【摘要】：河套盆地臨河坳陷是油氣勘探的重要地區(qū),一直以來(lái)備受人們的關(guān)注。該區(qū)共鉆井11 口,有6 口井見(jiàn)油顯示,但未獲得工業(yè)油流。由于前期鉆井主要集中在臨河坳陷的東南部,對(duì)該區(qū)目的層巖性、沉積相、烴源巖以及儲(chǔ)蓋特征的研究主要基于這些資料,精度和準(zhǔn)確度受到一定限制。本文以2014年所鉆位于研究區(qū)中部的探井L1井為重點(diǎn)研究對(duì)象,結(jié)合其它井資料和地震資料,采用巖心觀察、分析測(cè)試、ECS資料巖性識(shí)別、古構(gòu)造恢復(fù)、綜合研究等方法對(duì)臨河坳陷臨河組的巖性、巖相及生儲(chǔ)蓋特征開(kāi)展了進(jìn)一步研究。取得的主要認(rèn)識(shí)如下:1、本文采用兩種巖性劃分方法來(lái)研究L1井臨河組的巖性特征。其一,采用ECS資料和新的巖性解釋方法(該方法可以有效地識(shí)別出碳酸鹽巖),依據(jù)礦物成分含量進(jìn)行巖性劃分,結(jié)果表明:L1井臨河組巖性主要有石英碎屑巖和雜巖,另發(fā)育長(zhǎng)石碎屑巖、碳酸鹽巖、含膏沉積巖;其二,按傳統(tǒng)巖性劃分(依據(jù)粒度對(duì)碎屑巖巖性進(jìn)行劃分,依據(jù)礦物成分含量對(duì)碳酸鹽巖進(jìn)行劃分),結(jié)果表明:L1井臨河組巖性有泥巖、粉砂質(zhì)泥巖、白云質(zhì)泥巖、含膏質(zhì)泥巖、粉砂巖、細(xì)砂巖、中粗砂巖和含細(xì)礫粗砂巖。2、依據(jù)孢粉、微量元素及巖性特征提出,L1井臨河組為干旱半咸水-咸水的沉積環(huán)境,還原性較強(qiáng)。臨河坳陷臨河組沉積亞相類(lèi)型主要有半深湖、淺湖、濱淺湖-三角洲平原亞相。其中,深灰色細(xì)粒碳酸鹽巖的存在表明半深湖亞相在平面上具有較大的分布范圍。在區(qū)域上由L1井往西北方向泥巖變厚,地震反射層連續(xù)性變好,反映出由L1井往西北方向沉積相帶(水體)變深。3、L1井臨河組烴源巖巖性主要為深灰色、灰色泥巖,按礦物成分分類(lèi),巖性主要為雜巖、粘土巖、碳酸鹽巖與細(xì)粒石英碎屑巖。臨河組烴源巖累計(jì)厚度235m,占地層厚度的25.74%,單層厚度平均2.43m,最大12m。依據(jù)L1井56個(gè)樣品地球化學(xué)分析資料,臨河組烴源巖類(lèi)型以Ⅰ型和Ⅱ型為主,有機(jī)質(zhì)豐度大(有機(jī)碳含量達(dá)4.09%),R0在0.76%-1.06%之間。依據(jù)烴源巖的區(qū)域沉積相及埋藏幅度特征,L1井西北部烴源巖有機(jī)質(zhì)豐度會(huì)更大、類(lèi)型更好、成熟度更高,生油巖累積厚度更厚。4、根據(jù)巖石力學(xué)性質(zhì)將臨河坳陷新生界沉積巖沉積后變化分為三個(gè)階段即塑性壓實(shí)段、彈塑性壓縮段和破裂段。目前,漸新統(tǒng)臨河組沉積巖主體處于破裂段,發(fā)育中-高滲孔隙性砂巖類(lèi)、裂縫性泥質(zhì)巖類(lèi)的儲(chǔ)集層以及泥質(zhì)巖類(lèi)縫改蓋層;中新統(tǒng)沉積巖主體處于彈塑性壓縮段,發(fā)育孔隙性泥巖蓋層和孔隙性砂巖儲(chǔ)層,泥質(zhì)巖蓋層厚度和分布范圍較大;上新統(tǒng)沉積巖主體處于塑性壓實(shí)段,發(fā)育孔隙性砂巖類(lèi)儲(chǔ)層及少量的泥質(zhì)巖類(lèi)蓋層。5、綜合臨河坳陷生儲(chǔ)蓋及構(gòu)造、埋藏的特點(diǎn),建議臨河坳陷下一步的油氣勘探圍繞L1井西北部杭后斷裂開(kāi)展,該區(qū)更接近有利生油區(qū),可發(fā)育下生上儲(chǔ)式(臨河組生,中、上新統(tǒng)儲(chǔ))和自生自儲(chǔ)式(臨河組生,臨河組儲(chǔ))的生儲(chǔ)蓋組合。
[Abstract]:Linhe depression in Hetao Basin is an important area for oil and gas exploration. There are 11 drilling wells in this area, 6 wells show oil, but no industrial oil flow. Because the early drilling is mainly concentrated in the southeast of Linhe depression, the study of lithology, sedimentary facies, source rock and reservoir cap characteristics of the target layer in this area is mainly based on these data, and the accuracy and accuracy are limited to a certain extent. This paper takes L1 well drilling in the middle of the research area in 2014 as the research object, combining with other well data and seismic data, using core observation, analysis and test, lithology identification of ECS data, paleotectonic recovery. The lithology, lithofacies and reservoir-caprock characteristics of Linhe formation in Linhe depression were further studied by means of comprehensive study. The main results are as follows: 1. Two lithologic classification methods are used to study the lithologic characteristics of Linhe formation in well L1. First, ECS data and a new lithologic interpretation method (which can effectively identify carbonate rocks) are used to divide lithology according to mineral composition content. The results show that the lithology of Linhe formation in well L1 mainly consists of quartz clastic rocks and complex rocks. In addition, feldspar clastic rocks, carbonate rocks and gypsum sedimentary rocks are developed. Secondly, according to the traditional lithology (the clastic lithology is divided according to the granularity, the carbonate rock is divided according to the mineral composition content), the result shows that the lithology of Linhe formation of well L1 has mudstone, silty mudstone, dolomite mudstone, 2. According to the characteristics of sporopollen, trace elements and lithology, Linhe formation of well L1 is a depositional environment of arid brackish water and brackish water. The sedimentary subfacies of Linhe formation in Linhe depression are mainly semi-deep lake, shallow lake, littoral shallow lacustrine delta plain subfacies. The existence of dark gray fine-grained carbonate rocks indicates that the semi-deep lacustrine subfacies have a large distribution range on the plane. In the region, mudstone is thickened from well L1 to northwest and the continuity of seismic reflection layer is improved, which reflects that the sedimentary facies zone (water body) from well L1 to northwest becomes deeper. The source rocks of Linhe formation in well 3Gui L1 are mainly dark gray and grey mudstone. According to the mineral composition, the lithology is mainly composed of complex rock, clay rock, carbonate rock and fine quartz clastic rock. The accumulative thickness of source rock in Linhe formation is 235 m, the thickness of the cover layer is 25.74%, the average thickness of single layer is 2.43 m, and the maximum is 12 m. According to the geochemical analysis data of 56 samples from well L1, the source rocks of Linhe formation are mainly of type 鈪，

本文編號(hào)：2373210