【作者】 唐湘蓉；

【导师】 贺振华； 黄德济；

【作者基本信息】 成都理工大学 ， 地球探测与信息技术， 2005， 硕士

【副题名】以塔河4号油区带为例

【摘要】 对于精细油气勘探来说,地震反演成果在油藏描述及油气横向预测等研究工作中所起的作用也越来越重要,它能较真实地反映出地下的地质构造和储层的岩性特征,能够大大提高钻井的成功率。塔河油田奥陶系碳酸盐岩储层以岩溶、构造运动形成的岩溶缝洞和构造裂缝为主,具有埋藏深,非均质性强的特点。加之奥陶系顶部地层遭受过强烈风化剥蚀,其地震反射信号能量弱且杂乱、地震分辨率不高,加大了碳酸盐岩缝洞型储集层精确预测的难度。针对塔河油田碳酸盐岩储层的特点和预测难点,本文在充分吸收前人关于碳酸盐岩缝洞型储层的研究成果的基础上,应用目前油气勘探领域中用于储层预测的多种地震测井联合反演方法(约束稀疏脉冲反演、地震特征参数反演、随机模拟及随机反演等)对该区储层进行预测。在研究过程中,采用“五点钟型”滤波方法、线性校正关系,对测井曲线进行预处理和标准化处理,以保证储层反演工作的合理性;对每种方法的原理、关键技术、适用条件进行了详细研究,分析了每种方法的优缺点;并对每种反演方法的实际应用效果进行了分析比较,优选出适合本区碳酸盐岩储层预测反演方法和处理流程。取得了以下成果和认识: 1) 递推反演方法,以地震资料为主,测井资料不参与反演约束,其分辨率、信噪比及可靠程度完全依赖于地震资料本身的品质,地震噪音对反演结果敏感、影响较大,地震带宽窄导致分辨率相对较低,难以满足薄储层描述的要求。 2) 约束稀疏脉冲反演方法,假设地层的反射系数是稀疏的,利用地震解释层位和井约束控制波阻抗的趋势和范围,采用一个快速的、趋势约束的脉冲算法产生宽带结果。反演结果既较忠实于地震资料,能反映储层的横向变化,又补充了部分低频和高频成分,纵向分辨率较常规地震资料有所提高。但该方法只对大的事件进行迭代反演,不能反映储层纵向细微变化,且受约束条件和子波的影响较大。 3) 地震特征参数反演方法,实质上是地震控制下的测井属性反演。它充分利用地震、测井、地质等信息,采用地震特征、地质模型和测井等约束条件,通过主组分分析、奇异值分解技术,根据地震资料可反演出电阻率、自然伽玛、孔隙度等多种属性剖面,能够解决波阻抗反演不能解决的问题,更加有效地进行储层的预测和描述,分辨率较常规地震资料成倍提高,反演结果也较好地反映了井间储层岩性、物性。但该方法受初始模型影响较大,反演结果过于层状化,对碳酸盐岩缝洞储层的预测不是更多还原

【Abstract】 With regard to delicate oil-gas exploration, the results of seismic inversion play a more and more important role in the oil pool description and lateral in oil-gas prediction. The technology can actually reflect underground geological structured and reservoir rock character, and can greatly raise the percentage of drilling hits. The Ordovician carbonate reservoirs of Tahe oilfield are characterized mainly by karstic fissures and vugs, and structural fissures formed by karsticfication and geo-tectonics, and characterized by deep burying and strong heterogeneity. Additionally, because the top strata of Ordovician have been subjected to intensive weathering and denudation, the energy of seismic reflection signals is weak and random and the seismic resolution is low, which multiplies the degree of difficulty in accurately predicting carbonate reservoirs of fissure-vug type. In view of the characteristic of carbonate reservoirs of Tahe oilfield and their difficult point in predicting, on the basis of fully consulting the study result of carbonate reservoirs of fissure-vug type, the thesis uses multiple methods of seismic and logging joint inversion (including Recursive trace inversion, Constrained sparse spike inversion, Seismic characteristic inversion, Random simulation and stochastic inversion; reservoir prediction, etc) to predict reservoirs of this area. In the course of study, the author takes the five-clock-type filter method and the relation of linear calibration in the pretreatment and standard treatment of logging data for ensuring the rationality of reservoir inversion, and takes a detailed research on the principles, key technology and applied conditions of every methods, analyses strong and weak point of every kinds of inversion, and compares applied effectiveness of every inversion methods, so that the optimized inversion method, which is suited to the carbonate reservoirs prediction of the area, is selected. Several points of my understanding are follows:1. The method of Recursive trace inversion uses mainly seismic data, and logging data are not involved in the inversion constraint. The resolution, signal-to-noise and reliability are all dependent on the quality of seismic data themselves. Hence, the seismic noise is sensitive to inversion result and has considerable influence. The width and narrowness of seismic bands can result in the comparative lowering of resolution, which cannot meet the requests of thin reservoir description.2. The method of constrained sparse spike inversion supposes that the reflections coefficients of strata are sparse. A rapid trend-constrained pulse inversion calculation is adopted, using the seismic interpretation horizon and logging-constraint to control the trend and scope of wave impedance. The pulse calculation can obtain the wide-band result. The inversion result is faithful to seismic data and can reflect the lateral change of reservoirs. And the constraint of logging and geology can replenish the component of low and high frequencies. The vertical resolution is heightened comparatively to the conventional seismic data.更多还原