波阻抗反演及在碳酸盐岩储层预测中的应用

发布时间：2018-03-18 01:12

本文选题：碳酸盐岩　切入点：约束稀疏脉冲反演　出处：《成都理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：碳酸盐岩储集层是全球极为重要的产油气层,其油气储量占已发现总资源量的50%以上,世界上大部分大中型油气田的主力产油气层均为碳酸盐岩地层。总体来说,碳酸盐岩储层类型较多,内部非均质性强,分布发育受沉积环境和成岩作用的控制,这些特征大大增加了储层预测的难度。波阻抗反演能够将测井资料和地震资料有效的结合起来,推算出目标地层的波阻抗,再利用储层和围岩在波阻抗上的差异,将储层识别出来,是一种为数不多的较为有效的碳酸盐岩储层预测手段。本文所研究的区域位于川西孝泉-新场构造带,该区域储层厚度薄、地震分辨率低,常规的波阻抗反演(如约束稀疏脉冲反演)受到地震分辨率限制无法精确展示储层与围岩的波阻抗差异。因此,本文引入了以地质统计学为基础的随机反演方法。随机反演方法以地质框架模型、测井和地震资料为依据,对储层油气藏的空间分布规律、相关性以及物性参数进行随机模拟,获得一组等概率的储层油气藏参数模型,利用已知资料分析确定储层油气藏参数的空间分布规律(直方图)和空间相关性(变差函数),生成即满足测井资料,又满足地震资料的储层油气藏参数模型,对不确定性进行定量分析,获得比常规地震反演分辨率更高且又与地质特征吻合的波阻抗和岩性信息。本文的主要是针对叠后递推反演方法中的约束稀疏脉冲反演和地质统计学反演中的随机反演来进行实际应用中的研究。首先介绍了地震波阻抗反演的现状和发展趋势;详细研究了波阻抗反演的基本理论、分类以及不同反演技术的局限性;然后针对川西地区碳酸盐岩储层的自身特点,选择了约束稀疏脉冲反演和基于地质统计学的随机地震反演,深入研究分析了两种方法的原理、各项关键技术(包括地震及井数据处理,子波提取与合成记录,初始模型建立,反演质量监控等;以及在地质统计学随机地震反演中用到的概率密度函数和变差函数)和各自的优势特点;最后用Jason反演软件的Inver Trace-plus模块进行了约束稀疏脉冲反演,而Stat Mod MC模块进行了随机地震模拟以及地质统计学随机反演,在反演过程中,各项反演参数占了重要地位,通过反演的结果,可以对储层大致范围进行描述和预测。在实际应用的基础上,分析各种反演方法的主要影响因素,分析对比进行波阻抗反演得到的结果的差异。对比约束稀疏脉冲反演的结果,可以看到随机地震反演结果的垂向分辨率有了非常明显的提高。
[Abstract]:Carbonate reservoir is one of the most important oil and gas producing zones in the world. Its oil and gas reserves account for more than 50% of the total discovered resources. The main oil-producing reservoirs in most large and medium-sized oil and gas fields in the world are carbonate strata. There are many types of carbonate reservoirs, the internal heterogeneity is strong, the distribution and development of carbonate reservoirs are controlled by sedimentary environment and diagenesis. These characteristics greatly increase the difficulty of reservoir prediction. Wave impedance inversion can effectively combine logging data with seismic data to calculate the wave impedance of target formation, and then make use of the difference between reservoir and surrounding rock in wave impedance. Identifying the reservoir is one of the few effective means of carbonate reservoir prediction. The area studied in this paper is located in the Xiaoquan-Xinchang structural belt of western Sichuan, where the reservoir thickness is thin and the seismic resolution is low. Conventional wave impedance inversion (such as constrained sparse pulse inversion) cannot accurately show the difference between reservoir and surrounding rock wave impedance due to seismic resolution limitation. In this paper, a stochastic inversion method based on geostatistics is introduced. Based on geological frame model, logging and seismic data, the spatial distribution, correlation and physical parameters of reservoir reservoir are simulated randomly. A set of equal probability reservoir parameter models are obtained, and the spatial distribution law (histogram) and spatial correlation (variation function) of reservoir parameters are determined by analyzing the known data. The parameter model of reservoir oil and gas reservoir is satisfied with seismic data, and the uncertainty is analyzed quantitatively. Wave impedance and lithology information with higher resolution than conventional seismic inversion and consistent with geological characteristics are obtained. This paper focuses on constrained sparse pulse inversion and geostatistical inversion in poststack recursive inversion. The present situation and development trend of seismic wave impedance inversion are introduced in this paper. The basic theory, classification and limitation of different inversion techniques of wave impedance inversion are studied in detail. The constrained sparse pulse inversion and stochastic seismic inversion based on geostatistics are selected. The principles of the two methods are deeply studied and analyzed. The key techniques are seismic and well data processing, wavelet extraction and synthesis, initial modeling. Inversion quality monitoring and so on; probability density function and variation function used in geostatistics random seismic inversion) and their advantages. Finally, the constrained sparse pulse inversion is carried out using Inver Trace-plus module of Jason inversion software. The Stat Mod MC module carries out random seismic simulation and geostatistical stochastic inversion. In the inversion process, the inversion parameters play an important role. On the basis of practical application, the main influencing factors of various inversion methods are analyzed, and the differences of the results obtained from wave impedance inversion are analyzed. It can be seen that the vertical resolution of random seismic inversion results has been greatly improved.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.13;P631.4

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