渝黔湘秀山区块页岩气二维地震勘探研究

2D seismic exploration of Xiushan block shale gas in Chongqing,Guizhou and Hunan

目前对南方海相地区页岩气的研究多集中在成藏模式、有利区评价等基础地质理论。在应用页岩气地球物理技术进行页岩气高产富集区识别预测和评价方面进行了一些探索,尚未形成一套完整且有别于常规油气勘探技术思路与方法。在野外地质调查和区域地质认识的基础上,渝黔湘秀山页岩气区块部署实施二维地震勘探剖面13条,523.5 km.区内地形复杂,障碍物较多,数据采集难度大;灰岩出露覆盖范围广,浅层地震地质条件较差,地震记录信噪比低,静校正问题、速度分析困难等问题突出。通过地震资料采集、处理、解释、储层与流体识别等技术一体化攻关,获得了高信噪比地震资料,结合勘查区页岩气地质条件,综合录井、测井等勘查手段,形成一套完整的、针对盆缘山区海相页岩气地球物理勘探技术流程。采集、处理、解释一体化结合:优选最佳基准面静校正方法,解决静校正;叠前去噪,提高信噪比;叠加及偏移成像,改善成像质量。探索应用地震储层反演与气层检测技术,预测页岩气"甜点"分布区,为部署井位提供基础。二维勘探精细标定出了2套目的层顶面构造形态和埋深,区内断层以北东向和近南北向为主;优选了2套目的层有利目标区,部署了2口参数井井位。

At present, most of the research on the marine shale gas in south of China is focus on the basic geological theory which have been centered on its accumulation mode, favorable area evaluation, etc. In the application of geophysical techniques to identify shale gas prediction and evaluation of shale gas yield rich region some explorations carried out, while the complete set of technology idea and method un-like conventional oil and gas exploration is still at the exploratory stage. On the basis of field geological survey and the regional geological understanding, thirteen 2D seismic profiles, totally 523.5 km have been carried out. Since the relief is complex, there are more obstacles, the seismic data acquisition is dif- ficult; wide limestone covering, poor shallow seismic geological conditions,low seismic record S/N ratio, thus caused conspicuous problems in statics correction and velocity analysis. Through integrate research of seismic data acquisition, processing, interpretation, reservoir fluid identification, the seismic data of high signal-to-noise ratio was obtained. And then the mountain marine shale gas geophysical exploration technology was developed with respect of the shale gas geological seismic conditions in the block. The optimal datum static correction method was used to solve static correction, pre-stack de-noising to im- prove the signal-to-noise ratio, overlay and migration to improve the image quality. On this basis, discover the seismic inversion of reservoir and gas detection technology, provides a solid foundation for Block opti- mization and well location selection. This prospecting depicted fine the top structural configurations and the buried depths of the Longmaxi groups and the Niutitang groups, East and north of the fault zone near the main north-south ; preferably two sets of target layer favorable target areas, the deployment of two pa- rameters wells bit.