伊拉克南部白垩系Mishrif组碳酸盐缓坡潮道沉积特征

doi:10.11743/ogg20200611

摘要/Abstract

摘要：

白垩系Mishrif组是伊拉克南部碳酸盐岩主力产层，属于典型的碳酸盐缓坡沉积，其中内缓坡高能滩相是优质储层最发育的部位。通过对伊拉克南部多个油田资料深入分析，发现Mishrif组中普遍存在有潮道沉积特征的优质储层，且多数潮道沉积在过去被当作另一种滩相沉积。笔者综合大量的岩心、铸体薄片、测井以及地震资料分析后，证实这部分储层为潟湖环境中潮道沉积，其分布广泛，是具有代表性的沉积亚相。潮道沉积岩石颗粒分选、磨圆较好，发育层理构造，粒级向上表现为正韵律或均质特征，对应为“钟形”或“箱形”测井响应特征以及弱波峰夹层地震响应特征，平面上呈北东-南西向条带状分布，整体上表现为由北东向南西迁移的特征。该研究说明碳酸盐岩地层中也发育成规模的潮道沉积，对缓坡背景下沉积模式研究是重要发现和补充。碳酸盐缓坡潮道的认识也为储层预测提供了新思路，进而为该类油藏开发方案设计与调整提供地质基础。

关键词: 潮道, 碳酸盐缓坡, Mishrif组, 沉积模式, 白垩系, 伊拉克

Abstract:

The Cretaceous Mishrif Formation is a major carbonate pay zone in southern Iraq and characterized by typical carbonate ramp deposition, in which high-energy deposits of shoal facies serve to develop the best reservoirs.Further analysis of data from oilfields in southern Iraq reveals high-quality reservoirs in tidal channels of the Mishrif Formation that were previously mistaken for shoal facies.An integrated analysis of cores, casting thin sections, log and seismic data confirms that these reservoirs are indeed of tidal channel facies in lagoon environment.The tidal channel facies is widely distributed as a representative sedimentary subfacies in the area.The sediments of the facies contain grains of good sorting and rounding, and well-developed beddings with grain size showing upward positive rhythmic or homogeneous characteristics, corresponding to "bell-" or "box-shaped" log and seismic responses of weak peak interlayer.On a map view, the facies shows a banded N-SW-trending distribution characterized by an overall shifting from northeast to southwest.This study reveals that large-scale deposits of tidal channel facies are also developed in carbonate strata, a new founding that may serve as an important supplement to the sedimentary model of carbonate ramps.The understanding of carbonate ramps of tidal channel facies also sheds light on reservoir prediction and thereby lays a geological foundation for the design and adjustment of development schemes.

Key words: tidal channel facies, carbonate ramp, Mishrif Formation, sedimentary model, Cretaceous, Iraq

中图分类号:

TE121.3

毛先宇,宋本彪,韩如冰,等. 伊拉克南部白垩系Mishrif组碳酸盐缓坡潮道沉积特征[J]. 石油与天然气地质, 2020, 41(6): 1233-1243, 1256. doi: 10.11743/ogg20200611 Xianyu Mao,Benbiao Song,Rubing Han,et al. Depositional characteristics of tidal channel facies in carbonate ramp of the Cretaceous Mishrif Formation in southern Iraq[J]. Oil & Gas Geology, 2020, 41(6): 1233-1243, 1256. doi: 10.11743/ogg20200611

图/表 11

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伊拉克南部Mishrif组岩相图版 a. R1井,岩心,埋深2 406.55~2 406.75 m，含泥质条带的泥晶灰岩，岩石呈灰白色，可见大量的黑色、束状泥质条带，岩石以泥晶基质为主，可见底栖有孔虫、浮游有孔虫，偶见白云岩化作用，孔隙不发育(a1, a2为铸体薄片，埋深2 406.69 m); b. R2井，岩心,埋深2 441.75~2 441.95 m，铸体薄片。2 441.90 m偶含硅质结核的以棘皮、有孔虫为主的粒泥灰岩；岩石呈棕色，局部发育溶蚀孔，垂直溶蚀缝以及缝合线构造，偶见结核，结核颜色随着有机质含量降低可为灰白色，可见轻微泥质条带；生物碎屑以棘皮类、底栖有孔虫类为主，偶见双壳类，非骨架碎屑以球粒为主，局部发生白云岩化作用，胶结中等，发育铸模孔、粒间溶孔；c. R2井，岩心，埋深2 390~2 390.2 m，铸体薄片2 390.05 m，Φ为18.5%，K为4.1×10-3 μm2，钙白色以底栖有孔虫类生屑为主的粒泥灰岩，岩石整体呈钙白色，胶结作用强，可见黑色泥质条带以及缝合线构造，局部发生白云岩化作用；岩石碎屑主要为底栖有孔虫，以蜂巢虫、栗孔虫为代表，还包含大量自形或半自形细晶白云岩颗粒，发育残余铸模孔；d. R2井，岩心，埋深2 438.78~2 438.98 m，铸体薄片；2 438.95 m，Φ为28.2%；K为59×10-3 μm2。富含厚壳蛤/双壳类/棘皮类生屑泥粒灰岩或颗粒灰岩；岩石呈棕色，无明显层理，肉眼可见细小白色介壳；可见大量棘皮类、底栖有孔虫类、双壳类生物碎屑，棘皮类碎屑发育共轴次生加大胶结物，发育较大规模的铸模孔以及粒间溶孔；e. R2井，岩心，埋深2 413.85~2 414.05 m，铸体薄片；2 413.95 m，Φ为15.1%；K为3.3×10-3 μm2。黄灰相间以底栖有孔虫类生屑为主粒泥灰岩；岩石呈深黄色与灰白色相间的斑块状，这是由于灰白色沉积的胶结作用强，物性差，保含油气性差，而深黄色沉积物具有一定的孔渗性而被油气沾染，可见由于被粘土或有机质充填呈深灰色马尾状的束状缝，溶蚀洞、缝较为发育；生物以底栖有孔虫为主，可见细小双壳类碎屑，白云岩较为发育，呈自形或半自形细晶形态，孔隙以铸模孔为主，较岩相C更为发育；f. R3井，岩心，埋深2 320.87~2 321.07 m，铸体薄片，2 321.04 m，Φ为24.9%，K为111×10-3 μm2。以厚壳蛤生屑为主颗粒灰岩或砾屑灰岩，岩石溶蚀孔洞十分发育，肉眼可见大量厘米级白色贝壳状的厚壳蛤；岩石组分主要为厘米级厚壳蛤碎屑，颗粒分选、磨圆差，无规律堆积，极少见白云岩化作用，孔隙发育，主要为粒间溶孔和铸模孔"

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参考文献 27

1	BP.Statistical review of world energy[R/OL].[2019-06-19].https://www.bp.com/en/global/corporate/energy-economics/statistical-review-of-world-energy.htm.
2	Alsharhan A S , Nairn A E M . Sedimentary basins and petroleum geology of the Middle East[M]. Amsterdam: Elsevier Science, 1997: 1- 942.
3	Aqrawi A A M , Goff J C , Horbury A A , et al. The petroleum geology of Iraq[M]. UK: Scientific Press Ltd, 2010.
4	Sharland P R , Archer R , Casey D M , et al. Arabian plate sequence stratigraphy[M]. Manama: Gulf PetroLink, 2001.
5	Wilson J L . Carbonate facies in geologic history[M]. Berlin: Springer Verlag, 1975: 348- 374.
6	Read J F . Carbonate platforms of passive (extensional) continental margins:Types, characteristics and evolution[J]. Tectonophysics, 1982, 81 (3): 195- 212.
7	Burchette T P , Wright V P . Carbonate ramp depositional systems[J]. Sedimentary Geology, 1992, 79, 3- 57. doi: 10.1016/0037-0738(92)90003-A
8	Flügel E . Microfacies of carbonate rocks:analysis, interpretation and application (Second Edition)[M]. Berlin: Springer-Verlag, 2010.
9	Jordan C F, Connally T C, Vest H A.Middle Cretaceous carbonates of the Mishrif Formation, Fateh field, offshore Dubai[C]//RoehlP O, Choquette P W.Carbonate petroleum reservoirs, New York: Springer-Verlag, 1985: 426-442.
10	Alsharhan A S , NairnA E M . A review of the Cretaceous formations in the Arabian Peninsula and Gulf-part II:Mid-Cretaceous (Wasia Group) stratigraphy and paleo-geography[J]. Journal of Petroleum Geology, 1988, 11, 89- 112. doi: 10.1111/j.1747-5457.1988.tb00803.x
11	Alsharhan A S, Nairn A E M.Carbonate platform models of Arabian Cretaceous reservoirs[C]//Simo J A T, Scott R W, Masse J P.Cretaceous carbonate platforms, AAPG Memoir, 1993, 56: 173-184.
12	Aqrawi A A M , TehniG A , SherwaniG H , et al. Mid-Cretaceous rudist-bearing carbonates of the Mishrif Formation:An important reservoir sequence in the Mesopotamian Basin, Iraq[J]. Journal of Petroleum Geology, 1998, 21 (1): 57- 82. doi: 10.1111/j.1747-5457.1998.tb00646.x
13	Aqrawi A A M, MahdiT A, SherwaniG H, et al.Characterisation of the Mid-Cretaceous Mishrif reservoir of the southern Mesopotamian Basin, Iraq[C]//AAPG GEO 2010 Middle East Geoscience Conference & Exhibition Manama, Bahrain, March 7-10, 2010.
14	Mahdi T A , Aqrawi A A M , Horbury A D , et al. Sedimentological characterization of the Mid-Cretaceous Mishrif reservoir in southern Mesopotamian Basin, Iraq[J]. Geoarabia, 2013, 18 (1): 139- 174.
15	Mahdi T A , Aqrawi A A M . Sequence stratigraphic analysis of the mid-Cretaceous Mishrif Formation, southern Mesopotamian Basin, Iraq[J]. Journal of Petroleum Geology, 2014, 37 (3): 287- 312. doi: 10.1111/jpg.12584
16	王君, 郭睿, 赵丽敏, 等. 颗粒滩储集层地质特征及主控因素——以伊拉克哈法亚油田白垩系Mishrif组为例[J]. 石油勘探与开发, 2016, 43 (3): 367- 377.
	Wang Jun , Guo Rui , Zhao Limin , et al. Geological features of grain bank reservoirs and the main controlling factors:A case study on Cretaceous Mishrif Formation, Halfaya Oilfield, Iraq[J]. Petroleum Exploration and Development, 2016, 43 (3): 367- 377.
17	姚子修, 刘航宇, 田中元, 等. 伊拉克西古尔纳油田中白垩统Mishrif组碳酸盐岩储层特征及主控因素[J]. 海相油气地质, 2018, 23 (2): 59- 69.
	Yao Zixiu , Liu Hangyu , Tian Zhongyuan , et al. Characteristics and main controlling factors of carbonate reservoir of the Middle Cretaceous Mishrif Formation in the West Qurna Oilfield, Iraq[J]. Marine Origin Petroleum Geology, 2018, 23 (2): 59- 69.
18	刘航宇, 田中元, 刘波, 等. 中东地区巨厚强非均质碳酸盐岩储层分类与预测——以伊拉克W油田中白垩统Mishrif组为例[J]. 石油学报, 2019, 40 (6): 677- 691.
	Liu Hangyu , Tian Zhongyuan , Liu Bo , et al. Classification and prediction of giant thick strongly heterogeneous carbonate reservoirs in the Middle East area:a case study of Mid-Cretaceous Mishrif Formation in the W oilfield of Iraq[J]. Acta Petrolei Sinica, 2019, 40 (6): 677- 691.
19	伏美燕, 赵丽敏, 段天向, 等. 伊拉克HF油田Mishrif组厚壳蛤滩相储层沉积与早期成岩特征[J]. 中国石油大学学报(自然科学版), 2016, 40 (5): 1- 9.
	Fu Meiyan , Zhao Limin , Duan Tianxiang , et al. Reser-voir and early diagenesis characteristics of rudist shoal of MishrifFormationin HF Oilfield of Iraq[J]. Journal of China University of Petroleum, 2016, 40 (5): 1- 9.
20	Burchette T P.Mishrif Formation (Cenomanian-Turonian), southern Arabian Gulf: carbonate platform growth along a cratonic basin margin[C]//SimoJ A T, Scott R W, Masse J P, et al.Cretaceous carbonate platforms, AAPG Memoir, 1993, 56: 185-199.
21	Buchem F S P V , Razin P , Homewood P W , et al. Stratigraphic organization of carbonate ramps and organic-rich intrashelf basins:Natih Formation (Middle Cretaceous) of Northern Oman[J]. AAPG Bulletin, 2002, 86 (1): 21- 53.
22	田泽普, 刘波, 高计县. 伊拉克鲁迈拉油田白垩系Mishrif组碳酸盐岩生物碎屑和成岩作用特点[J]. 地层学杂志, 2016, 40 (1): 41- 50.
	Tian Zepu , Liu Bo , Gao Jixian . Bioclastic and diagenetic characteristics of Carbonate Rocks of Cretaceous Mishrif Formation in Rumaila Oilfield, Iraq[J]. Journal of Stratigraphy, 2016, 40 (1): 41- 50.
23	Dunham R J . Classification of carbonate rocks according to depositional textures[J]. AAPG Bulletin, 1962, 1, 108- 121.
24	Rankey E C, Berkeley A.Holocene carbonate Tidal Flats[C]//Davis R A, Darymple R W.Principles of Tidal sedimentology, Netherlands: Springer, 2012: 507-536.
25	Murris R J . Middle East:Stratigraphic evolution and oil habitat[J]. AAPG Bulletin, 1980, 64 (5): 597- 618.
26	Grélaud C , Razin P , Homewood P W , et al. Development of incisions on a periodically emergent carbonate platform (Natih Formation, Late Cretaceous, Oman)[J]. Journal of Sedimentary Research, 2006, 76 (4): 647- 669. doi: 10.2110/jsr.2006.058
27	Grélaud C , Razin P , Homewood P . Channelized systems in an inner carbonate platform setting:differentiation between incisions and tidal channels (Natih Formation, Late Cretaceous, Oman)[J]. Geological Society London Special Publications, 2010, 329 (1): 163- 186. doi: 10.1144/SP329.8

研究者	报道年份	研究区	划分方案	方案优势	依据沉积模式
Alsharhan A S	1988，1993	阿拉伯湾南部	沉积坡度非常低,有着近似缓坡的台地边缘，划分为台地边缘斜坡、厚壳蛤礁及礁缘、礁后(包含潟湖和浅礁)	强调了厚壳蛤滩沉积、成岩优势	Wilson(1975) 沉积模式
Aqrawi A A M	1998，2010	伊拉克中、南部	缓坡背景下划分为浅海内陆架、深海外陆架，内陆架分为厚壳蛤礁前斜坡、厚壳蛤礁、浅滩、潟湖、潮下或潮间带	确定了缓坡沉积背景
Mahdi T A	2013，2014	伊拉克南部	根据晴天浪基面与最大风暴面由深向浅划分为深海、浅水开阔海、厚壳蛤生物层、浅滩、后滩、潟湖、潮坪相	应用晴天浪基面、最大风暴面概念，且用浅水开阔海取代斜坡定义，更加凸显缓坡沉积背景与相关特征
王君刘航宇	2016 2019	伊拉克HF油田伊拉克WQ油田	划分为斜坡、台缘边缘、开阔台地、局限台地等，并认为开阔台地或局限台地内的优质储层主要是台内滩沉积	有利于解释静水或局限环境内相变较快的高能沉积体特征
伏美燕	2016	伊拉克HF油田	通过岩相识别划分出厚壳蛤滩、潮下浅滩、深水潮下以及潮汐砂坝等微相	引入潮汐概念对磨圆较好、交错层理等沉积特征进行解释	Flügel(2004) 修正沉积模式
Buchem F S P V	2002	阿曼北部	依据晴天浪基面与风暴浪基面划分为内盆地、外缓坡、中缓坡以及内缓坡亚相	证实了台地内发育下切谷与潮汐相关沉积	Burchette(1992) 沉积模式

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