【作者】 李勇根；

【导师】 刘学伟；

【作者基本信息】 中国地质大学（北京） ， 地球探测与信息， 2009， 博士

【摘要】 我国探明原油及天然气地质储量中,致密砂岩气藏储量所占的比例逐年明显增大,占新增探明储量60%以上,各大油气区块均有低孔低渗透的致密砂岩气藏储层分布。因此,致密砂岩储层是21世纪最有希望的重要天然气勘探领域之一。致密砂岩储层因低孔隙性和含油气饱和度变化所产生的地球物理特征相对变化微弱,有利储层和气层预测一直是地震预测中的难点。本文以川中须家河组致密砂岩为代表,在归纳和总结前人工作的基础上,根据实际工区内储层特点,首先开展了针对目的层地震资料保幅处理,为叠前地震预测奠定基础;然后开展须家河组致密砂岩地震岩石物理基础分析,针对储气层地球物理响应特点,优选了有效的识别储层和气层敏感弹性参数;最后通过现有的和自主改进反演方法进行了叠前地震反演。通过钻井证实,本次研究在致密砂岩储层预测和油气检测中取得了良好效果,取得的主要研究成果如下:1、川中须家河组储层物性差、有效储层单层比较薄、储集空间以次生溶孔为主。提出了技术上追求须家河组整体描述,不再拘泥于单层薄层识别精度观点。2、结合实际地震资料,详细分析了影响保幅处理的主要因素,提出了基于AVO属性保护的去噪方法,针对保幅处理过程中的难点提出了关键和主要技术,并形成了一套有效的地震资料保幅处理流程。3、在深入分析致密砂岩储气层的地球物理响应特征的基础上,利用研究区实际测井数据开展了致密砂岩地震正演模拟研究,揭示了地层厚度、孔隙度、流体饱和度变化引起地震响应变化的一般规律。从理论上探索了利用地震资料预测有利储层和气层的可行性。4、针对川中须家河组地区,建立了一套系统的致密砂岩储层和气层地震岩石物理敏感参数分析技术,为海量的叠前地震数据反演快速地提供了技术依据。5、通过本次研究,筛选出川中须家河组地区致密砂岩有效储层预测技术:岩性阻抗-横波阻抗预测技术、弹性阻抗预测技术。筛选出致密砂岩气层检测技术:弹性阻抗系数技术、λρ弹性参数反演技术。6、首次建立弹性阻抗系数、孔隙度和含气饱和度岩石物理图板,开展了预测含气饱和度研究,预测果与实际研究工区整体构造—岩性气藏特点较吻合。更多还原

【Abstract】 Tight hydrocarbon-bearing sandstone reservoir accounts of more and more proportion in China’s proved reserves of crude oil and natural gas year by year. Tight sandstone reservoir with low porosity and low permeability also distributes in the major oil and gas blocks in China. Therefore, it is one of the most promising and important fields for exploration in the 21st century.For the weak relative changes in geophysical characteristics to different porosity and hydrocarbon saturation, effective prediction and hydrocarbon detection are very difficult for tight sandstone reservoirs. This paper bases on predecessors’ work and the objective reservoir characteristics of Xujiahe group formation, carries out the processing system to maintain seismic data amplitude and seismic rock physics analysis, analyses hydrocarbon-bearing reservoir ’s geophysical response characteristics, optimizes the effective elastic sensitive parameters, and then researches pre-stack inversion method by improved inversion algorithm and their application on tight sandstone reservoir prediction and hydrocarbon detection. Thesis main includes the following contents:1) The formation of Xujiahe group has the characteristics of thin layer and poor reservoir properties with secondary dissolution porosity. Effective prediction and hydrocarbon detection are very difficult for tight sandstone reservoirs. So, the paper pursuits the overall description and no longer rigidly adheres to the views of single thin layer identification accuracy.2) Based on the actual seismic data processing, this thesis detailed analyses the main factors which impact the seismic data fidelity, and put the new de-noising method according to the AVO attribution. The paper also forms a set of seismic data fidelity treatment system and key technology for maintaining amplitude accuracy.3) Thesis first time analyses hydrocarbon-bearing reservoir’s geophysical response characteristics of tight sandstone reservoir, and launches forward modeling studies of tight sandstone reservoir based on logging data in site to explore the general laws of seismic response in different frequency bands. These laws are affected by different layer thickness, porosity and fluid saturation. That is to say, the paper researches the feasibility to predict effective reservoir and detect hydrocarbon in theoretical by using seismic data.4) Thesis first time establishes a set of seismic rock physics sensitivity parameters analysis system for tight hydrocarbon-bearing sandstone reservoir of the formation of Xujiahe group. It provides a technical basis for the rapid inversion of massive pre-stack seismic data.5) Thesis picks out the effective reservoir prediction technology of tight sandstone, such as lithology impedance-Vs impedance prediction technique, elastic impedance prediction technique. Thesis also picks out the effective hydrocarbon detection technology, such as elastic impedance prediction technique,λρinversion technique.6) Thesis first time creates a seismic rock physics board using the in suit logging data, and carries out the hydrocarbon saturation prediction. It should to be noted that the forecast result matches the characteristics of structure-lithology gas reservoir in whole.更多还原