在井中地震数据和井-地联合地震数据的采集、处理和综合解释中的应用.光纤传感技术是一项革命性的新技术,光纤因体积小、不带电、分布式、高密度、多参量、耐高温、高压、全段接收和低成本等特征,必将带来井下、海洋和陆地地球物理技术的一场革命.井中分布式光纤声波传感技术已广泛应用于井中VSP数据采集、水力压裂微地震监测和精准工程监测,可实现油气井全生命周期监测、管理和使用.分布式光纤传感技术在油气资源勘探开发领域的规模化推广应用,已经从井中延伸到陆地和海洋;从井下单分量测量拓展到井下和陆地三分量测量(螺旋形绕制的铠装光缆);从单井单参数测量发展到了多井多参数同步测量,调制解调仪器也从单通道单参数发展到了多通道多参数复合调制解调系统.光纤传感技术应用已经由地震勘探领域延伸至油气藏开发领域,围绕光纤应用的地球物理技术对地下结构的静态刻画和动态永久监测逐步形成光纤油藏地球物理技术的基础.展望未来,分布式三分量光纤声波传感技术将在井中、陆地(沙漠)和海洋中用来替代常规三分量检波器采集高密度全波场三分量地震数据,可实现陆地、海洋和井下的高效率、低成本、高密度三分量地震数据采集.此外,研制开发集分布式光纤声波、温度、应变传感于一体的多分量、多参数、多通道复合调制解调仪器;开展耐高温、高瑞利散射系数、抗氢损和弯曲不敏感特种光纤的研制与批量生产;三分量分布式光纤声波(地震波)传感数据采集系统的研制;高密度分布式三分量光纤地震数据处理软件的开发;井-地三分量联采地震数据的联合偏移成像方法研究;套管外铠装光缆定位定向技术与设备研发和与之配套的定向射孔光缆避射技术的发展;人工智能技术在光纤传感领域的推广应用等,必将推动光纤地球物理技术的创新性发展,实现对整个油气田储层的光纤智能油藏感知、描述、模拟和监测,智能优化开发方案和生产制度,在未来智慧油气田的建设中发挥重要的技术支撑作用.

设计了一种超灵敏分布式声波传感地震仪(uDAS(R)),该仪器以高性能相敏型光时域反射仪为基本构架,利用多频和随机光纤激光放大技术,结合干涉解调方法,实现了瑞利散射光信号相位的精确解调,可用于外界声波/振动信号的高精度拾取.实验结果表明,uDAS(R)在1～500 Hz内噪声底达4.5pε√Hz,同时具有线性幅度响应、长距离工作等特征.与电子检波器进行对比测试,二者的记录波形高度一致.uDAS(R)已初步应用于井中地震监测、微测井等勘探作业,获得了高质量的生产资料.此外,uDAS(R)在长期动态监测、管线监测等油气勘探与开发等业务中具有巨大的应用前景.

针对油气藏评价、油气田开发与油气藏生产阶段提出的如何发现残余油和剩余油,如何提高采收率等问题,应用大规模布设的分布式传感光纤,采集井中地震数据,实时收集油气藏储层参数与油气井动态生产数据,进行智能化处理,实现油气藏智能描述、模拟和监测,优化调整油气藏的开发方案和发现剩余油气资源,最终达到提高油气藏采收率的终极目标.基于分布式光纤传感的油藏地球物理技术,将能够直接感知油气藏储层和油气生产井下声波、温度、压力、应变、流体类型等参数的铠装传感光缆布设到沿井孔或油气藏储层内水平井中,实现对整个油气藏的智能描述和监测.近几年中国石油集团东方地球物理勘探有限责任公司主导创新发展了基于分布式光纤声波传感技术的uDAS?地震仪及其配套的井中地震数据采集装备,大力推动光纤井中地震技术、光纤井中—地面联合立体勘探技术、水力压裂光纤微地震及精准储层改造工程监测技术、光纤井下长期动态监测技术在国内大部分油田的规模化推广应用,促进并引领了油藏地球物理光纤智能技术的跨越式创新发展.

A 3D surface seismic data acquisition project was conducted simultaneously with 3D DAS-VSP data acquisition in one well in Jilin Oilfield of Northen China. The 3D surface seismic data acquisition project covered an area of 75 km2, and one borehole (DS32-3) and an armoured optical cable with high temperature single mode fiber were used to acquire the 3D DAS-VSP data simultaneously when the crew was acquiring the 3D surface seismic data. The simultaneously acquired 3D DAS-VSP data were used to extract formation velocity, deconvolution operator, absorption, attenuation (Q value), anisotropy parameters (η, δ, ε) as wel as enhanced the surface seismic data processing including velocity model calibration and modification, static correction, deconvolution, demultiple processing, high frequency restoration, anisotropic migration, and Q-compensation or Q-migration. In this project, anisotropic migration, Q-migration was conducted with the anisotropy parameters (η, δ, ε) data volume and enhanced Q-field data volume obtained from the joint inversion of both the near surface 3D Q-field data volume from uphole data and the mid-deep layer Q-field data volume from all available VSP data in the 3D surface seismic surveey area. The anosotropic migration and Q-migration results show much sharper and focussed faults and and clearer subsutface structure.

分布式光纤声波传感技术(distributed acoustic sensing,DAS)是利用光纤本身作为传感器进行信号采集的一项新兴技术,在国外井中地震勘探的应用发展迅速.为了验证DAS在井中地震勘探应用的适用性,结合DAS在井中地震采集应用实例,简述了DAS技术原理及其在井中地震勘探的实施方法,对比了DAS与常规检波器、可控震源与炸药震源不同激发方式、套管内与套管外不同布设方式的采集资料;以可控震源采集资料为例分析了DAS与常规检波器采集资料直达波振幅衰减规律、不同入射角直达波振幅响应、频谱、子波波形的差异;指出了DAS与常规检波器Z分量采集资料具有较好的一致性,可以部分替代常规检波器Z分量的采集工作;通过对比套管内悬置和套管外水泥固井两种不同光纤布设方式采集资料的直达波振幅响应,认为固井光缆具有与地层更好的耦合效果,同时不易受到井筒内因素的干扰.随着DAS技术的不断进步,凭借其高密度、全井段和高效施工等优点,DAS的应用将逐步拓展到石油勘探的更多领域.

PreviousNext No AccessBeijing 2014 International Geophysical Conference & Exposition, Beijing, China, 21-24 April 2014Affect of the velocity accuracy using Reverse-Time Migration method for Walkaway-VSP acquisitionAuthors: Junjun Wu*Yanpeng LiYuanzhong ChenCongwei LiuFei LiJunjun Wu*BGP Inc., CNPCSearch for more papers by this author, Yanpeng LiBGP Inc., CNPCSearch for more papers by this author, Yuanzhong ChenBGP Inc., CNPCSearch for more papers by this author, Congwei LiuBGP Inc., CNPCSearch for more papers by this author, and Fei LiBGP Inc., CNPCSearch for more papers by this authorhttps://doi.org/10.1190/IGCBeijing2014-335 SectionsAboutPDF/ePub ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinked InRedditEmail Abstract Reverse-time migration technique (RTM), which based on two-way wave equation calculation, has the ability to deal with strong stratum velocity variation. In recent years, this technique has drawn a lot of attention in the industry, and has been widely used in the 3D seismic processing. Conventional Walkaway-VSP imaging method(i.e. VSPCDP technology) can just imaging nearly horizontal layerd stratum, hardly imaging complex structures. Kirchhoff integral migration usually draws arcs in the edges of image when using sparse Walkaway-VSP traces. Wave equation migration can get better imaging result using accurate velocity model. Therefore, the velocity accrucay analysis of Walkaway-VSP RTM based on two-way wave equation is particularly important. In this paper, we carried out initial velocity model demonstration with geologic model for an oilfield in Western China, studied the imaging ability under sevel different velocity model. Finally a field case was imaged, and achieved good result. Keywords: reverse time migration, RTM, VSP, KirchhoffPermalink: https://doi.org/10.1190/IGCBeijing2014-335FiguresReferencesRelatedDetails Beijing 2014 International Geophysical Conference & Exposition, Beijing, China, 21-24 April 2014ISSN (online):2159-6832Copyright: 2014 Pages: 1360 publication data© 2014 Published in electronic format with permission by the Society of Exploration Geophysicists and Chinese Petroleum SocietyPublisher:Society of Exploration Geophysicists HistoryPublished: 24 Apr 2014 CITATION INFORMATION Junjun Wu*, Yanpeng Li, Yuanzhong Chen, Congwei Liu, and Fei Li, (2014), "Affect of the velocity accuracy using Reverse-Time Migration method for Walkaway-VSP acquisition," SEG Global Meeting Abstracts : 1326-1329. https://doi.org/10.1190/IGCBeijing2014-335 Plain-Language Summary Keywordsreverse time migrationRTMVSPKirchhoffPDF DownloadLoading ...

PreviousNext No AccessBeijing 2014 International Geophysical Conference & Exposition, Beijing, China, 21-24 April 2014Velocity sensitivity analysis of Reverse-Time Migration using Walkaway-VSP acquisition modeAuthors: Wu Junjun*Li YanpengChen YuanzhongLiu CongweiZhang XunWu Junjun*BGP, CNPCSearch for more papers by this author, Li YanpengBGP, CNPCSearch for more papers by this author, Chen YuanzhongBGP, CNPCSearch for more papers by this author, Liu CongweiBGP, CNPCSearch for more papers by this author, and Zhang XunBGP, CNPCSearch for more papers by this authorhttps://doi.org/10.1190/IGCBeijing2014-326 SectionsAboutPDF/ePub ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinked InRedditEmail Abstract Reverse-time migration technique (RTM), which based on two-way wave equation calculation, has the ability to deal with strong stratum velocity variation. In recent years, this technique has drawn a lot of attention in the industry, and has been widely used in the 3D seismic processing. Conventional Walkaway-VSP imaging method (i.e. VSPCDP technology) can just imaging nearly horizontal layerd stratum, hardly imaging complex structures. Kirchhoff integral migration usually draws arcs in the edges of image when using sparse Walkaway-VSP traces. Wave equation migration can get better imaging result using accurate velocity model. Therefore, the velocity sensitivity analysis of Walkaway-VSP RTM based on two-way wave equation is particularly important. In this paper, we carried out initial velocity model demonstration with geologic model for an oilfield in Western China, studied the imaging ability under sevel different velocity model. Keywords: RTM, reverse time migration, finite difference, walkway VSPPermalink: https://doi.org/10.1190/IGCBeijing2014-326FiguresReferencesRelatedDetails Beijing 2014 International Geophysical Conference & Exposition, Beijing, China, 21-24 April 2014ISSN (online):2159-6832Copyright: 2014 Pages: 1360 publication data© 2014 Published in electronic format with permission by the Society of Exploration Geophysicists and Chinese Petroleum SocietyPublisher:Society of Exploration Geophysicists HistoryPublished Online: 24 Apr 2014 CITATION INFORMATION Wu Junjun*, Li Yanpeng, Chen Yuanzhong, Liu Congwei, and Zhang Xun, (2014), "Velocity sensitivity analysis of Reverse-Time Migration using Walkaway-VSP acquisition mode," SEG Global Meeting Abstracts : 1292-1295. https://doi.org/10.1190/IGCBeijing2014-326 Plain-Language Summary KeywordsRTMreverse time migrationfinite differencewalkway VSPPDF DownloadLoading ...