本文關(guān)鍵詞： 熱液白云巖 晶間孔 碳氧同位素 英西地區(qū) 柴達(dá)木盆地　出處：《地質(zhì)科技情報(bào)》2017年01期 　論文類型：期刊論文

【摘要】：通過(guò)巖心及微觀巖石學(xué)特征、結(jié)構(gòu)特征、微量元素和碳氧同位素地球化學(xué)特征的綜合研究,首次在柴達(dá)木盆地英西地區(qū)發(fā)現(xiàn)了一種罕見(jiàn)的熱液改造型白云巖儲(chǔ)集層,但熱液改造程度不強(qiáng),主要包括以下幾個(gè)方面:1主要儲(chǔ)集層較為致密,主要發(fā)育泥晶結(jié)構(gòu)的鐵白云石和方解石,偶見(jiàn)鈉長(zhǎng)石、黃鐵礦、重晶石和天青石等熱液礦物;2碳酸鹽礦物中富含F(xiàn)eO、MnO等,其平均質(zhì)量分?jǐn)?shù)分別為4.112%和0.186%,顯著高于本區(qū)準(zhǔn)同生交代成因白云石中鐵錳含量,且鈣、鎂含量也有所升高,反映了熱液流體為富含Ca~(2+),Fe~(2+),Sr~(2+),Mn~(2+)和少量Mg~(2+)等多種離子的堿性熱鹵水;3ΣREE具有較大的變化范圍且總量較高,稀土元素配分模式具有明顯的Eu負(fù)異常,代表了湖泊環(huán)境特有的熱流體稀土元素組成特征,形成于偏堿性的深湖熱鹵水還原環(huán)境;4δ18OPDB變化范圍為-6.8‰~-3.6‰,平均值為-5.2‰,介于熱液白云巖和準(zhǔn)同生交代成因白云巖之間,顯示了英西地區(qū)漸新統(tǒng)白云巖在準(zhǔn)同生交代成因基礎(chǔ)上受到了一定程度的熱液改造。裂縫的發(fā)育程度和與熱液通道的距離遠(yuǎn)近不同而使得樣品的改造程度存在一定的差異性。綜上所述,熱液改造型白云巖儲(chǔ)集層的首次發(fā)現(xiàn)開(kāi)拓了柴達(dá)木盆地英西地區(qū)深層致密油氣勘探的新視野,這一研究成果對(duì)英西深層尋找優(yōu)質(zhì)"甜點(diǎn)"儲(chǔ)層具有重要指導(dǎo)意義。
[Abstract]:A rare hydrothermal reformed dolomite reservoir was first discovered in Yingxi area of Qaidam Basin through a comprehensive study of core and microscopic petrological characteristics, structural characteristics, trace elements and carbon and oxygen isotopic geochemistry. However, the degree of hydrothermal transformation is not strong, mainly including the following aspects: the main reservoir of 1: 1 is relatively compact, the main mud-crystal structure of iron dolomite and calcite, occasionally albite, pyrite, The carbonate minerals such as barite and celadite are rich in Feo _ (2) mn _ O, the average mass fraction of which is 4.112% and 0.186, respectively, which is significantly higher than the iron and manganese content in the pseudo-synmetasomatic dolomite, and the contents of calcium and magnesium are also increased. The results show that the alkaline hot brine 3 危 REE, which is rich in Ca~(2 and Mg~(2, has a larger range of variation and higher total amount, and the REE partition model has obvious negative EU anomaly. It represents the characteristic of REE composition in the lake environment and is formed in the alkaline deep lake hot brine reduction environment with a range of -6.8 鈥，

本文編號(hào)：1505071