1.目的 随着四川盆地油气勘探目标向隐蔽性地质目标转移,对地震资料保真度和分辨率提出更高要求.地震检波器是油气地震勘探关键设备之一,直接关系到地震资料品质的优劣.理想条件下,检波器接收到的信号反映了表土真实的机械振动情况,但实际的地震波接收过程受检波器自身性能及检波器表土耦合问题的制约,会影响接收到的地震波动力学特征信号.因此,笔者基于外界噪声投射原理、检波器与表土耦合响应影响因子分析,提出了四川盆地地震采集检波器"体耦合"埋置技术.

四川盆地火山岩发育区生储盖组合配置好,油气成藏条件优越.2018年,YT1井获得高产工业气流,证实了该区二叠系火山岩具有较大的油气勘探潜力.但由于以往地震资料的信噪比低、成像精度不高,难以满足火山岩有利相带的精细刻画及井位部署需求.为此,通过高精度三维观测系统设计、井—震联合采集施工、动态激发井深设计、低频检波器接收技术等采集关键技术的应用,目的层地震资料信噪比与分辨率得到大幅提高;并且利用新资料建立了火山岩喷溢相地震识别模式,有效识别了喷溢相与溢流相火山岩的平面分布,推动了四川盆地新区、新领域的天然气勘探进程.

Sichuan Basin is rich in natural gas resources and is the basin with the most potential for natural gas exploration and development in China. The problems of low signal-to-noise ratio and poor imaging quality of seismic data in the eastern high and steep tectonic area of Sichuan basin have brought great challenges to the seismic exploration in this area. The outcrop lithology in this area is mainly limestone. Due to rapid dispersion of seismic wave energy excited in the rigid formations, effective down-transmitting energy of seismic waves is insufficient, resulting in a low signal-to-noise ratio of seismic raw data. Starting from the cavity excitation theory, we select parameters in the cavity excitation method. By reducing the initial pressure of the explosion and prolonging the action time, the conversion rate of excitation energy into effective elastic wave energy is improved, and the signal-to-noise ratio of seismic data in the limestone area is effectively enhanced.

The earth surface in the Sichuan Basin and its periphery is geologically complex, which causes low signal-to-noise ratio of seismic data, poor imaging quality of seismic profiles and great difficulty in data acquisition. In order to ensure high-quality operation of the seismic survey project in the complex surface of the Sichuan Basin, researchers have been working continuously to solve the bottleneck problems in the seismic acquisition technology for complex surface in recent years. In addition, the upgrading of acquisition technology and operation capacity is promoted effectively by means of technical innovation, and a series of key technologies for seismic acquisition are developed. And the following application results of this series of technologies are obtained. First, the optimization design technology of the geometry based on wave equation forward modeling and actual data, combined with prestack migration imaging can show the influence of different acquisition schemes on the prestack imaging effect of complex targets more directly, which makes the seismic acquisition scheme more economic and effective. Second, by extracting landform risks and surface obstacle information intelligently, combined with field fine reconnaissance, landform risk identification and hierarchical evaluation and indoors intelligent optimization of well-shot physical point deployment are conducted, and thus the GIS+ intelligent deployment technology of shot point in complex surface is formed, which effectively reduces the risks of operation. Third, the cavity excitation technology which reduces the initial pressure of explosive pulse and extends the explosive action time of explosives can increase the conversion rate of rock excitation energy into effective elastic wave energy and the reflected energy and improve the quality of seismic single shot data. Fourth, combination of the automatic evaluation technology for field seismic data acquired in mountainous regions and the KL-GMLiveQC1.0 software can improve the evaluation efficiency, reduce the evaluation cost and ensure the high-quality acquisition of seismic data in complex surface. In conclusion, this series of key seismic acquisition technologies greatly improve the signal-to-noise ratio and resolution of seismic data, lay a foundation for fine reservoir prediction, and ensure the continuous important breakthrough of three-dimensional natural gas exploration and development in the gas fields of marine carbonate rock, shale gas, volcanic rock and shallow tight sandstone gas in the Sichuan Basin.

随着GNSS测量技术的发展与应用,其平面坐标和大地高可达到mm级定位精度,GNSS大地高转换为正常高的质量和精度,已更多的取决于获取高程异常值的精度.本文提出了一种综合利用EGM2008地球重力场模型和研究区域适量GNSS/水准控制点,利用"分级移除-克里金空间插值拟合-恢复"法快速准确获取高程异常值并建立了四川盆地Cm级精度的高程异常值库.实践表明:采用上述方法,拟合精度可达到四等水准测量的精度要求,远优于现行石油物探测量行业标准相关要求,为石油物探GNSS测量高程转换提供了低成本、高效率的技术选择方案.

Sichuan Basin is rich in natural gas resources and is the most potential basin for gas exploration and development in China. But there are still many challenges that remained from further breakthroughs due to the low SNR (signal to noise ratio) and poor imaging of seismic data in foothills regions in eastern Sichuan Basin. In this abstract, 3D geometry design method is proposed for complex geological target based on seismic illumination analysis of forward modeling data to effectively guide the design of 3D geometry in this area. With the application of 3D seismic geometry scheme, the SNR of real seismic data has been effectively improved and the seismic imaging results have also been significantly enhanced for high and steep complex structures in Sichuan Basin.

PreviousNext No AccessSEG 2019 Workshop: 2nd SEG Foothill Exploration Workshop, Chengdu, China, 12–14 April 2019Seismic survey design based on visibility analysis: a case study from sichuan complex foothills areaAuthors: Shanzheng HuXiaoBin ZhangPandeng LiuShuQin LiJiangLi ChenChengYi LiJun WuShanzheng HuBGP, CNPCSearch for more papers by this author, XiaoBin ZhangBGP, CNPCSearch for more papers by this author, Pandeng LiuBGP, CNPCSearch for more papers by this author, ShuQin LiBGP, CNPCSearch for more papers by this author, JiangLi ChenBGP, CNPCSearch for more papers by this author, ChengYi LiBGP, CNPCSearch for more papers by this author, and Jun WuBGP, CNPCSearch for more papers by this authorhttps://doi.org/10.1190/FEW2019-03.1 SectionsAboutPDF/ePub ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinked InRedditEmail Abstract It is an enormous challenge for the balance between acquisition cost and data quality. In recent years many methods and tools were developed in seismic survey design to address the increasing complexity of geophysical and geological problems that seismic exploration is faced with. In this paper, we present a methodology of seismic visibility analysis which is applied to 2D target-oriented acquisition design for extracting optimal acquisition parameters. An analysis work flow based on a shot visibility using the full-acquisition aperture is used to guide selection of optimal 2D acquisition parameters. The primary objective of this case study is to evaluate alternative acquisition geometries for imaging a target under an unsatisfactory shot condition. The visibility studies support reasonable offset acquisition geometries to provide imaging uplift for the target under the seismic obscured zone. Keywords: 2D, acquisition, optimizationPermalink: https://doi.org/10.1190/FEW2019-03.1FiguresReferencesRelatedDetails SEG 2019 Workshop: 2nd SEG Foothill Exploration Workshop, Chengdu, China, 12–14 April 2019ISSN (online):2159-6832Copyright: 2019 Pages: 79 publication data© 2019 Published in electronic format with permission by the Society of Exploration GeophysicistsPublisher:Society of Exploration Geophysicists HistoryPublished Online: 28 Aug 2019 CITATION INFORMATION Shanzheng Hu, XiaoBin Zhang, Pandeng Liu, ShuQin Li, JiangLi Chen, ChengYi Li, and Jun Wu, (2019), "Seismic survey design based on visibility analysis: a case study from sichuan complex foothills area," SEG Global Meeting Abstracts : 6-9. https://doi.org/10.1190/FEW2019-03.1 Plain-Language Summary Keywords2DacquisitionoptimizationPDF DownloadLoading ...

PreviousNext No AccessSEG 2019 Workshop: 2nd SEG Foothill Exploration Workshop, Chengdu, China, 12–14 April 2019A case study of joint 3C3D and 3DVSP seismic exploration in carbonate area in Sichuan basinAuthors: Shuqin Li*Xiaoyang WangLiu YangFurong WuShanzheng HuMin LiJiangli ChenLongjiang JingShuqin Li*BGP of CNPCSearch for more papers by this author, Xiaoyang WangBGP of CNPCSearch for more papers by this author, Liu YangBGP of CNPCSearch for more papers by this author, Furong WuBGP of CNPCSearch for more papers by this author, Shanzheng HuBGP of CNPCSearch for more papers by this author, Min LiBGP of CNPCSearch for more papers by this author, Jiangli ChenBGP of CNPCSearch for more papers by this author, and Longjiang JingBGP of CNPCSearch for more papers by this authorhttps://doi.org/10.1190/FEW2019-14.1 SectionsAboutPDF/ePub ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinked InRedditEmail Abstract As a new seismic exploration method combining surface seismic and 3D Vertical Seismic Profiling (VSP) in wells, joint 3D and VSP technique realizes the combination of surface and down-hole seismic acquisition, and can achieve the purpose of synchronous acquisition and synchronous processing, thus improves the imaging accuracy of the exploration area. A joint 3C3D surface seismic and 3DVSP exploration project has been carried out in the carbonate area in Sichuan Basin. The results show that the joint multi-component 3D and VSP technique effectively improved the exploration accuracy in the exploration area. The project realized the synchronous acquisition of 3C3D surface and down hole in mountainous area, and the acquisition cost is reduced by 33.7% compared to separate acquisitions. This project is the first joint 3C3D surface and down-hole acquisition project targeting at the middle-deep carbonate formations in China. Keywords: 3D, VSP, acquisitionPermalink: https://doi.org/10.1190/FEW2019-14.1FiguresReferencesRelatedDetails SEG 2019 Workshop: 2nd SEG Foothill Exploration Workshop, Chengdu, China, 12–14 April 2019ISSN (online):2159-6832Copyright: 2019 Pages: 79 publication data© 2019 Published in electronic format with permission by the Society of Exploration GeophysicistsPublisher:Society of Exploration Geophysicists HistoryPublished Online: 28 Aug 2019 CITATION INFORMATION Shuqin Li*, Xiaoyang Wang, Liu Yang, Furong Wu, Shanzheng Hu, Min Li, Jiangli Chen, and Longjiang Jing, (2019), "A case study of joint 3C3D and 3DVSP seismic exploration in carbonate area in Sichuan basin," SEG Global Meeting Abstracts : 51-54. https://doi.org/10.1190/FEW2019-14.1 Plain-Language Summary Keywords3DVSPacquisitionPDF DownloadLoading ...