扒樓溝剖面二疊系辮狀河砂體構(gòu)型與非均質(zhì)性特征

王 越， 陳世悅， 李天寶， 梁繪媛， 王 劍

(1.中國石油大學地球科學與技術學院,山東青島 266580; 2.中國石化勝利油田分公司,山東東營 257015;3.新疆油田公司實驗檢測研究院,新疆克拉瑪依 834000)

扒樓溝剖面二疊系辮狀河砂體構(gòu)型與非均質(zhì)性特征

王 越1， 陳世悅1， 李天寶1， 梁繪媛2， 王 劍3

(1.中國石油大學地球科學與技術學院,山東青島 266580; 2.中國石化勝利油田分公司,山東東營 257015;3.新疆油田公司實驗檢測研究院,新疆克拉瑪依 834000)

通過露頭實測、精細解剖與巖相分析等方法,結(jié)合巖石薄片與物性資料,對山西保德扒樓溝剖面二疊系山西組辮狀河砂體的構(gòu)型與非均質(zhì)性特征進行系統(tǒng)研究。結(jié)果表明:辮狀河主要發(fā)育河道和心灘2種成因砂體,河道砂體的垂向巖相組合為Ge-St,心灘砂體的垂向巖相組合為Ge-Sm-M-Sm-Sp-M-Sp或Ge-Sm-St-Sm-St-Sp-M-Sp;辮狀河砂體可劃分為5級構(gòu)型單元,由小到大分別是層系、層系組、心灘/河道增生單元、心灘/辮狀河道、單期河道,河道砂體由多個增生單元在垂向上加積構(gòu)成,心灘砂體由多個增生單元與串溝砂體在垂向上加積構(gòu)成,內(nèi)部發(fā)育泥質(zhì)夾層;心灘砂體物性優(yōu)于河道砂體,非均質(zhì)性相對較弱,整體可以作為優(yōu)質(zhì)儲層,而河道砂體僅在靠近河心的部位物性較好,可作為優(yōu)質(zhì)儲層;心灘砂體內(nèi)規(guī)模較大的泥質(zhì)夾層附近和河道砂體的邊部及中上部可聚集剩余油,且心灘砂體內(nèi)剩余油儲量相對河道砂體較大。

扒樓溝剖面; 辮狀河; 河道; 心灘; 砂體構(gòu)型; 非均質(zhì)性； 剩余油分布

辮狀河砂體規(guī)模大、物性好,是優(yōu)質(zhì)的油氣儲集砂體,其內(nèi)部復雜的構(gòu)型與非均質(zhì)性特征直接控制著剩余油的分布。開展砂體構(gòu)型及非均質(zhì)性研究對剩余油的預測和挖潛具有重要的意義,是提高油田采收率、最大限度開發(fā)油氣資源的關鍵所在[1-3]。近年來,眾多學者通過野外露頭[4-6]、現(xiàn)代沉積[7-11]及密井網(wǎng)資料[12-16]對辮狀河砂體構(gòu)型及內(nèi)部泥質(zhì)夾層分布規(guī)律進行了詳細研究,為砂體中剩余油的開采提供了可靠依據(jù),但是仍然存在以下兩方面問題:①目前關于辮狀河砂體構(gòu)型特征的研究多側(cè)重于心灘砂體,而河道砂體內(nèi)部構(gòu)型單元具有怎樣的幾何屬性及疊置關系,需要進一步研究;②前人針對辮狀河砂體的縱向非均質(zhì)性特征較多,而對于砂體在橫向上具有怎樣的非均質(zhì)性特征,有待進一步探索。筆者以扒樓溝剖面二疊系山西組辮狀河砂體實測和精細解剖為基礎,通過巖相分析、薄片鑒定及物性測試,定量表征辮狀河砂體內(nèi)部構(gòu)型單元的幾何屬性及橫向非均質(zhì)性特征,確定優(yōu)質(zhì)儲層發(fā)育位置,為辮狀河砂體內(nèi)剩余油預測和挖潛提供依據(jù)。

1 研究區(qū)概況

扒樓溝剖面位于山西保德縣城東南約25 km,該地區(qū)上古生界出露齊全且剖面發(fā)育良好,地層接觸關系清楚,為露頭研究創(chuàng)造了良好的條件(圖1)。二疊系山西組為目的層段,主要發(fā)育灰色—淺黃色含礫粗砂巖、中粗砂巖,夾有薄層灰黑色炭質(zhì)泥巖、泥巖及煤層,厚度一般為50～60 m,按巖性組合、沉積旋回及含煤性自下而上分為4個小層,即山22、山21和山12、山11小層。山12小層發(fā)育厚層辮狀河砂體,寬度約150 m,厚度約13 m,整體表現(xiàn)為下粗上細的正粒序結(jié)構(gòu),底部發(fā)育大型沖刷面,下部發(fā)育大型槽狀交錯層理與塊狀層理,上部發(fā)育小型槽狀交錯層理與板狀交錯層理。

圖1 研究區(qū)位置及山西組綜合柱狀圖Fig.1 Location of study area and composite histogram of Shanxi Formation

2 成因砂體

2.1 巖相類型

巖相反映了沉積體形成的水動力條件、搬運方式及沉積作用機制等[17-18],是劃分沉積微相、識別成因砂體的重要依據(jù)。通過對扒樓溝剖面山西組辮狀河露頭的巖性、粒度、沉積構(gòu)造和顏色等特征分析總結(jié),共識別出5種巖相類型(表1、圖2)。

表1 巖相類型劃分及成因解釋Table 1 Type division and genetic explantion of lithofacies

圖2 扒樓溝剖面山西組辮狀河露頭典型巖相類型Fig.2 Typical lithofacies types of braided river outcrop of Shanxi Formation in Palougou profile

2.2 成因砂體

山12小層以辮狀河砂體沉積為主,包括河道和心灘2種成因砂體,兩者在外部幾何形態(tài)、內(nèi)部結(jié)構(gòu)與巖相特征等方面存在顯著差異。

2.2.1 河 道

露頭上可見辮狀水道砂體呈底凸頂平的外部幾何形態(tài),長度約為60.5 m,厚度約為9.3 m,其巖相組合為Ge-St(表2、圖3(a))。辮狀水道底部可見明顯的沖刷面,沖刷面上發(fā)育滯留礫巖相,夾有植物莖干化石,礫石最大粒徑約為7 cm,平均粒徑約為3 cm(圖2(a));下部過渡為槽狀交錯層理中粗砂巖相,層理規(guī)模較大,層系寬約3 m,高約0.5 m(圖2(b)),上部發(fā)育槽狀交錯層理中細砂巖相,層理規(guī)模變小,層系寬度約為1.5 m,高度約為0.3 m(圖2(c)),反映了水動力條件較強,且向上逐漸減弱。

2.2.2 心 灘

心灘砂體呈底平頂凸的外部幾何形態(tài),長度約為90.8 m,厚度約為13.2 m,其巖相組合為Ge-Sm-M-Sm-Sp-M-Sp或Ge-Sm-St-Sm-St-Sp-M-Sp(表2、圖3(b)、(c))。心灘底部發(fā)育滯留礫巖相,由次棱角狀—次圓狀、分選中等、平均粒徑為1.5 cm的礫石組成,厚度一般為10～20 cm(圖2(d));下部發(fā)育塊狀層理粗砂巖,厚度約為5～6 m(圖2(e)),夾有灰綠色薄層泥巖(圖2(f)),即落淤層;上部發(fā)育槽狀交錯層理中粗砂巖相,為強水流沖裂心灘形成的沖溝沉積(圖2(g));頂部發(fā)育多組低角度下截型板狀交錯層理中細砂巖相,紋層界面傾角一般為14°～20°,層系厚度10～20 cm(圖2(h)),內(nèi)部夾有薄層灰綠色泥巖(圖2(i))。

表2 扒樓溝剖面山西組辮狀河砂體構(gòu)型特征Table 2 Architectural characteristics of braided river sand body of Shanxi Formation in Palougou profile

圖3 扒樓溝剖面山西組辮狀河砂體巖相組合垂向序列Fig.3 Lithofacies combination characteristics of braided river sand body of Shanxi Formation in Palougou profile

3 砂體構(gòu)型特征

通過對扒樓溝剖面山12小層辮狀河砂體進行詳細觀察及實測,根據(jù)砂體規(guī)模可以劃分為5級構(gòu)型單元,由小到大分別是層系、層系組、心灘/河道增生單元、心灘/辮狀河道、單期河道,分別被不同級別的界面所限定(表2)。該辮狀河砂體長度約為150 m,厚度約為13 m,走向為E-W向,近似垂直于主物源方向[19-20],其整體為一個單期河道,由1個河道砂體與1個心灘砂體側(cè)向拼接構(gòu)成(圖4)。

表3 扒樓溝剖面山西組辮狀河砂體構(gòu)型單元與界面級次劃分Table 3 Architectural elements and bounding surfacies of braided river sand body of Shanxi Formation in Palougou profile

河道砂體由3個河道增生單元在垂向上加積構(gòu)成,在增生單元的底部可見較明顯的沖刷面。下部河道增生單元寬厚比較小,呈底凸頂凹狀,發(fā)育滯留礫巖相與大型槽狀交錯層理中粗砂巖相,反映河流發(fā)展早期水動力條件較強。上部河道增生單元寬厚比較大,呈底凸頂平狀,發(fā)育小型槽狀交錯層理中細砂巖相,反映河流發(fā)展后期水動力強度減弱。

心灘砂體由若干個心灘增生單元與串溝砂體在垂向上加積構(gòu)成,內(nèi)部夾有平水期形成的細粒懸浮沉積物。心灘底部的增生單元寬度約為90 m,厚度約為4 m,發(fā)育滯留礫巖相與塊狀層理中粗砂巖相,為河流形成早期強水動力條件下粗碎屑物質(zhì)快速堆積的產(chǎn)物;上部心灘增生單元在剖面上表現(xiàn)為底平頂凸,寬度一般為12～52 m,厚度為1.5～3.2 m,寬厚比較下部增生單元減小,發(fā)育塊狀層理中粗砂巖相與板狀交錯層理中細砂巖相。串溝為平水期小規(guī)模流水在心灘頂部沖出的溝道,常分布在靠近心灘中部的位置,剖面上表現(xiàn)為底凸頂平,厚度約為2 m,寬度為19～28 m,發(fā)育槽狀交錯層理中粗砂巖相。

圖4 扒樓溝剖面山西組辮狀河砂體構(gòu)型特征與發(fā)育模式Fig.4 Architectural characteristics and development mode of braided river sand body of Shanxi Formation in Palougou profile

4 砂體非均質(zhì)性

在砂體構(gòu)型研究的基礎上,通過在河道與心灘砂體底部進行橫向連續(xù)取樣,對各砂體物性與巖性特征開展研究,分析整個辮狀河砂體的橫向非均質(zhì)性,確定優(yōu)質(zhì)儲層發(fā)育位置。

河道砂體孔隙度一般為9.66%～11.60%,平均值為10.44%,滲透率一般為(0.002 7～0.006 7)×10-3μm2,平均值為0.003 8×10-3μm2,滲透率均質(zhì)系數(shù)為0.57,變異系數(shù)為0.85。心灘砂體孔隙度一般為10.76%～12.67%,平均值為11.46%,滲透率一般為(0.006 5～0.011 9)×10-3μm2,平均值為0.008 5×10-3μm2,滲透率均質(zhì)系數(shù)為0.71,變異系數(shù)為0.48(表4)。通過對比可知心灘砂體孔隙度、滲透率明顯大于河道砂體,而且滲透率均質(zhì)系數(shù)較大、變異系數(shù)較低,表明心灘砂體物性優(yōu)于河道砂體,且非均質(zhì)性相對較弱。

河道以中細粒長石質(zhì)巖屑砂巖、中粗粒巖屑砂巖為主,從河道邊部向河心方向巖石粒度變粗,雜基含量減少,孔滲性能變好;心灘砂體巖石粒度較河道砂體有所變粗,以中粗粒巖屑砂巖、中粗粒長石質(zhì)巖屑砂巖為主,橫向上巖石粒度變化不大,雜基含量較少,孔滲性能整體較好(圖5)。結(jié)合物性與巖性特征分析可知,在辮狀河沉積中河道砂體非均質(zhì)程度較強,僅在靠近河心部位物性較好,可作為優(yōu)質(zhì)儲層;心灘砂體物性優(yōu)于河道砂體,非均質(zhì)程度相對較弱,整體可作為優(yōu)質(zhì)儲層。

表4 扒樓溝剖面山西組辮狀河道與心灘砂體物性特征Table 4 Physical properties of the braided river channel and channel bar of Shanxi Formation in Palougou profile

圖5 扒樓溝剖面山西組辮狀河道與心灘砂體物性及巖性特征對比Fig.5 Physical properties and lithology comparison of braided river channel and channel bar of Shanxi Formation in Palougou profile

5 剩余油分布預測

在河道砂體與心灘砂體之間不發(fā)育泥質(zhì)夾層,因此辮狀河砂體整體上為一個泛連通體,但兩種砂體在構(gòu)型及非均質(zhì)性特征方面存在顯著差異,導致在注水開發(fā)過程中具有不同的水驅(qū)波及特征和剩余油分布特征。河道砂體在靠近河心的部位物性較好,且在縱向上不發(fā)育泥質(zhì)夾層,因此底水和注入水容易在河心附近向上突進,造成油層快速水淹,形成強水淹層。在河道的邊部和中上部砂體物性相對較差,底水錐進和注入水速度較慢,水淹程度較低,分布有一定量的剩余油。心灘砂體物性整體較好,但內(nèi)部發(fā)育水平分布的泥質(zhì)落淤層,其對底水和注入水的垂向遮擋作用明顯,導致心灘的砂體的水淹程度低于河道砂體,在規(guī)模較大的泥質(zhì)夾層附近分布有剩余油。綜合考慮心灘砂體與河道砂體的規(guī)模、構(gòu)型特征及非均質(zhì)性特征,認為河道砂體內(nèi)剩余油儲量較小,而心灘砂體內(nèi)剩余油儲量相對較大。

6 結(jié) 論

(1)扒樓溝剖面二疊系山西組辮狀河發(fā)育河道和心灘兩種成因砂體,河道砂體在剖面上呈底凸頂平狀,長度約為60.5 m,厚度約為9.3 m,其巖相組合為Ge-St;心灘砂體在剖面上呈底平頂凸狀,長度約為90.8 m,厚度約為13.2 m,發(fā)育Ge-Sm-M-Sm-Sp-M-Sp和Ge-Sm-St-Sm-St-Sp-M-Sp兩種巖相組合類型。

(2)辮狀河砂體可劃分為5級構(gòu)型單元,由小到大分別是層系、層系組、心灘/河道增生單元、心灘/辮狀河道、單期河道。河道砂體由多個增生單元在垂向上加積構(gòu)成,增生單元自下而上寬厚比值變大。心灘砂體由多個增生單元與串溝砂體在垂向上加積構(gòu)成,心灘增生單元呈底平頂凸的外部幾何形態(tài);串溝砂體表現(xiàn)為底凸頂平的外部幾何形態(tài),常分布在靠近心灘中部的位置。

(3)河道砂體的橫向非均質(zhì)性相對較強,在其邊部的巖石粒度較細,雜基含量較高,物性較差;在靠近河心的位置,巖石粒度較粗,雜基含量較低,物性較好,可作為優(yōu)質(zhì)儲層。心灘砂體巖石粒度比河道砂體粗,儲層物性優(yōu)于河道砂體,橫向非均質(zhì)性相對較弱,整體可作為優(yōu)質(zhì)儲層。

(4)河道砂體內(nèi)水淹程度較高,剩余油儲量較小,主要分布在河道砂體的邊部和中上部;心灘砂體水淹程度相對較低,剩余油儲量相對較大,主要分布在規(guī)模較大的泥質(zhì)夾層附近。

[1] 封從軍,鮑志東,楊玲,等.三角洲前緣水下分流河道儲集層構(gòu)型及剩余油分布[J].石油勘探與開發(fā),2014,41(3):323-329. FENG Congjun, BAO Zhidong, YANG Ling, et al. Reservoir architecture and remaining oil distribution of deltaicfront underwater distributary channel[J]. Petroleum Exploration and Development,2014,41(3):323-329.

[2] 周銀邦,吳勝和,計秉玉,等. 曲流河儲層構(gòu)型表征研究進展[J].地球科學進展, 2011,26(7):695-702. ZHOU Yinbang, WU Shenghe, JI Bingyu, et al. Research progress on the characterization of fluvial reservoir architecture[J]. Advances in Earth Science, 2011,26(7):695-702.

[3] 閆百泉,張鑫磊,于利民,等.基于巖心及密井網(wǎng)的點壩構(gòu)型與剩余油分析[J].石油勘探與開發(fā),2014,41(5):597-604. YAN Baiquan, ZHANG Xinlei, YU Limin, et al. Point bar configuration and residual oil analysis based on core and dense well pattern [J]. Petroleum Exploration and Development, 2014,41(5):597-604.

[4] 陳彬濤,于興河,王天奇,等.砂質(zhì)辮狀河巖相與構(gòu)型特征:以山西大同盆地中侏羅統(tǒng)云岡組露頭為例[J].石油與天然氣地質(zhì),2015,36(1):111-117. CHEN Bintao, YU Xinghe, WANG Tianqi, et al. Lithofacies and architecture characteristics of sandy braided river deposits: a case from outcrops of the Middle Jurassic Yungang Formation in the Datong Basin, Shanxi province[J]. Oil & Gas Geology, 2015,36(1):111-117.

[5] 楊麗莎,陳彬滔,李順利,等.基于成因類型的砂質(zhì)辮狀河泥巖分布模式:以山西大同侏羅系砂質(zhì)辮狀河露頭為例[J].天然氣地球科學,2013,24(1):93-98. YANG Lisha, CHEN Bintao, LI Shunli, et al. Pattern of genesis-based mudstone distribution for sandy braided river:a case of sandy braided-river outcrop, Datong, Shanxi province, China[J].Natural Gas Geoscience, 2013,24(1):93-98.

[6] 李海燕,高陽,王延杰,等. 辮狀河儲集層夾層發(fā)育模式及其對開發(fā)的影響:以準噶爾盆地風城油田為例[J]. 石油勘探與開發(fā),2015,42(2):364-373. LI Haiyan, GAO Yang, WANG Yanjie, et al. Intercalation pattern and its impact on development of braided river: a case of Fengcheng Oilfield, Junggar Basin, NW China[J]. Petroleum Exploration and Development, 2015,42(2):364-373.

[7] 廖保方,張為民,李列,等.辮狀河現(xiàn)代沉積研究與相模式:中國永定河剖析[J]. 沉積學報,1998,16(1):34-39. LIAO Baofang, ZHANG Weimin, LI Lie, et al. Study on modern deposit of a braided stream and faces model: taking the Yongding River as an example[J]. Acta Sedimentologica Sinica, 1998,16(1):34-39.

[8] BRISTOW C S. Sedimentary structure exposed in bar tops in the Brahmaputra River, Bangladesh[C]//Best J L, Bristow C S. Braided rivers: Geological Society of London special publication 75. London: The Geological Society of London, 1993:277-289.

[9] THORNE C R, RUSSEL A P G, ALAM M K. Planform pattern and channel evolution of the Brahmaputra River, Bangladesh[M]//Best J L, Bristow C S. Braided rivers: Geological Society of London special publication 75. London: The Geological Society of London, 1993:257-276.

[10] ASHWORTH P J, BEST J L, RODEN J E, et al. Morphological evolution and dynamics of a large, sand braid-bar, Jamuna River, Bangladesh[J]. Sedimentology, 2000,47(3):533-555.

[11] BEST J L, ASHWORTH P J, BRISTOW C S, et al. Three-dimensional sedimentary architecture of a large,mid-channel sand braid bar, Jamuna River, Bangladesh[J]. Journal of Sedimentary Research, 2003,73(4):516-530.

[12] 劉鈺銘,侯加根,王連敏,等.辮狀河儲層構(gòu)型分析[J].中國石油大學學報(自然科學版),2009,33(1):7-11. LIU Yuming, HOU Jiagen, WANG Lianmin, et al. Architecture analysis of braided river reservoir[J].Journal of China University of Petroleum(Edition of Natural Science),2009,33(1):7-11.

[13] 劉鈺銘,侯加根,宋保全,等.辮狀河厚砂層內(nèi)部夾層表征:以大慶喇嘛甸油田為例[J].石油學報,2011,32(5):836-841. LIU Yuming, HOU Jiagen, SONG Baoquan, et al. Characterization of interlayers within braided-river thick sandstones: a case studyon the Lamadian Oilfield in Daqing[J]. Acta Petrolei Sinica,2011,32(5):836-841.

[14] 牛博,高興軍,趙應成,等.古辮狀河心灘壩內(nèi)部構(gòu)型表征與建模:以大慶油田薩中密井網(wǎng)區(qū)為例[J]. 石油學報,2015,36(1):89-100. NIU Bo, GAO Xingjun, ZHAO Yingcheng, et al. Architecture characterization and modeling of channel bar in paleo-braided river: a case of sandy of dense well pattern area of Sazhong in Daqing Oilfield[J].Acta Petrolei Sinica,2015,36(1):89-100.

[15] 趙倫,王進財,陳禮,等.砂體疊置結(jié)構(gòu)及構(gòu)型特征對水驅(qū)規(guī)律的影響:以哈薩克斯坦南圖爾蓋盆地Kumkol油田為例[J].石油勘探與開發(fā),2014,41(1):86-94. ZHAO Lun, WANG Jincai, CHEN Li, et al. Influences of sandstone superimposed structure and architecture on waterfloodingmechanisms: a case study of Kumkol Oilfield in the South Turgay Basin, Kazakhstan[J]. Petroleum Exploration and Development, 2014,41(1):86-94.

[16] 袁新濤,吳向紅,張新征,等.蘇丹Fula油田辮狀河儲層內(nèi)夾層沉積成因及井間預測[J]. 中國石油大學學報(自然科學版),2013,37(1):8-12,34. YUAN Xintao, WU Xianghong, ZHANG Xinzheng, et al. Sedimentary origin and interwell prediction of interbeds in braided river reservoir,Fula Oilfield in Sudan[J]. Journal of China University of Petroleum(Edition of Natural Science), 2013,37(1):8-12,34.

[17] 陳彬滔,于興河,潘樹新,等.準噶爾盆地南緣頭屯河組曲流河沉積特征與成因砂體對比方法[J].天然氣地球科學,2013,24(6):1132-1139. CHEN Bintao, YU Xinghe, PAN Shuxin, et al. Sedimentary characteristics and sedimentogenic-based sandbodies correlation methods of meandering river in Toutunhe Formation, southern margin of Junggar Basin[J]. Natural Gas Geoscience, 2013,24(6):1132-1139.

[18] 譚程鵬,于興河,李勝利,等.辮狀河-曲流河轉(zhuǎn)換模式探討:以準噶爾盆地南緣頭屯河組露頭為例[J].沉積學報,2014,32(3):450-458. TAN Chengpeng, YU Xinghe, LI Shengli, et al. Discussion on the model of braided river transform to meandering river: as an example of Toutunhe Formation in Southern Junggar Basin[J]. Acta Sedimentologica Sinica, 2014,32(3):450-458.

[19] 王國茹. 鄂爾多斯盆地北部上古生界物源及層序巖相古地理研究[D]. 成都：成都理工大學, 2011. WANG Guoru. The study of sources and sequence-lithofaces Palaeogeography of Upper Palaeozoic, Northern Ordos[D].Chengdu: Chengdu University of Technology,2011.

[20] 李明瑞. 鄂爾多斯盆地北部上古生界主要含氣砂體沉積特征及儲層控制因素研究[D].成都:成都理工大學,2011. LI Mingrui. Depositional character and control factors of reservoir sandbody in major gas-bearing interval of upper Paleozoic in North Ordos Basin[D]. Chengdu: Chengdu University of Technology,2011.

(編輯 徐會永)

Braided river sand body architecture and heterogeneity of Permian in Palougou outcrop

WANG Yue1, CHEN Shiyue1, LI Tianbao1, LIANG Huiyuan2, WANG Jian3

(1.School of Geosciences in China University of Petroleum, Qingdao 266580, China;2.ShengliOilfield,SINOPEC,Dongying257015,China;3.ExperimentalTestingInstituteofXinjiangOilfield,Karamay834000,China)

Through field measurement, sand body anatomy, lithofacies analysis, and with the aid of thin sections and physical data, the architecture and heterogeneity characteristics of the braided river sand bodies of Shanxi Formation of Permian in the Palougou profile in Baode county, Shanxi province, were systematically studied. The results show that two kinds of genetic sand bodies, channel and channel bar are mainly developed in braided rivers. The vertical lithofacies combinations in channel sand body and channel bar sand body are Ge-St and Ge-Sm-M-Sm-Sp-M-Sp or Ge-Sm-St-Sm-St-Sp-M-Sp, respectively; Braided river sand bodies can be further divided into five levels of architectural elements, which are bed, bed set, channel bar/channel accretion, channel bar/braided channel, and braided river from small to large. Channel sand body is usually composed of several accretions superimposed vertically, while channel bar sand body is composed of several accretions and chute sand bodies superimposed vertically, with mud layers in it. Channel bar sand body has better physical properties and weaker heterogeneity than channel sand body, and therefore, the whole channel bar can be high quality reservoir. On the other hand, channel sand body only has good physical properties near the river center which may become potential reservoir. Remaining oil mainly accumulates near large scales of mud layers in the channel bar, and in the side and upper part of the channel sand body, but with large deposition potentials in the channel bar.

Palougou profile; braided river; channel; channel bar; sand body architecture; heterogeneity; remaining oil distribution

2016-06-05

“十二五”國家油氣重大專項(2011ZX05013-002)

王越(1988-)，男，博士研究生，研究方向為層序地層學及沉積學。E-mail：620788364@qq.com。

1673-5005(2016)06-0001-08

10.3969/j.issn.1673-5005.2016.06.001

TE 121.3

A

王越,陳世悅,李天寶,等. 扒樓溝剖面二疊系辮狀河砂體構(gòu)型與非均質(zhì)性特征[J].中國石油大學學報(自然科學版),2016,40(6):1-8.

WANG Yue, CHEN Shiyue, LI Tianbao, et al. Braided river sand body architecture and heterogeneity of Permian in Palougou outcrop [J]. Journal of China University of Petroleum(Edition of Natural Science),2016,40(6):1-8.