葛海霞，張枝煥，閔 偉

(1．中國石油大學(xué) 地球科學(xué)學(xué)院，油氣資源與探測國家重點(diǎn)實(shí)驗(yàn)室，北京 102249；2.中國石化 勝利油田石油開發(fā)中心，山東 東營 257015)

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渤海灣盆地青東凹陷古近系原油地球化學(xué)特征及油源分析

葛海霞1，張枝煥1，閔 偉2

(1．中國石油大學(xué) 地球科學(xué)學(xué)院，油氣資源與探測國家重點(diǎn)實(shí)驗(yàn)室，北京 102249；2.中國石化 勝利油田石油開發(fā)中心，山東 東營 257015)

生物降解油；生物標(biāo)志物；油源對比；青東凹陷；濟(jì)陽坳陷；渤海灣盆地

1 區(qū)域地質(zhì)概況及樣品分布

青東凹陷為位于濟(jì)陽坳陷東部、郯廬斷裂帶西側(cè)的新生代陸相斷陷湖盆，在太古界結(jié)晶變質(zhì)巖之上發(fā)育了古生界、中生界、新生界及第四系等沉積巖系，目前已鉆至中生界，古近系孔店組、沙河街組，新近系館陶組、明化鎮(zhèn)組及第四系平原組。沙三下和沙四上亞段為烴源巖和油氣分布主要層位。凹陷存在常規(guī)原油和稠油，常規(guī)原油分布在深洼地帶，埋深大于2 000 m；稠油分布在凹陷邊緣，埋深小于2 000 m。原油在不同深度和部位遭受生物降解程度不同，過渡帶(青東4井)達(dá)到8級，西部斜坡帶(青東17井)為6級，青東5井區(qū)為2級[6](圖1)。

2 原油地球化學(xué)特征及成因類型劃分

2.1 Ⅰ類原油

圖1 渤海灣盆地濟(jì)陽坳陷青東凹陷區(qū)域構(gòu)造位置及樣品分布據(jù)詹潤等[17]，2012，有修改。

表1 渤海灣盆地濟(jì)陽坳陷青東凹陷古近系典型原油族組分、飽和烴及芳烴參數(shù)指示成熟度特征

注：F1= (3-MP+2-MP)/(1-MP+2-MP+3-MP+9-MP);F2=2-MP/(1-MP+2-MP+3-MP+9-MP);RF1=2.242F1-0.166;RF2=3.73F2-0.112。

圖2 渤海灣盆地濟(jì)陽坳陷青東凹陷古近系各類原油部分生物標(biāo)志化合物質(zhì)量色譜TT表示三環(huán)萜烷； TeT表示四環(huán)萜烷

2.2 Ⅱ類原油

2.3 Ⅲ 類原油

2.4 Ⅳ類原油

3 烴源巖地球化學(xué)特征及類型劃分

3.1 有機(jī)地球化學(xué)參數(shù)特征

青東凹陷主力烴源巖為沙三下亞段和沙四上亞段，均在凹陷中北部深洼達(dá)到最大厚度。沙四上亞段為半干旱條件下的濱淺湖和半深湖沉積，為暗色泥巖夾油頁巖、白云巖；沙三中下亞段暗色泥巖為穩(wěn)定的深湖—半深湖相沉積，沉積厚度和分布范圍變小。烴源巖處于低熟—成熟階段，成熟門限約為2 250 m；有機(jī)質(zhì)類型以Ⅰ-Ⅱ型為主，有機(jī)質(zhì)豐度均達(dá)到好的烴源巖標(biāo)準(zhǔn)(表2)。

3.2 生物標(biāo)志物組成特征及類型劃分

表2 渤海灣盆地濟(jì)陽坳陷青東凹陷與青南洼陷沙河街組烴源巖主要地球化學(xué)特征

圖3 渤海灣盆地濟(jì)陽坳陷青東凹陷烴源巖部分生物標(biāo)志化合物譜圖TT表示三環(huán)萜烷； TeT表示四環(huán)萜烷

4 油源分析

4.1 Ⅰ類原油來源分析

Ⅰ類原油與A類烴源巖均具有姥鮫烷優(yōu)勢，β-胡蘿卜烷、伽馬蠟烷、C24四環(huán)萜烷及升藿烷相對含量低(圖4)。飽和烴和芳烴成熟度參數(shù)計(jì)算結(jié)果吻合，皆顯示原油為成熟油(表1)，推測Ⅰ類原油來源于凹陷沙三下亞段成熟烴源巖。

4.2 Ⅱ類原油來源分析

4.3 Ⅲ 類原油來源分析

4.4 Ⅳ類原油來源分析

圖4 渤海灣盆地濟(jì)陽坳陷青東凹陷原油與烴源巖部分生物標(biāo)志化合物參數(shù)特征

5 結(jié)論

(1)青東凹陷分布有4類原油(Ⅰ、Ⅱ、Ⅲ和Ⅳ)，Ⅰ類原油主要分布在凹陷中北部沙三下亞段儲層中(青東30井、青東12井)，Ⅱ類原油主要分布在凹陷西南部斜坡帶的沙四上亞段儲層中(5-2-斜11井)，Ⅲ類原油主要分布在凹陷西北部斜坡帶的沙四上亞段儲層中(青東17井、青東23井)，Ⅳ類原油分布在青東—青南過渡帶的沙三下亞段及沙四上亞段儲層中(青東11井、青東4井)。

(2)研究區(qū)烴源巖包括2大類3小類(A、B1和B2)。油源分析表明，Ⅰ類原油來自凹陷中北部深洼的沙三下亞段成熟烴源巖(A類)；Ⅱ類原油來自凹陷南部沙四上亞段烴源巖(B2類)；Ⅲ類原油來源于凹陷中北部洼陷沙四上亞段烴源巖(B1類)；Ⅳ類原油來源于東營凹陷青南洼陷沙四上亞段烴源巖，其中青東8井原油應(yīng)有青東凹陷南部沙四上亞段烴源巖的貢獻(xiàn)。

[1] 張水昌,梁狄剛,黎茂穩(wěn),等.分子化石與塔里木盆地油源對比[J].科學(xué)通報(bào),2002,47(S1):16-23.

Zhang Shuichang,Liang Digang,Li Maowen,et al.Molecular fossils and oil-source rock correlations in Tarim Basin,NW China[J].Chinese Science Bulletin,2002,47(S1):20-27.

[2] 王傳剛,王鐵冠,張衛(wèi)彪,等.塔里木盆地北部塔河油田原油分子地球化學(xué)特征及成因類型劃分[J].沉積學(xué)報(bào), 2006,24(6):901-909.

Wang Chuangang,Wang Tieguan,Zhang Weibiao,et al.Molecular geochemistry and classifications of genetic types of petroleum from Tahe oilfield of the northern Tarim Basin[J].Acta Sedimentologica Sinica,2006,24(6):901-909.

[3] Jiang Zhusheng,Fowler M G,Lewis C A,et al.Polycyclic alkanes in a biodegraded oil from the Kelamayi oilfield,northwestern China[J].Organic Geochemistry,1990,15(1):35-46.

[4] Seifert W K,Moldowan J M,Demaison G J.Source correlation of biodegraded oils[J].Organic Geochemistry,1984,6:633-643.

[5] Fazeelat T,Asif M,Jalees M I,et al.Source correlation between biodegraded oil seeps and a commercial crude oil from the Pun-jab Basin,Pakistan[J].Journal of Petroleum Science and Engineering,2011,77(1):1-9.

[6] Peters K E,Moldowan J M.The biomarker guide:Interpreting mole-cular fossils in petroleum and ancient sediments[M].Englewood Cliffs:Prentice Hall,1993:100-170.

[7] 馬安來,張水昌,張大江,等.生物降解原油地球化學(xué)研究新進(jìn)展[J].地球科學(xué)進(jìn)展,2005,20(4):449-454.

Ma Anlai,Zhang Shuichang,Zhang Dajiang,et al.The advances in the geochemistry of the biodegraded oil[J].Advance in Earth Science,2005,20(4):449-454.

[8] 國朋飛,何生,朱書奎,等.利用三環(huán)萜烷對比泌陽凹陷生物降解油油源[J].石油實(shí)驗(yàn)地質(zhì),2015,37(1):80-87.

Guo Pengfei,He Sheng,Zhu Shukui,et al.Application of tricyclic terpanes in biodegraded oil-source correlation in Biyang Sag[J].Petroleum Geology & Experiment,2015,37(1):80-87.

[9] 李水福,胡守志,何生,等.泌陽凹陷北部斜坡帶生物降解油的油源對比[J].石油學(xué)報(bào),2010, 31(6):946-951.

Li Shuifu,Hu Shouzhi,He Sheng,et al.Oil-source correlation for biodegraded oils in the north slope of the Biyang Depression[J].Acta Petrolei Sinica,2010,31(6):946-951.

[10] Moore R J,Thorpe R E,Mohaney C L.Isolation of methylchrysene from petroleum[J].Journal of the American Chemistry Society,1953,75(9):2259.

[11] Laflamme R E,Hites R A.The global distribution of polycyclic aromatic hydrocarbons in recent sediments[J].Geochimica et Cosmochimica Acta,1978,42(3):289-303.

[12] Laflamme R E,Hites R A.Tetra- and pentacyclic,naturally-occurring,aromatic hydrocarbons in recent sediments[J].Geochimica et Cosmochimica Acta,1979,43(10):1687-1691.

[13] Grice K,Nabbefeld B,Maslen E.Source and significance of selected polycyclic aromatic hydrocarbons in sediments (Hovea-3 well,Perth Basin,Western Australia) spanning the Permian-Triassic boundary[J].Organic Geochemistry,2007,38(11):1795-1803.

[14] 王巖.近海沉積物中幾種多環(huán)芳烴的生物降解研究[D].青島:中國海洋大學(xué),2011.

Wang Yan.A study on biodegradation of several PHAs in estuary sediment[D]. Qingdao:Chinese Marine University,2011.

[15] Garrigues P,De Sury R,Angelin M L,et al.Relation of the methylated aromatic hydrocarbon distribution pattern to the maturity of organic matter in ancient sediments from the Mahakam delta[J].Geochimica et Cosmochimica Acta,1988,52(2):375-384.

[16] Kruge M A.Determination of thermal maturity and organic matter type by principal components analysis of the distributions of polycyclic aromatic compounds[J].International Journal of Coal Geology,2000,43(1/4):27-51.

[17] 詹潤,朱光有.濟(jì)陽坳陷青東凹陷基底斷裂復(fù)活規(guī)律和方式[J].地質(zhì)論評,2012,58(5):816-828.

Zhan Run,Zhu Guangyou.Reactivity features and patterns of basement faults in the Qingdong Sag,Jiyang Depression[J].Geological Review,2012,58(5):816-828.

[18] Philp R P.Correlation of crude oils from the San Jorges Basin,Argentina[J].Geochimica et Cosmochimica Acta,1983,47(2):267-275.

[19] 米敬奎,張水昌,陳建平,等.塔北地區(qū)原油碳同位素組成特征及影響因素[J].石油勘探與開發(fā),2010,37(1):21-25.

Mi Jingkui,Zhang Shuichang,Chen Jianping,et al.Carbon isotopic compositions and its effect factors of oil from northern Tarim Basin[J].Petroleum Exploration and Development,2010,37(1):21-25.

[20] 王大銳,董愛正,蔡笛.吐哈盆地侏羅系原油單體烴系列碳同位素研究[J].石油勘探與開發(fā),1997,24(2):19-21.

Wang Dayue,Dong Aizheng,Cai Di.A stable carbon isotope research on the hydrocarbon manomer series molecules in crude oils and extracts of the Jurassic in Turpan-Hami Basin[J].Petroleum Exploration and Development,1997,24(2):19-21.

[21] 趙孟軍,黃第藩.不同沉積環(huán)境生成的原油單體烴碳同位素分布特征[J].石油實(shí)驗(yàn)地質(zhì),1995,17(2):171-179.

Zhao Mengjun,Huang Difan.Carbon Isotopic distributive characteristics of crude oil monomers produced in different sedimentary environments[J].Experiment Petroleum Geology,1995,17(2):171-179.

[22] Kvalheim O M,Christy A A,Telns N,et al.Maturity determination of organic matter in coals using the methylphenanthrene distribution[J].Geochimica et Cosmochimica Acta,1987,51(7):1883-1888.

[23] 霍秋立,李振廣,付麗,等.烷基二苯并噻吩的分布與有機(jī)質(zhì)成熟度關(guān)系的探討[J].大慶石油地質(zhì)與開發(fā),2008,27(2):32-35.

Huo Qiuli,Li Zhenguang,Fu Li,et al.Study on the correlation of methyldibenzothiophenes distribution and organic maturity[J].Petroleum Geology & Oilfield Development in Daqing,2008,27(2):32-35.

[24] 王鐵冠,鐘寧寧,侯讀杰,等.低熟油氣形成機(jī)理與分布[M].北京:石油工業(yè)出版社,1995.

Wang Tieguan,Zhong Ningning,Hou Dujie,et al.Genetic mechanism and occurrence of immature hydrocarbon[M].Beijing:Petroleum Industry Publishing House,1995.

[25] 徐永昌,沈平,劉文匯,等.未熟—低熟油的同位素組成特征及判識標(biāo)志[J].科學(xué)通報(bào),2001,46(10):867-872.

Xu Yongchang,Shen Ping,Liu Wenhui,et al.Isotopic composition characteristics and identification of immature and lowmature oils[J].Chinese Science Bulletin,2001,46(22):1923-1929.

[26] 曾凡剛,妥進(jìn)才,李原,等.百色盆地低熟油的地球化學(xué)特征及成因機(jī)制[J].沉積學(xué)報(bào),1998,16(1):92-97.

Zeng Fangang,Tuo Jincai,Li Yuan,et al.Geochemical characteristics and genetic mechanism of immature oils from Baize Basin[J].Acta Sedimentologica Sinica,1998,16(1):92-97.

(編輯 黃 娟)

Geochemical characteristics and oil-source correlation of Paleogene oils in Qingdong Sag, Bohai Bay Basin

Ge Haixia1, Zhang Zhihuan1, Min Wei2

(1.StateKeyLaboratoryofPetroleumResourceandProspecting,SchoolofGeosciences,ChinaUniversityofPetroleum,Beijing102249,China; 2.PetroleumDevelopmentInstituteofSINOPECShengliOilfieldCompany,Dongying,Shandong257015,China)

Biodegraded oils have been discovered in the Qingdong Sag, Jiyang Depression, Bohai Bay Basin. On the basis of the geochemical characteristics of source rocks and crude oils, the less affected C29hopane, is chosen to calculate biomarker parameters, includingβ-carotane/(2×C29hopanes), gammacerane/(2×C29hopanes). The tricyclic terpane parameters (2×C24tetracyclic terpane)/(C26tricyclic terpanes), (2×C19)/(C28+C29) tricyclic terpanes and chrysene/phenanthrene, combined with 4-methylsteranes and carbon isotopes. Crude oils in the Qingdong Sag were divided into 4 types (Ⅰ, Ⅱ, Ⅲ, Ⅳ), while source rocks were divided into 3 types (A, B1, B2). Crude oils of type I derived from mature source rocks (type A) in the lower part of the third member of Shahejie Formation in the northern part of the sag. Crude oils of type Ⅱ were sourced from rocks (type B2) in the upper part of the fourth member of Shahejie Formation in the southern part of the sag. Crude oils of type Ⅲ were derived from type B1source rocks in the upper part of the fourth member of Shahejie Formation in the central and northern parts of the sag. Crude oils of type Ⅳ were sourced from rocks in the upper part of the fourth member of Shahejie Formation in the Qingnan Sag. Oils in well QD-8 partially originated from source rocks in the southern part of the Qingdong Sag.

biodegraded oils; biomarker; oil-source correlation; Qingdong Sag; Jiyang Depression; Bohai Bay Basin

1001-6112(2017)03-0383-07

10.11781/sysydz201703383

2016-12-21；

2017-04-05。

葛海霞 (1987—)，女，在讀博士，主要研究方向?yàn)橛蜌獾厍蚧瘜W(xué)。E-mail：lily6059.com@163.com。

國家科技重大專項(xiàng)項(xiàng)目(2016ZX05049-006-08HZ)資助。

TE122.114

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