本文選題：黔中隆起　切入點(diǎn)：奧陶系　出處：《海相油氣地質(zhì)》2017年02期 　論文類型：期刊論文

【摘要】：以黔中地區(qū)下奧陶統(tǒng)為例,通過野外剖面觀測、實(shí)驗(yàn)分析等工作,揭示了白云巖的熱液-巖溶改造特征,并探討了其發(fā)育機(jī)理。研究區(qū)下奧陶統(tǒng)紅花園組和桐梓組以白云巖為主,在白云巖構(gòu)造裂縫和溶蝕孔洞中見白云石、方解石、瀝青的充填,具有典型的斑馬紋狀構(gòu)造。充填白云石為粗晶粒狀的鞍形白云石,具有彎曲晶面和波狀消光的特征,陰極發(fā)光呈現(xiàn)較強(qiáng)的紅色。充填白云石的碳同位素δ~(13)C在-2.2‰~-0.8‰之間,平均值為-1.47‰,氧同位素δ~(18)O在-12.2‰~-7.6‰之間,平均值為-9.4‰,與圍巖白云石相比明顯偏輕。充填白云石的稀土元素具有典型的Eu正異常特征,δEu最高達(dá)91.9。根據(jù)地質(zhì)演化背景和流體作用類型,奧陶系白云巖儲層發(fā)育過程為:早奧陶世沉積過程中發(fā)生同生/準(zhǔn)同生白云石化作用;中晚奧陶世至早志留世,受都勻運(yùn)動影響,白云巖暴露至地表遭受巖溶作用,形成巖溶孔洞型白云巖儲層;中泥盆世遭受構(gòu)造熱液進(jìn)一步對白云巖進(jìn)行的溶蝕改造,所形成的溶蝕孔洞為天然氣的主要儲集空間。
[Abstract]:Taking the Lower Ordovician in central Guizhou as an example, the characteristics of hydrothermal karst reconstruction of dolomite are revealed through field profile observation and experimental analysis. The development mechanism of dolomite, calcite and bitumen is mainly found in dolomite structural fractures and dissolution voids in the Lower Ordovician Red Garden formation and Tongzi formation, and the filling of dolomite, calcite and bitumen is found in the dolomite structural fractures and dissolution voids. It has a typical zebra grain structure. The dolomite filled with dolomite is a saddle-shaped dolomite with coarse grain shape, with the characteristics of curved crystal plane and wave-shaped extinction, and the cathodoluminescence is strong red. The carbon isotope 未 ~ (13) C of dolomite filled with dolomite is between -2.2 鈥，

本文編號：1559563