發(fā)布時間：2018-12-05 22:31

【摘要】：隨著油氣勘探技術的不斷進展，勘探重點逐漸由常規(guī)的儲層油氣藏轉向了具有復雜結構的儲層，如致密薄互層，孔隙縫洞儲層等等。這其中致密砂巖薄互層儲層的主要特點是致密且滲透率低，，這類儲層主要分布在鄂爾多斯盆地和松遼盆地。鄂爾多斯盆地北部的致密砂巖區(qū)的勘探關鍵是儲層預測，針對此類地區(qū)，常規(guī)的儲層預測工作的開展往往存在一定的困難，所得出結論的精確度通常存在進一步提高的空間。因此，為了滿足此類復雜儲層高分辨率儲層預測的要求，可以結合疊前屬性以及與頻率相關的一些性質進行儲層預測。本文以鄂爾多斯北部的典型致密砂巖薄互層區(qū)塊為研究對象，進行高分辨率儲層預測技術的研究。 本文首先對靶區(qū)進行疊前地震響應特征的分析，研究的目的區(qū)塊是具有致密薄互結構的復雜儲層，在調諧效應的影響下，頂底面的各種反射P波、S波，以及兩反射面間的多次反射波、復合反射波等都會對研究結果產生影響,所以不能僅僅依靠常規(guī)的“亮點”來識別油氣。于是，本文根據靶區(qū)已探明儲油量井位的測井曲線以及反演結果獲得正演模擬所需各項參數，建立不同儲集條件下的薄層以及薄互層的正演模型，對其做疊前地震響應特征的研究分析。分析結果顯示：在致密砂巖薄層，尤其是薄互層的儲集條件下，由于受到調諧效應的影響，地震響應特征是十分復雜的，不同于常規(guī)儲層的AVO變化規(guī)律，含氣與非含氣層的地震響應特征存在很大差異，但仍存在一定的規(guī)律可循，有助于進一步對儲集類型進行識別。 此外，頻譜分析技術在一定程度上可以在致密砂巖薄互層的碳氫檢測中發(fā)揮作用,當儲層為薄層或薄互層時，儲層下方能夠出現低頻陰影，并且當頻率逐漸升高時，低頻陰影會逐漸消失。利用這一特性對靶區(qū)疊后數據進行頻譜分析，得到不同頻率下的分頻剖面，觀察不同頻率下地震剖面的特征，與已探明井位的結果作對比，證實了利用頻譜分析方法，依賴于含氣層下方“低頻陰影，高頻消失”這一現象可以提高油氣探測的精度。 本文還討論了頻散屬性在致密砂巖薄互層的儲層預測工作中的作用，地震波在傳播過程中遇到含油氣層時會發(fā)生能量衰減，同時伴隨著速度以及頻率的變化。因此，當地震波速度隨頻率規(guī)律性變化時，會成為有效的探測烴類的參數。為驗證其有效性，首先結合了靶區(qū)數據建立了正演模型進行了頻散屬性的分析，從理論上證明相對于不含油氣位置，含油氣位置會出現頻散屬性的高值異常。又對靶區(qū)做了頻散屬性的分析，對比油氣預測結果與實際測井結果，驗證了頻散屬性可以應用于致密砂巖薄互層的儲層預測工作中。 所以針對致密薄互層的特點，加強對疊前屬性以及頻率相關的屬性的研究可以提高儲層預測的效率及準確性。
[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.
【學位授予單位】：吉林大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：P631.4;P618.13

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1 鄧繼新,史

本文編號：2365550