【摘要】：前寒武系是全球一個(gè)重要的含油氣層系。塔里木盆地該層系埋深大,一直未取得勘探突破,是否發(fā)育優(yōu)質(zhì)烴源巖也不確定。塔里木盆地西南部及昆侖山前十余萬平方公里范圍內(nèi),已鉆探30多口探井,雖然發(fā)現(xiàn)了和田河、巴什托普、玉北、羅斯2等海相油氣田,但始終未鉆遇寒武系或奧陶系烴源巖,其油氣來源也存在爭(zhēng)議。近期筆者在盆地西南部踏勘中,發(fā)現(xiàn)一套巨厚的黑色頁巖和泥巖,出露較好。實(shí)測(cè)泥頁巖厚度大于140 m(未見頂,花崗巖體侵位),有機(jī)碳含量(TOC)主要分布在0.6%~1.9%,83塊樣品平均TOC為1.0%。最高熱解溫度Tmax主要分布在490~520℃,相當(dāng)于Ro在1.9%~2.9%。泥巖層中黃鐵礦十分富集。根據(jù)地層接觸關(guān)系及同位素定年,該地層年齡可能大于517 Ma,準(zhǔn)確定年目前正在進(jìn)行,因此暫且命名為"西昆侖黑色巖系"。通過板塊構(gòu)造分析,這套厚層泥巖可能在塔里木盆地西南部廣泛分布,其形成有可能受裂陷槽的控制。這套黑色泥巖很可能是塔西南地區(qū)重要的烴源巖,提出塔里木盆地前寒武系—寒武系具備油氣成藏的地質(zhì)條件,該發(fā)現(xiàn)必將推動(dòng)塔里木盆地向深層—超深層以及古老層系開展油氣勘探工作。
[Abstract]:Precambrian is an important hydrocarbon bearing system in the world. The depth of the strata in Tarim Basin is large and the exploration breakthrough has not been achieved. It is also uncertain whether high-quality source rocks will be developed or not. In the southwest Tarim Basin and over 100,000 square kilometers before Kunlun Mountain, more than 30 exploration wells have been drilled. Although marine oil and gas fields such as Hetian River, Bashtop, Yubei and Ross 2 have been discovered, the Cambrian or Ordovician source rocks have never been drilled. The source of oil and gas is also controversial. Recently, during the exploration of the southwest of the basin, the author found a set of thick black shale and mudstone, which are well exposed. The measured shale thickness is more than 140m (no crest, granite emplacement), the organic carbon content (TOC) is mainly distributed in 0.6% ~ 1.9%, and the average TOC of 83 samples is 1.0%. The highest pyrolysis temperature (Tmax) is mainly distributed at 490 鈩，

本文編號(hào)：2452010