頁籤選單縮合
| 題 名 | 澳洲Vulcan次盆地中岩心與岩屑的油岩對比及其主要生油岩之油氣生成潛能=Oils-source Correlation and Source-rocks Potential in the Vulcan Subbasin, Northwestern Australia |
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| 作 者 | 沈俊卿; | 書刊名 | 臺灣石油地質 |
| 卷 期 | 37 民94.12 |
| 頁 次 | 頁137-156 |
| 分類號 | 457.2 |
| 關鍵詞 | 生油岩潛能; 油岩對比; 成熟度; Source rock potential; Oil source correlation; Maturity; |
| 語 文 | 中文(Chinese) |
| 中文摘要 | 在缺乏油樣但卻有儲集層岩心以及在岩樣數量太少導致無法進行正常的萃取分析之情況下,本報告嚐試以所獲得之少量樣品藉由熱裂解吸附氣相層析作油、油或油、岩對比。將井下儲集層岩心以熱裂解吸附分析結果顯示East Swan-2樣品之pristane/phytane、pristane/nC17及phytane/nC18值,與其他井下儲集層岩心(油樣)熱裂解吸附的值有極大的差異,所有儲集層岩心的這些值與Taltarni-1 3297公尺煤樣熱裂解吸附之結果不同。甲基菲(MP)及甲基菲的MPDF比值亦顯示BILYARA-1 2629.8m與MONTARA-1 2660m的油相似而卻與上述煤屑並不相同。將這些井下岩心進行一般的萃取分離後,所得飽和烃經氣相層析分析結果,pristane/nC172對phytane/nC18較儲集層鄰近深度之頁岩岩層以相同方法分析所得之值為低,顯示油樣有較高的成熟度值,而East Swan-2樣品的pristane/nC17對phytane/nC18值也與熱裂解吸附分析所獲得的結果相似,顯示與其他樣品有極大差異。另外萃取分離的芳香烃以MPI-1計算油樣之成熟度,計算方式以Radke (1988)的式子較為正確,油樣之成熟度值介於0.53-0.7% Rc,相較於Montara-1井下頁岩岩屑萃取分析所得之成熟度值(2952公尺之0.52% Rc及3402公尺之0.58% Rc),而由MPDF所換算的成熟度值則較MPI-1為高,有兩個油樣為生油高峰產物,不論依據何值以儲集層現有深度之生油岩均較油樣成熟度值為低,顯示油樣移棲自較深處,而大部份樣品的PI分佈趨勢值顯示在0.7% Ro時可達0.3。連續性的變化顯示其轉化率在0.7% Ro時僅30%。三個成熟度在油窗起始點的油樣,可能來自較高的轉化率樣品。盆地東南側油窗深度依岩屑所測得的鏡煤素反射率值顯示應介於3000-3500公尺左右。 此盆地中Lower Vulcan FM為主要生油岩,含陸源生油岩其有機富集度介於0.6~3.5% TOC,氫指數(HI)低於400 mg HC/g TOC,部份樣品可達500 mg HC/g TOC。因惰煤素含量與氫指數成反比,此一趨勢顯示,若去除惰煤素影響則Lower Vulcan FM生油岩之氫指數值介於300-400 mg HC/g TOC,實際油氣潛能則應如上述。由於大部份樣品的氧指數值(OI)偏高,故可確認第三類型有機物為其主要組成。惰煤素的存在雖會影響氫指數卻不影響生產指數(PI),以生產指數判斷油氣轉化率不致失誤。Lower Vulcan地層下覆的Plover地層為含煤地層,已公開的資料顯示生油潛能HI有一半大於400 mg HC/g TOC,是具產油潛能的煤層。經檢視此區域含有煤層的井共有八口井,多位於盆地東南。煤層主要出現在170~210Ma的地層,即早侏羅的Plover地層。 |
| 英文摘要 | As results of thermal extraction core sample from East Swan-2 well have obvious discrepancy of pristane/phytane、pristane/nC17 and phytane/nC18 values compared to others reservoir core samples. These values from whole cores have little similarity to that from coal cuttings at the Taltarni-1 well (3297 m). Compounds ratio like as methylphenanthrene isomer in thermal extration chromatogram have similar values for cores of Biyara-1 2629.8m and Montara-1 2660m, but are different from coal cuttings of Taltarni-1 3297 m. Reservoir cores and coal cuttings were analysed by using thermal extration to understand its relationships between each others for laking oil samples and enough quantity coal samples. Reservoir cores and shale cuttings were treated with general soxhlet extraction to check the result of the thermal extraction analyses. Few compounds acting as tools for maturity and environment, pristane/phytane、pristane/nC17、phytane/nC18 and methylphenanthrene isomer, were selected to compare the results from these two methods for recognizing easily compounds from thermal extraction chromatogram. The result of soxhlet extraction show that reservoir core have lower pristane/nC17、phytane/nC18 ratio compared to those from shale cuttings, and they are in the same trend except one core from East Swan-2 well. This means residual oils from reservoir core have higher maturity than those from underlying shale samples. A maturity tool of aromatics basing on methylphenanthrene isomer shows that calculated maturity using Radke's equation (1988) for shale cuttings are closer to the vitrinite reflectance measuring for nearby cutting coal. Based on this equation the maturity of residual oils in reservoir cores range from 0.53-0.7% Rc and higher than those from cutting shales in the Montara-1 well. The maturity calculated from MPDF is higher than that of MPI-1. Two residual oils are products of peak oil generation The interval entering oil window range from 3000-3500 meters based on the vitrinite reflectance measuring for coals and shale cuttings. This interval similar to those of Taiwan. This means oils migrate from deeper section, except immature one. The production index of most public data have an obvious trend increasing with maturity to 0.3 at maturity 0.7% Ro, which means the transformation of hydrocarbon is about 30% similar to those in Taiwan. The most important source rock, the lower Vulcan Fm, in the Vulcan sub-basin is well known. Its organic richness range from 0.6-3.5% TOC. Hydrogen index (HI) of most samples are lower than 400 mg HC/g TOC and part of samples reach 500 mg HC/g TOC. The HI value decrease with increasing inertinite content. The trend of this distribution show that the actual HI values should be range from 300-400 mg HC/g TOC exclude inertinite. This value are of the type III kerogen. Therefore, the result of HI value, lower than 250 mg HC/g TOC, in this study are underestimate. Most of analyzed samples of the Lower Vulcan Fm from public data are with higher oxygen index (OI) as to be classified as type III kerogen. The higher oil prone source rock is underlying formation, the Plover Fm. It is a coal-bearing formation. Half of analyzed samples from public data are higher than 400 HC/g TOC. Coal measure were found in eight wells in the southeastern part of this sub-basin. Most of coal measures accumulated during 170-210 Ma as the Plover Fm deposited. |
本系統中英文摘要資訊取自各篇刊載內容。