基于高分辨率地震技术的致密薄互储层预测
发布时间：2018-12-05 22:31
【摘要】：随着油气勘探技术的不断进展，勘探重点逐渐由常规的储层油气藏转向了具有复杂结构的储层，如致密薄互层，孔隙缝洞储层等等。这其中致密砂岩薄互层储层的主要特点是致密且渗透率低，，这类储层主要分布在鄂尔多斯盆地和松辽盆地。鄂尔多斯盆地北部的致密砂岩区的勘探关键是储层预测，针对此类地区，常规的储层预测工作的开展往往存在一定的困难，所得出结论的精确度通常存在进一步提高的空间。因此，为了满足此类复杂储层高分辨率储层预测的要求，可以结合叠前属性以及与频率相关的一些性质进行储层预测。本文以鄂尔多斯北部的典型致密砂岩薄互层区块为研究对象，进行高分辨率储层预测技术的研究。 本文首先对靶区进行叠前地震响应特征的分析，研究的目的区块是具有致密薄互结构的复杂储层，在调谐效应的影响下，顶底面的各种反射P波、S波，以及两反射面间的多次反射波、复合反射波等都会对研究结果产生影响,所以不能仅仅依靠常规的“亮点”来识别油气。于是，本文根据靶区已探明储油量井位的测井曲线以及反演结果获得正演模拟所需各项参数，建立不同储集条件下的薄层以及薄互层的正演模型，对其做叠前地震响应特征的研究分析。分析结果显示：在致密砂岩薄层，尤其是薄互层的储集条件下，由于受到调谐效应的影响，地震响应特征是十分复杂的，不同于常规储层的AVO变化规律，含气与非含气层的地震响应特征存在很大差异，但仍存在一定的规律可循，有助于进一步对储集类型进行识别。 此外，频谱分析技术在一定程度上可以在致密砂岩薄互层的碳氢检测中发挥作用,当储层为薄层或薄互层时，储层下方能够出现低频阴影，并且当频率逐渐升高时，低频阴影会逐渐消失。利用这一特性对靶区叠后数据进行频谱分析，得到不同频率下的分频剖面，观察不同频率下地震剖面的特征，与已探明井位的结果作对比，证实了利用频谱分析方法，依赖于含气层下方“低频阴影，高频消失”这一现象可以提高油气探测的精度。 本文还讨论了频散属性在致密砂岩薄互层的储层预测工作中的作用，地震波在传播过程中遇到含油气层时会发生能量衰减，同时伴随着速度以及频率的变化。因此，当地震波速度随频率规律性变化时，会成为有效的探测烃类的参数。为验证其有效性，首先结合了靶区数据建立了正演模型进行了频散属性的分析，从理论上证明相对于不含油气位置，含油气位置会出现频散属性的高值异常。又对靶区做了频散属性的分析，对比油气预测结果与实际测井结果，验证了频散属性可以应用于致密砂岩薄互层的储层预测工作中。 所以针对致密薄互层的特点，加强对叠前属性以及频率相关的属性的研究可以提高储层预测的效率及准确性。
[Abstract]:With the development of oil and gas exploration technology, the exploration emphasis has gradually shifted from conventional reservoirs to those with complex structures, such as tight thin interbeds, porous and fractured reservoirs, and so on. The main characteristics of tight sandstone thin interbedded reservoirs are compact and low permeability. These reservoirs are mainly distributed in Ordos Basin and Songliao Basin. Reservoir prediction is the key to the exploration of tight sandstone area in the north of Ordos Basin. In such areas, the conventional reservoir prediction work often has some difficulties, and the accuracy of the conclusions usually has room for further improvement. Therefore, in order to meet the requirement of high resolution reservoir prediction in this kind of complex reservoir, the prestack attributes and some properties related to frequency can be combined to predict the reservoir. In this paper, the typical tight sandstone thin interbed blocks in the north of Ordos are taken as the research object, and the high resolution reservoir prediction technology is studied. In this paper, the characteristics of prestack seismic response of target area are analyzed. The target block is a complex reservoir with compact and thin interstructure. Under the influence of tuning effect, all kinds of P wave and S wave are reflected from the top and bottom surface. As well as the multiple reflection between the two reflectors and the composite reflection will have an impact on the results of the study, so we can not only rely on the conventional "bright spot" to identify oil and gas. Therefore, according to the log curves and inversion results of the proven reservoir location in the target area, the parameters required for forward modeling are obtained, and the forward modeling of thin layers and thin interbeds under different reservoir conditions is established. The characteristics of prestack seismic response are studied and analyzed. The results show that under the condition of tight sandstone thin layer, especially thin interbed reservoir, the seismic response characteristics are very complicated due to the influence of tuning effect, which is different from the AVO variation law of conventional reservoir. The seismic response characteristics of gas-bearing and non-gas-bearing reservoirs are very different, but there are still some rules to be followed, which is helpful for further identification of reservoir types. In addition, spectrum analysis can play a role in hydrocarbon detection of thin interbedded tight sandstone to some extent. When the reservoir is thin or thin interbedded, the low frequency shadow can appear under the reservoir, and when the frequency increases gradually, The low-frequency shadows will fade away. By using this characteristic, the spectrum analysis of post-stack data of target area is carried out, and the frequency division profiles are obtained at different frequencies. The characteristics of seismic profiles at different frequencies are observed and compared with the results of proven well locations. The method of spectrum analysis is confirmed. Depending on the phenomenon of "low frequency shadow and high frequency vanishing" under the gas bearing formation, the accuracy of oil and gas detection can be improved. This paper also discusses the role of dispersion attributes in the prediction of tight sandstone thin interbedded reservoirs. The energy decay occurs when seismic waves encounter oil-bearing gas reservoirs in the process of seismic wave propagation, which is accompanied by changes in velocity and frequency. Therefore, when the velocity of seismic wave changes regularly with frequency, it becomes an effective parameter for hydrocarbon detection. In order to verify its validity, a forward model is established to analyze the dispersion attributes. It is theoretically proved that the high value anomalies of the dispersion properties occur in the locations containing oil and gas compared with the locations without oil and gas. The dispersion attributes of the target area are analyzed and compared with the actual well logging results. The results show that the dispersion attribute can be applied to the prediction of tight sandstone thin interbed reservoirs. Therefore, according to the characteristics of dense and thin interbeds, the study of prestack attributes and frequency-related attributes can improve the efficiency and accuracy of reservoir prediction.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P631.4;P618.13
[Abstract]:With the development of oil and gas exploration technology, the exploration emphasis has gradually shifted from conventional reservoirs to those with complex structures, such as tight thin interbeds, porous and fractured reservoirs, and so on. The main characteristics of tight sandstone thin interbedded reservoirs are compact and low permeability. These reservoirs are mainly distributed in Ordos Basin and Songliao Basin. Reservoir prediction is the key to the exploration of tight sandstone area in the north of Ordos Basin. In such areas, the conventional reservoir prediction work often has some difficulties, and the accuracy of the conclusions usually has room for further improvement. Therefore, in order to meet the requirement of high resolution reservoir prediction in this kind of complex reservoir, the prestack attributes and some properties related to frequency can be combined to predict the reservoir. In this paper, the typical tight sandstone thin interbed blocks in the north of Ordos are taken as the research object, and the high resolution reservoir prediction technology is studied. In this paper, the characteristics of prestack seismic response of target area are analyzed. The target block is a complex reservoir with compact and thin interstructure. Under the influence of tuning effect, all kinds of P wave and S wave are reflected from the top and bottom surface. As well as the multiple reflection between the two reflectors and the composite reflection will have an impact on the results of the study, so we can not only rely on the conventional "bright spot" to identify oil and gas. Therefore, according to the log curves and inversion results of the proven reservoir location in the target area, the parameters required for forward modeling are obtained, and the forward modeling of thin layers and thin interbeds under different reservoir conditions is established. The characteristics of prestack seismic response are studied and analyzed. The results show that under the condition of tight sandstone thin layer, especially thin interbed reservoir, the seismic response characteristics are very complicated due to the influence of tuning effect, which is different from the AVO variation law of conventional reservoir. The seismic response characteristics of gas-bearing and non-gas-bearing reservoirs are very different, but there are still some rules to be followed, which is helpful for further identification of reservoir types. In addition, spectrum analysis can play a role in hydrocarbon detection of thin interbedded tight sandstone to some extent. When the reservoir is thin or thin interbedded, the low frequency shadow can appear under the reservoir, and when the frequency increases gradually, The low-frequency shadows will fade away. By using this characteristic, the spectrum analysis of post-stack data of target area is carried out, and the frequency division profiles are obtained at different frequencies. The characteristics of seismic profiles at different frequencies are observed and compared with the results of proven well locations. The method of spectrum analysis is confirmed. Depending on the phenomenon of "low frequency shadow and high frequency vanishing" under the gas bearing formation, the accuracy of oil and gas detection can be improved. This paper also discusses the role of dispersion attributes in the prediction of tight sandstone thin interbedded reservoirs. The energy decay occurs when seismic waves encounter oil-bearing gas reservoirs in the process of seismic wave propagation, which is accompanied by changes in velocity and frequency. Therefore, when the velocity of seismic wave changes regularly with frequency, it becomes an effective parameter for hydrocarbon detection. In order to verify its validity, a forward model is established to analyze the dispersion attributes. It is theoretically proved that the high value anomalies of the dispersion properties occur in the locations containing oil and gas compared with the locations without oil and gas. The dispersion attributes of the target area are analyzed and compared with the actual well logging results. The results show that the dispersion attribute can be applied to the prediction of tight sandstone thin interbed reservoirs. Therefore, according to the characteristics of dense and thin interbeds, the study of prestack attributes and frequency-related attributes can improve the efficiency and accuracy of reservoir prediction.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P631.4;P618.13
【参考文献】
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1 邓继新,史
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