本文選題：南海神狐海域　切入點(diǎn)：砂巖型天然氣水合物　出處：《中國科學(xué)院研究生院(海洋研究所)》2015年碩士論文

【摘要】：本文對(duì)南海北部神狐海域天然氣水合物尤其是富砂儲(chǔ)層水合物的地球物理特征及成因機(jī)理進(jìn)行了研究。南海北部神狐海域GMGS-1鉆探資料顯示,SH4井在深度171-180m存在一個(gè)富砂儲(chǔ)層,測(cè)井結(jié)果表明在含水合物沉積層具有高P-波速度、高電阻率、低伽馬值、低密度的特征；而含游離氣沉積層具有低P-波速度、高電阻率、低伽馬值、低密度特征。伽馬測(cè)井值比已鉆獲水合物層(SH2,SH3,SH7井)的伽馬值明顯偏低。利用測(cè)井P-速度與伽馬測(cè)井值的交會(huì)分析區(qū)別出水合物層與游離氣層。通過對(duì)三維地震資料解釋,發(fā)現(xiàn)了SH4井位于峽谷底部一明顯NE-SW向沖蝕溝或侵蝕水道內(nèi),其下方存在明顯的滑塌作用。本文分析了該區(qū)砂巖儲(chǔ)層水合物的成因機(jī)理,認(rèn)為峽谷底部的濁流向下陸坡流動(dòng)過程中,在狹窄的水道負(fù)地形中發(fā)生匯聚作用,速度增加,濁流厚度增加,攜帶沉積物的能力增強(qiáng),會(huì)沉積較粗粒沉積物。同時(shí),由于峽谷西側(cè)壁沉積速率大,古水道被迅速充填掩埋在現(xiàn)今峽谷脊部之下,粗粒沉積得以保存,而且上部的細(xì)粒沉積形成良好的蓋層,可以有效阻礙下部天然氣的溢出,有利于砂巖型水合物形成。針對(duì)神狐海域含水合物層物性參數(shù)特征進(jìn)行了正演模擬及AVO特征分析,研究了水合物儲(chǔ)層頂?shù)捉缑娴姆瓷涮匦裕徊⑨槍?duì)南海北部陸坡神狐海域的測(cè)線進(jìn)行了約束稀疏脈沖反演,結(jié)果表明波阻抗反演方法能夠作為探測(cè)天然氣水合物的一種技術(shù)手段,并分別基于速度和電阻率估算了水合物飽和度,估算的天然氣水合物飽和度高達(dá)28%。
[Abstract]:In this paper, the geophysical characteristics and genetic mechanism of natural gas hydrates, especially sand rich reservoirs, in the Shenhu sea area of the northern South China Sea are studied. The GMGS-1 drilling data of Shenhu sea area in the northern South China Sea indicate that there is a sand rich reservoir in the depth of 171-180m. The logging results show that there are high P-wave velocity, high resistivity, low gamma value and low density in hydrate deposits, while those in free gas deposits have low P-wave velocity, high resistivity, low gamma value, low P wave velocity, high resistivity, low gamma value, low P wave velocity, high resistivity, low gamma value, low P wave velocity, high resistivity and low gamma value. The gamma-ray logging value is obviously lower than that of the well SH2H3H3H7, which has been drilled for hydrate formation. The hydrate layer and free gas reservoir are distinguished by the intersection analysis of logging P- velocity and gamma logging value, and the three dimensional seismic data are interpreted. It is found that the SH4 well is located in an obvious NE-SW trench or erosion channel at the bottom of the gorge, and there is obvious collapse under it. The genetic mechanism of hydrate in the sandstone reservoir in this area is analyzed in this paper. It is considered that in the process of the turbidity flow down the slope at the bottom of the canyon, convergence occurs in the negative topography of the narrow watercourse, the velocity increases, the thickness of the turbidity current increases, the ability of carrying sediment increases, and the coarse sediment is deposited. Because of the large deposition rate of the west side of the canyon, the ancient waterway was quickly filled and buried under the current valley ridge, and the coarse grain deposits were preserved, and the upper fine grain deposits formed a good caprock, which could effectively hinder the gas spillage in the lower part. In this paper, the forward modeling and AVO characteristic analysis of the physical parameters of hydrate layer in Shenhu sea area are carried out, and the reflection characteristics of the top and bottom interface of hydrate reservoir are studied. The constrained sparse pulse inversion is carried out in the Shenhu sea area on the northern slope of the South China Sea. The results show that the wave impedance inversion method can be used as a technical means to detect natural gas hydrate. The hydrate saturation is estimated based on velocity and resistivity, and the estimated gas hydrate saturation is as high as 28%.
【學(xué)位授予單位】：中國科學(xué)院研究生院(海洋研究所)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：P618.13

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

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本文編號(hào)：1690314