大港探区奥陶系岩相古地理及储层分布特征研究
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摘要
本文系统地调研了国内外碳酸盐岩储层研究现状及进展；针对大港探区奥陶系碳酸盐岩岩相古地理及储层分布规律，从地层划分与对比、分层系岩相古地理特征与展布、储层成岩作用、储层特征与演化、储层控制因素与分布规律等方面进行了全面系统的研究和论述，并以千米桥潜山为例对奥陶系储层特征及控制因素做了深入分析。主要成果表现在以下几个方面：
1、在综合分析建国以来众多研究学者对研究区奥陶系地层划分结果的基础上，提出了笔者的划分方案，即将奥陶系三分：下奥陶统为冶里组和亮甲山组，中奥陶统分为下马家沟组、上马家沟组和峰峰组，上奥陶统缺失，并对各组的岩电特征进行了详细论述。
2、钻井资料与野外露头考察相结合，明确了工区奥陶系各组段岩性相对稳定，可在全区范围内很好地追踪对比。中奥陶统与上覆石炭系之间为一个大的平行不整合。从南到北，奥陶系地层剥蚀的程度越来越高。
3、奥陶系的岩石类型主要为灰泥石灰岩、泥粉晶白云岩、砂糖状白云岩、垮塌角砾岩，少量颗粒石灰岩及含膏白云岩。不同组岩性差异较大，其中冶里组以灰泥石灰岩和竹叶石灰岩为主，亮甲山组以砂糖状白云岩为主；下马家沟组下段、上马家沟组下段和峰峰组下段以泥粉晶白云岩和膏溶垮塌角砾岩为主；下马家沟组上段、上马家沟组上段和峰峰组上段以灰泥石灰岩为主，其中上马家沟组上段和峰峰组上段化石较丰富。
4、在单井沉积相研究的基础上，对各组的岩相古地理特征进行了详细研究，研究认为：区内发育开阔海、局限海、潮坪、咸化泻湖和滩五种沉积相类型。指出冶里组—亮甲山组以局限海沉积为主，早马家沟早期潮坪发育，晚期为局部台地，晚马家沟早期仍有广泛的潮坪发育，晚期则以开阔海为主，峰峰期早期潮坪广布，晚期则以广泛发育开阔海为主。
5、对碳酸盐岩储层的成岩作用分析认为：
(1)白云岩化作用有四种类型：蒸发泵白云化作用、回流渗透白云化作用、混合水白云化作用、深埋藏白云化作用。大港探区千米桥潜山奥陶系主要产层的白云岩以准同生期的泥晶白云岩为主；
(2)岩溶作用存在地表岩溶、深埋藏岩溶、膏岩岩溶三种类型，并重点对地表岩溶的分
带特征进行了阐述;
(3)充填作用是储层最重要的破坏成岩作用。从大港探区的实例出发，认为充填物类型
除方解石外，泥质充填也较普遍，同时还有硅质、黄铁矿、有机质等多种充填类型，充填
期次至少2一3期;
(4)胶结物地层学研究，将胶结溶蚀成岩作用划分出四个带:渗流带、潜流带、深部混
合带和深部对流带。其中渗流、潜流和深部对流带中部以溶蚀作用为主(潜流带最强烈)，
混合带和对流带上部以胶结作用为主，对流带下部成岩作用不活跃。通过千米桥地区的研
究，认为其胶结物世代存在五期。
6、本区的储层主要是岩溶储层，其储集空间类型主要有晶间孔、晶间溶孔、溶蚀孔洞、
裂缝等。笔者以大港探区千米桥潜山为例，根据岩心描述、物性分析、压汞、铸体、电镜、
薄片及电性特征等综合分析，详细对该区孔、洞、缝特征进行描述，指出该区具有孔、洞、
缝的发育的复合型储层特征。
7、岩溶作用是本区储层形成的重要地质因素，可分为地表岩溶作用和深部岩溶作用，
地表岩溶带后期也常常是深部岩溶作用发生的部位，两者是叠合的。
8、本区岩溶储层的空间分布呈带状，非均质性强，并受水动力带、岩性、沉积相、构
造、风化剥蚀持续时间和古地形的影响。
9、对岩溶储层从古地貌风化淋滤时间、水动力条件、岩性、岩相等方面论述了其主
要控制因素。
①水动力带控制岩溶储层的纵向分布，有利的岩溶储层主要发育在距离不整合面
20一200m的范围内;
②白云岩和石膏发育的地层有利于岩溶储层发育。潮坪环境特别是云坪和膏云坪环境
是最有利的储集岩发育相带;
③裂缝和断层发育的部位是岩溶储层有利的发育部位，裂缝和断层的走向控制岩溶带
的走向;
④风化剥蚀时间越长，越有利于岩溶储层发育;
加
⑤古地形控制地下水流向和流速，也控制了岩溶储层的发育和展布。有利于汇集水流
的地形低洼处和有利于地下水流速加快的高地形坡度处是岩溶储层有利发育部位，岩溶储
层带的走向平行水流方向;
⑥胶结和充填作用是破坏储层的主要作用。根据阴极发光，大港千米桥地区的胶结物
可分出5期，不同期次的胶结物特征不同。利用胶结地层学原理，可以确定裂缝的形成期
次和形成时间;根据充填物包裹体资料分析，大港地区缝洞充填期次至少2一3次。
10、根据储层物性、钻井漏失、放空、油气显示、沉积相等多方面资料，对不同组段
储层进行初步评价，认为峰峰组下部和上马家沟组上段储层较好，其余组段储层较差。
This thesis mainly focuses on Ordivician carbonate strata in northern Dagang Oilfield, including stratagraphic correlation, every formation's lithofaces-paleographical distribution, carbonate diagenesis, reservoir characteristics and its affecting factors, paying close attention to Qianmiqiao buried hill. The main results have been achieved as following: 1 .On the basis of many dividing schemes of Ordivician strata that have been established since the liberation of nation, we determined another scheme of the studying area: Ordivician is divided into three series: Lower, Middle and Upper. Lower Ordivician consists of Yeli and Liangjiashan formations;Upper Ordivician strata is eroded; Middle Ordivician consists of lower Majiagou, upper Majiagou and Fengfeng formations. At the same time, relationship between rock and elctronics for every formation is determined.
2. There are five depositional faces in the area: open sea, restrained sea, tidal flat, salified lagoon and bank. On the basis of depositional studying of single well, concluding lithofaces-paleography of every formation: Yeli-Liangjiashan formations deposit in restrained sea; lower Majiagou formation early in tidal flat and late in restrained platform; upper Majiagou formation early in tidal flat and late in open sea; Fengfeng formation early in tidal flat and late in open sea.
Main diagenesis of carbonate reservoir as following:
(1). There are five types of dolomitization: evaporative pumping, seepage reflux, mixing and deep buried. Ordivician main type of dolomite of Qianmiqiao buried hill in Dagang oilfield is elogenetic micrite and microspar dolomite.
(2). There are three types of karst: subaerial, gypsum dissolution and deep buried karsts., paying more attention to subaerial karst.
(3). Cenmentation is the most important destructive diagenesis of karst reservoir. For Dagang oilfield, cements mainly is calcite, other and fills are mud, silicate, pyrite and organic matter, at least there are two or three stages.
(4). After studying of cement stratagraphy, cementation-dissolution diagenesis is divided into four zones: phreatic, vadose, deep mixing and deep convection zones. Among them, phreatic, vadose and in the middle of convection zones undergone dissolution (especially in vadose zone). The mixing and upper convection zones undergone cementation. The lower convection zone remained unaltered. There are five stages of cements in Qianmiqiao buried hill carbonate strata. 4.There are many reservoir spaces in the studying area. After the studying of core, petrophysics, capillary, impregnated thin section, SEM and electronical characteristics, porosity, cavity and fracture are determined. We conclude the reservoir is of complex pore-cave-fracture type. 5.The karst reservoir is studied by paleography, leaching time, hydrological regime, lithofaces-paleography, combined with outcrops and drilling data, the karst reservoir model is established.
6.Every member and formation are primarily evaluated by petrophysics, drilling accidents and gas show in Dagang oilfield. We conclude that the lower Fengfeng formation and the first member of upper Majiagou formation are of better quality, and the other members are non-reservoir.
1、在综合分析建国以来众多研究学者对研究区奥陶系地层划分结果的基础上，提出了笔者的划分方案，即将奥陶系三分：下奥陶统为冶里组和亮甲山组，中奥陶统分为下马家沟组、上马家沟组和峰峰组，上奥陶统缺失，并对各组的岩电特征进行了详细论述。
2、钻井资料与野外露头考察相结合，明确了工区奥陶系各组段岩性相对稳定，可在全区范围内很好地追踪对比。中奥陶统与上覆石炭系之间为一个大的平行不整合。从南到北，奥陶系地层剥蚀的程度越来越高。
3、奥陶系的岩石类型主要为灰泥石灰岩、泥粉晶白云岩、砂糖状白云岩、垮塌角砾岩，少量颗粒石灰岩及含膏白云岩。不同组岩性差异较大，其中冶里组以灰泥石灰岩和竹叶石灰岩为主，亮甲山组以砂糖状白云岩为主；下马家沟组下段、上马家沟组下段和峰峰组下段以泥粉晶白云岩和膏溶垮塌角砾岩为主；下马家沟组上段、上马家沟组上段和峰峰组上段以灰泥石灰岩为主，其中上马家沟组上段和峰峰组上段化石较丰富。
4、在单井沉积相研究的基础上，对各组的岩相古地理特征进行了详细研究，研究认为：区内发育开阔海、局限海、潮坪、咸化泻湖和滩五种沉积相类型。指出冶里组—亮甲山组以局限海沉积为主，早马家沟早期潮坪发育，晚期为局部台地，晚马家沟早期仍有广泛的潮坪发育，晚期则以开阔海为主，峰峰期早期潮坪广布，晚期则以广泛发育开阔海为主。
5、对碳酸盐岩储层的成岩作用分析认为：
(1)白云岩化作用有四种类型：蒸发泵白云化作用、回流渗透白云化作用、混合水白云化作用、深埋藏白云化作用。大港探区千米桥潜山奥陶系主要产层的白云岩以准同生期的泥晶白云岩为主；
(2)岩溶作用存在地表岩溶、深埋藏岩溶、膏岩岩溶三种类型，并重点对地表岩溶的分
带特征进行了阐述;
(3)充填作用是储层最重要的破坏成岩作用。从大港探区的实例出发，认为充填物类型
除方解石外，泥质充填也较普遍，同时还有硅质、黄铁矿、有机质等多种充填类型，充填
期次至少2一3期;
(4)胶结物地层学研究，将胶结溶蚀成岩作用划分出四个带:渗流带、潜流带、深部混
合带和深部对流带。其中渗流、潜流和深部对流带中部以溶蚀作用为主(潜流带最强烈)，
混合带和对流带上部以胶结作用为主，对流带下部成岩作用不活跃。通过千米桥地区的研
究，认为其胶结物世代存在五期。
6、本区的储层主要是岩溶储层，其储集空间类型主要有晶间孔、晶间溶孔、溶蚀孔洞、
裂缝等。笔者以大港探区千米桥潜山为例，根据岩心描述、物性分析、压汞、铸体、电镜、
薄片及电性特征等综合分析，详细对该区孔、洞、缝特征进行描述，指出该区具有孔、洞、
缝的发育的复合型储层特征。
7、岩溶作用是本区储层形成的重要地质因素，可分为地表岩溶作用和深部岩溶作用，
地表岩溶带后期也常常是深部岩溶作用发生的部位，两者是叠合的。
8、本区岩溶储层的空间分布呈带状，非均质性强，并受水动力带、岩性、沉积相、构
造、风化剥蚀持续时间和古地形的影响。
9、对岩溶储层从古地貌风化淋滤时间、水动力条件、岩性、岩相等方面论述了其主
要控制因素。
①水动力带控制岩溶储层的纵向分布，有利的岩溶储层主要发育在距离不整合面
20一200m的范围内;
②白云岩和石膏发育的地层有利于岩溶储层发育。潮坪环境特别是云坪和膏云坪环境
是最有利的储集岩发育相带;
③裂缝和断层发育的部位是岩溶储层有利的发育部位，裂缝和断层的走向控制岩溶带
的走向;
④风化剥蚀时间越长，越有利于岩溶储层发育;
加
⑤古地形控制地下水流向和流速，也控制了岩溶储层的发育和展布。有利于汇集水流
的地形低洼处和有利于地下水流速加快的高地形坡度处是岩溶储层有利发育部位，岩溶储
层带的走向平行水流方向;
⑥胶结和充填作用是破坏储层的主要作用。根据阴极发光，大港千米桥地区的胶结物
可分出5期，不同期次的胶结物特征不同。利用胶结地层学原理，可以确定裂缝的形成期
次和形成时间;根据充填物包裹体资料分析，大港地区缝洞充填期次至少2一3次。
10、根据储层物性、钻井漏失、放空、油气显示、沉积相等多方面资料，对不同组段
储层进行初步评价，认为峰峰组下部和上马家沟组上段储层较好，其余组段储层较差。
This thesis mainly focuses on Ordivician carbonate strata in northern Dagang Oilfield, including stratagraphic correlation, every formation's lithofaces-paleographical distribution, carbonate diagenesis, reservoir characteristics and its affecting factors, paying close attention to Qianmiqiao buried hill. The main results have been achieved as following: 1 .On the basis of many dividing schemes of Ordivician strata that have been established since the liberation of nation, we determined another scheme of the studying area: Ordivician is divided into three series: Lower, Middle and Upper. Lower Ordivician consists of Yeli and Liangjiashan formations;Upper Ordivician strata is eroded; Middle Ordivician consists of lower Majiagou, upper Majiagou and Fengfeng formations. At the same time, relationship between rock and elctronics for every formation is determined.
2. There are five depositional faces in the area: open sea, restrained sea, tidal flat, salified lagoon and bank. On the basis of depositional studying of single well, concluding lithofaces-paleography of every formation: Yeli-Liangjiashan formations deposit in restrained sea; lower Majiagou formation early in tidal flat and late in restrained platform; upper Majiagou formation early in tidal flat and late in open sea; Fengfeng formation early in tidal flat and late in open sea.
Main diagenesis of carbonate reservoir as following:
(1). There are five types of dolomitization: evaporative pumping, seepage reflux, mixing and deep buried. Ordivician main type of dolomite of Qianmiqiao buried hill in Dagang oilfield is elogenetic micrite and microspar dolomite.
(2). There are three types of karst: subaerial, gypsum dissolution and deep buried karsts., paying more attention to subaerial karst.
(3). Cenmentation is the most important destructive diagenesis of karst reservoir. For Dagang oilfield, cements mainly is calcite, other and fills are mud, silicate, pyrite and organic matter, at least there are two or three stages.
(4). After studying of cement stratagraphy, cementation-dissolution diagenesis is divided into four zones: phreatic, vadose, deep mixing and deep convection zones. Among them, phreatic, vadose and in the middle of convection zones undergone dissolution (especially in vadose zone). The mixing and upper convection zones undergone cementation. The lower convection zone remained unaltered. There are five stages of cements in Qianmiqiao buried hill carbonate strata. 4.There are many reservoir spaces in the studying area. After the studying of core, petrophysics, capillary, impregnated thin section, SEM and electronical characteristics, porosity, cavity and fracture are determined. We conclude the reservoir is of complex pore-cave-fracture type. 5.The karst reservoir is studied by paleography, leaching time, hydrological regime, lithofaces-paleography, combined with outcrops and drilling data, the karst reservoir model is established.
6.Every member and formation are primarily evaluated by petrophysics, drilling accidents and gas show in Dagang oilfield. We conclude that the lower Fengfeng formation and the first member of upper Majiagou formation are of better quality, and the other members are non-reservoir.
引文
1．冯增昭主编，1994，沉积岩石学(第二版)，石油工业出版社。
2．冯增昭等著，1990，华北地台早古生代岩相古地理，地质出版社。
3．大港油田石油地质志编辑委员会(编)，1991，中国石油地质志 卷四 大港油田，石油工业出版社。
4．张吉森等，黄骅坳陷古生界含油气评价及勘探目标选择(内部资料)。
5．张秀莲，1985，碳酸盐岩中氧、碳稳定同位素与古盐度、古水温的关系，沉积学报，第3卷，第4期。
6．陈荣坤，1994，稳定氧碳同位素在碳酸盐岩成岩环境研究中的应用，沉积学报，第12卷，第4期。
7．华北石油会战指挥部，1976，黄骅坳陷港西古潜山带含油性的初步认识(内部资料)。
8．华北石油会战指挥部，1977，黄骅坳陷及周边古潜山含油性的认识及评价(内部资料)。
9．王英华，1992，碳酸盐岩成岩作用与孔隙演化，沉积学报，第10卷，第3期。
10．王英华、张秀莲、杨承运等，华北地台早古生代碳酸盐岩岩石学，地震出版社。
11．苏俊青等，2000，千米桥凝析气田地质特征(内部资料)。
12．滑双君等，2000，大港探区奥陶系碳酸盐岩储层研究(内部资料)。
13. S. Qing Sun, 1995, Dolomite Reservoirs:Porosity Evolution and Reservoir Characteristics;AAPG Bulletin, V. 79, No. 2, P. 186-204.
2．冯增昭等著，1990，华北地台早古生代岩相古地理，地质出版社。
3．大港油田石油地质志编辑委员会(编)，1991，中国石油地质志 卷四 大港油田，石油工业出版社。
4．张吉森等，黄骅坳陷古生界含油气评价及勘探目标选择(内部资料)。
5．张秀莲，1985，碳酸盐岩中氧、碳稳定同位素与古盐度、古水温的关系，沉积学报，第3卷，第4期。
6．陈荣坤，1994，稳定氧碳同位素在碳酸盐岩成岩环境研究中的应用，沉积学报，第12卷，第4期。
7．华北石油会战指挥部，1976，黄骅坳陷港西古潜山带含油性的初步认识(内部资料)。
8．华北石油会战指挥部，1977，黄骅坳陷及周边古潜山含油性的认识及评价(内部资料)。
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