近3年,四川盆地相继在川中古隆起北斜坡上震旦统灯影组二段和四段、下寒武统沧浪铺组一段、二叠系茅口组二段取得勘探突破,继安岳气区发现之后形成了新的万亿立方米级大气区——蓬莱气区。受大型张性走滑断裂、古裂陷槽、台缘带联合控制,蓬莱气区纵向上发育多层系规模化烃源岩、储集层及断控岩性圈闭;良好的"源-储"配置和垂向输导通道促进了多层系油气高效充注;"古隆今斜"的构造演化保证了油气高效汇聚;多层系直接盖层和区域盖层的发育为油气提供了良好的保存条件。得益于成藏要素在时间和空间上的良好配置,蓬莱气区震旦系—二叠系形成了特有的斜坡区深层—超深层、多层系、海相碳酸盐岩立体成藏模式——"立体供烃、立体成储、立体输导、早油晚气、立体成藏"。蓬莱气区多层系天然气勘探突破不仅大大拓宽了四川盆地深层—超深层天然气勘探领域,也证实了在历经多期构造运动后,古隆起斜坡部位的超深、超老地层仍具有形成规模性天然气聚集的潜力,对进一步深化四川盆地超深层天然气勘探具有重要指导意义。

In recent 3 years, breakthroughs have been made in exploration of Member 2 and 4 of Dengying Formation of Upper Sinian in Sichuan Basin, Member 1 of Canglangpu Formation of Lower Cambrian, and Member 2 of Maokou Formation of Permian in the north slope of the central Sichuan paleo-uplift. After the discovery of Anyue gas area, a new large gas area of trillion cubic meters, namely Penglai gas area, has been formed. Under the joint control of large extensional strike-slip faults, paleo-taphrogenic trough and platform margin zones, multi-layer large-scale source rocks, reservoirs and fault-controlled lithologic traps are vertically developed upwards in Penglai gas area; the good source-reservoir configuration and vertical transport pathways promote the efficient filling of multi-layer oil and gas; the tectonic evolution of "ancient uplift and present slope" ensures the efficient accumulation of oil and gas; the development of direct cap rocks and regional cap rocks in the multilayer system provides good conditions for hydrocarbon preservation. Thanks to the good spatio-temporal collocation of accumulation elements, the Sinian-Permian system in Penglai gas area has formed a unique three-dimensional accumulation model of deep, ultra-deep, multi-layer and marine carbonate rocks in the slope area, i.e., "three-dimensional hydrocarbon supply, three-dimensional reservoir formation, three-dimensional transportation, early oil and late gas, three-dimensional accumulation". The breakthrough in the natural gas exploration in multi-layer system of Penglai gas area can not only greatly expand the exploration of deep and ultra-deep natural gas in Sichuan Basin, but also prove that after multi-period tectonic movements, the ultra-deep and ultra-old strata at the slope of the ancient uplift still have the potential to form large-scale natural gas accumulation, which is of great significance for guiding the further exploration of ultra-deep natural gas in Sichuan Basin.

On the basis of the analysis of the current energy situation and oil-gas exploration, the current basic research about reflection seismology involved in petroleum exploration in China were discussed, such as how to explore deep oil-gas fields in large sedimentary basin, topographic interference wave suppression, seismic signal bandspread, direct prediction of oil-gas field and cross- hole seismic tomography. The essential target presented for current oil-gas seismic prospecting basic research is to develop the fourth generation of oil-gas seismic prospecting processing and quantitative interpretation techniques, as well as improve the seismic wave field prestack migration imaging.

在地震勘探过程中,随机噪音是影响地震资料信噪比的主要因素之一,尤其是对能量弱、频率低的深层地震信号。与有规律的线性干扰相比,随机噪音没有固定的视频率和视速度,但在一定的区域范围内,这类干扰又是遵循统计规律的。因此,深入地调查和分析工区内随机噪音的特征及其与施工因素的关系,对于更好地指导野外数据采集具有实际意义。本文结合胜利探区深层试验资料,主要对随机噪音中的环境噪音和次生噪音的特征及其与施工因素的关系进行了定量分析和统计,获得了一点认识,并提出了一些行之有效的压制方法,在实际生产中收到了一定的效果。

针对深层地震信号能量弱、频率低、可描述性差及信噪比低的特点,对深层地震资料的处理方法开展了研究,提出了采用地表一致性振幅处理技术、多域去噪技术、剩余时差校正技术、主能量优化叠加技术等进行精细处理,并且,将地质模型作为一种约束条件引入深层资料处理的整个环节,提高了叠加成象的精度。通过对BH、DY等地区老资料及LFJ地区深层采集资料的精细处理,总结出了一套提高深层资料信噪比,改善资料叠加成像效果的深层资料精细处理流程。

江苏油田村庄密集，水网密布，工农业发达，野外采集资料品质较差。原始单炮记录上噪声类型多，分布广；深层能量弱，高频成分损失严重；深层资料信噪比低，成像困难。针对这些问题，首先对深层噪声进行了压制，保留深层的有效波信息；然后对深层的有效信号进行能量补偿，拓宽目的层频带，进行频率补偿，得到了较好的深层资料信息；最后对浅、中、深层资料进行可变扩展面元叠加，提高了资料的信噪比，在此基础上进行叠前时间偏移，使深层资料的成像质量得到了较大的改善。

There are lots of villagess, rivers, developed industries and agriculture in Jiangsu oilfield,making the acquired seismic data a poor quality. Many kinds of noise distribute widely in original shots. Energy is weak and high frequencies are seriously lost in seismic data of deep layers.So S/N is low and imaging is difficult for deep layers.In order to solve these problems,firstly,the deep noise was depressed and the effective wave preserved. Then,some measures were taken for effective signals of deep layers,including energy compensation,enlargement of target frequency width,frequency compensation.After taking these measures,good deep layer data were achieved.Finally,variable extended bin stacking was carried out on shallow,middle,and deep depths of seismic data,greatly improved S/N ratio.On this basis,prestack time migration is processed and the imaging quality of deep seismic data greatly improved.

地震勘探中的噪声对地震信号产生严重的畸变和干扰，常规的地震去噪方法已经不能满足当前高精度地震勘探的要求。提出了基于Shearlet变换的地震数据去噪方法，Shearlet变换是一种新的多尺度变换方法，具有多方向、多分辨率及最佳稀疏逼近性质，并且计算效率高。Shearlet变换在去除随机噪声的同时能最大程度保留有效信号，有效地提高信噪比。利用Shearlet变换阈值去噪法与其他地震去噪方法分别对不同信噪比的合成地震记录和实际地震记录进行对比，结果表明Shearlet变换具有更强的去噪能力和更高的运算效率。

In seismic exploration, the noise seriously distorts and interferes with seismic signal. Conventional methods of seismic data denoising can no longer meet the requirements of high-resolution seismic exploration. In this study, a method of seismic data denoising is proposed based on the shearlet transform, a new multi-scale transform with multi-directions, multi-resolutions, and optimal sparse approximation properties as well as high computational efficiency. The shearlet transform can get rid of random noise while retaining effective signals to the maximum degree, thereby effectively improving the signal-to-noise ratio. It is applied to synthetic and field seismic data with different signal-to-noise ratios, and compared with conventional methods of seismic data denoising. Results show that the shearlet transform is competitive in denoising applications in terms of both performance and computational efficiency.