页岩气高精度三维地震勘探技术的应用与探讨——以四川盆地焦石坝大型页岩气田勘探实践为例  

Application of 3D high-precision seismic technology to shale gas exploration:A case study of the large Jiaoshiba shale gas field in the Sichuan Basin

作　　者：陈祖庆[1] 杨鸿飞[1] 王静波[1] 郑天发[1] 敬朋贵[1] 李苏光[1] 陈超[1] 

机构地区：[1]中国石化勘探分公司

出　　处：《天然气工业》2016年第2期9-20,共12页Natural Gas Industry

基　　金：中国石油化工股份有限公司科技部项目"四川盆地及周缘区块下组合页岩气形成条件与有利区带评价研究"(编号:P13129)

摘　　要：中国南方海相页岩气成藏模式与北美地区存在着明显的差异,前者储层厚度普遍较薄且保存条件复杂,常规的二维、三维地震勘探技术难以精细刻画泥页岩层的构造特征并准确反映优质泥页岩的分布规律,因而影响了页岩气水平井井位部署的成功率。要想在中国南方海相沉积区获得页岩气商业产能,就必须实施面向岩性勘探的三维高精度地震勘探,准确描述页岩气"甜点"的分布情况。因此,针对四川盆地东南部涪陵焦石坝地区复杂的地震、地质条件,三维高精度地震采集观测系统的设计应该具备宽方位、小道距、高覆盖、纵横向覆盖均匀、适中排列的特点,以满足页岩气勘探对构造解释、岩性解释以及裂缝预测的需要。基于该思路,2013年在该区实施的首个高精度三维地震勘探项目对焦石坝大型页岩气田的发现起到了重要的促进作用。基于四川盆地海相优质泥页岩从志留系到寒武系呈多层系发育的特点,可以实施页岩气立体勘探的策略,充分挖掘高精度三维地震资料中所包含的浅、中、深地层的油气信息,全面扩大勘探成果,以平衡页岩气勘探开发高昂的上游成本,持续推动该区页岩气高效勘探开发进程。The accumulation pattern of the marine shale gas in South China is different from that in North America. The former has gen- erally thin reservoirs and complex preservation conditions, so it is difficult to make a fine description of the structural features of shale formation and to reflect accurately the distribution pattern of high-quality shale by using the conventional 2D and 3D seismic exploration technology, which has an adverse effect on the successful deployment of horizontal wells. In view of this, 3D high-precision seismic ex- ploration focusing on lithological survey was implemented to make an accurate description of the distribution of shale gas sweet spots so that commercial shale gas production can be obtained. Therefore, due to the complex seismic geological condition of the Jiaoshiba area in Fuling, SE Sichuan Basin, the observation system of 3D high-precision seismic acquisition should have such features as wide-azimuth angles, small trace intervals, high folds, uniform vertical and horizontal coverage and long spread to meet the needs of the shale gas ex- ploration in terms of tectonic interpretation, lithological interpretation and fracture prediction. Based on this idea, the first implemented 3D high-precision seismic exploration project in the Jiaoshiba area played an important role in the discovery of the large Jiaoshiba shale gas field. Considering that the high-quality marine shale in the Sichuan Basin shows the characteristic of multi-layer development from the Silurian system to the Cambrian system, the strategy of shale gas stereoscopic exploration should be implemented to fully obtain the oil and gas information of the shallow, medium and deep strata from the 3D high-precision seismic data, and ultimately to expand the prospecting achievements in an all-round way to balance the high upstream exploration cost, and to continue to push the efficient shale gas exploration and development process in China.

关 键 词：四川盆地 东南部 海相 焦石坝大型页岩气田 高精度三维地震勘探 立体勘探 “甜点”预测 油气信息 

分 类 号：P618.13[天文地球—矿床学] P631.4[天文地球—地质学]