重庆南川三汇场寒武系碳酸盐岩中不同期次大气淡水作用的证据<sup>*</sup>

钱一雄, 何治亮, 李国蓉, 董少峰, 彭守涛, 沃玉进, 张军涛, 焦存礼, 张文涛. (2019)重庆南川三汇场寒武系碳酸盐岩中不同期次大气淡水作用的证据^* [J]. 古地理学报, 21(2): 278-292
Qian Yi-Xiong, He Zhi-Liang, Li Guo-Rong, Dong Shao-Feng, Peng Shou-Tao, Wo Yu-Jin, Zhang Jun-Tao, Jiao Cun-Li, Zhang Wen-Tao. (2019)Evidence of multiepisode dissolution of meteoric fluids of the Middle and Upper Cambrian carbonate rocks of Sanhuichang outcrop,Nanchuan area,Chongqing[J]. Journal Of Palaeogeography, 21(2): 278-292. 复制到剪切板

Doi: 10.7605/gdlxb.2019.02.016
Permissions

重庆南川三汇场寒武系碳酸盐岩中不同期次大气淡水作用的证据^*

钱一雄¹, 何治亮², 李国蓉³, 董少峰¹, 彭守涛², 沃玉进², 张军涛², 焦存礼², 张文涛¹

1 中国石化勘探开发研究院无锡石油地质研究所,江苏无锡 214151

2 中国石化石油勘探开发研究院,北京 100083

3 成都理工大学,四川成都 610059

第一作者简介钱一雄,男,1962年生,博士,教授级高级工程师,研究方向为碳酸盐沉积与储集层。E-mail: qyx9167@vip.sina.com。

收稿日期:2018-11-07

基金资助:*深地项目(编号: 2017YFC0603103),联合基金项目(编号: U1663209)和国家重大科技专项(编号: 2011ZX05005-023)共同资助

摘要

多期构造叠加及多种成岩环境下的早古生代碳酸盐岩储集层形成机理十分复杂。重庆南川三汇场剖面寒武系碳酸盐岩出露完整,是研究沉积与成岩史的理想解剖点之一。研究表明,三汇场剖面寒武系白云岩分别经历了早期海水胶结、大气淡水淋滤、准同生白云岩化、中浅层埋藏、中期构造大气水作用、中晚期埋藏及热液作用和构造晚期表生大气水成岩作用,不同期次的大气淡水作用特征不同。在早成岩期,沿向上变浅的高频层序界面附近发育了鲕模孔、窗格溶孔等组构性溶孔,胶结物和充填物的δ ¹⁸O、δ ¹³C值均比同期海水负偏, ⁸⁷Sr/⁸⁶Sr值与同期海水相近,不发光( CL),含有较小的液相包裹体;加里东晚期—海西期,发育了非组构扩溶孔洞缝,伴有氧化沥青,不发光充填物的δ ¹⁸O、δ ¹³C负偏、 ⁸⁷Sr/⁸⁶Sr值正偏,发育含烃的低温不混溶包裹体,并叠加后期的深埋藏及热液成岩作用;燕山期和喜马拉雅期, 发育孤立的非组构溶蚀孔洞、缝洞,多被巨晶方解石或黏土充填,方解石中δ ¹⁸O、δ ¹³C强烈负偏($\delta^{13}C_{PDB}$=- 4.6‰~- 23.4‰,$\delta^{18}C_{PDB}$=- 8.6‰~- 17.8‰)、含有低温不混溶包裹体(< 28.5℃),是有机质或生物甲烷(细)菌参于下的表生大气水成岩作用产物。

关键词: 碳同位素; 氧同位素; 低温不混溶包裹体; 大气水成岩; 寒武系

中图分类号:P588.345;P595 文献标志码:A 文章编号:1671-1505(2019)02-0278-15

Evidence of multiepisode dissolution of meteoric fluids of the Middle and Upper Cambrian carbonate rocks of Sanhuichang outcrop,Nanchuan area,Chongqing

Qian Yi-Xiong¹, He Zhi-Liang², Li Guo-Rong³, Dong Shao-Feng¹, Peng Shou-Tao², Wo Yu-Jin², Zhang Jun-Tao², Jiao Cun-Li², Zhang Wen-Tao¹

1 Wuxi Institute,Exploration & Production Research Institute,SINOPEC,Jiangsu Wuxi 214151,China

2 Exploration & Development Research Institute,SINOPEC,Beijing 100083,China

3 Chengdu University of Technology,Chengdu 610059,China

About the first author Qian Yi-Xiong,born in 1962,is a professional engineer. He is engaged in researches of carbonate rocks sedimentation and reservoir characterization. E-mail: qyx9167@vip.sina.com.

Fund:Co-funded by the National Key Basic Research Project of China(No.2017YFC0603103),Natural Science Joint Foundation of China(No. U1663209)and National Science and Technology Major Projects of China(No.2011ZX05005-023)

Abstract

How to identify and evaluate the influences of multiepisodes of tectonic activities and diagenesis on Paleozoic carbonate rocks is a fundamental and challenging issue for reservoirs formation mechanism study. It would be valuable to unravel the important information of diagenesis fluid evolution and its relationship with formation of oil and gas pools. The well-preserved outcrop of Cambrian carbonate rocks in SanHuiChang,Nanchuan,Chongqing is an idea natural laboratory to study the depositional and diagenesis history of Paleozoic carbonate. The petrographic and geochemical analyses have demonstrated that the Cambrian carbonate rocks have experienced multiepisodes of diagenesis,including the early penecontemporaneous diagenesis in fresh and marine water,the shallow buried-diagenesis in mixed freshwater and seawater or formation water,karstification in meteoric weathering related to the later Caledonian and Hercynian tectonic activities,the middle and deep buried-diagenesis in formation water or hydrothermal fluid and karstification in meteoric weathering in Yanshan and Himalayan period. In different episodes of diagenesis,the meteoric fresh water has played different roles. In the early stage of meteoric diagenesis,the shallowing-upward high-frequency sequence boundary is characterized by molds,dissolved-pores related to fenestral and fabric-selective pores,less negative excursion of δ¹³C & δ¹⁸O and similar⁸⁷Sr/⁸⁶Sr of cement and matrix when compared to the coeval sea water,non-luminescent cements(CL)and a few small liquor phase inclusions in cements. In the middle stage of diagenesis,the karstification has been developed in subaerial exposure period in Caledonian and Hercynian,which is characterized by non-fabric-selective pores and vugs,a more pervasive non-luminescent of middle and coarse calcites or dull orange dolomites with δ¹⁸O and δ¹³C depletion and positive values of⁸⁷Sr/⁸⁶Sr,oxygenated hydrocarbons(asphalt)and hydrocarbon-bearing,and the low-temperature immiscible inclusions in cements and filling minerals. In addition,this stage of diagenesis has experienced post-meteoric weathering,overprinted and modified by later deep burial diagenesis. In the late stage of diagenesis,the last karstification happened in meteoric weathering environment in Yanshan and Himalayan period,which is documented by isolate-distribution of pores and vugs and fractures with mostly filled by calcites and clay,precipitation of the coarse and giant calcites crystal with δ¹⁸O and δ¹³C strongly negative excursion($\delta^{13}C_{PDB}$=-4.6‰~-23.4‰,$\delta^{18}C_{PDB}$=-8.6‰~-17.8‰),and the low-temperature immiscible inclusions(homogenization temperature <28.5℃),indicating a diagenesis triggered by meteoric fluid interacted with soil-related(carbon)organic acids or biological methane bacteria activities.

Key words: carbon isotope; oxygen isotope; low temperature immiscible inclusions; fresh water diagenesis; Cambrian

文章图片

多期构造运动的叠加, 对碳酸盐岩储集层或油气藏产生强烈改造, 造成储集层形成与保存及成岩流体演化十分复杂, 导致判识其成岩环境和成岩期次较为困难。而碳酸盐岩表生大气水岩溶作用的环境分析及期次判识, 却对明确储集层形成及其与油气充注和保存的关系具有重要意义(Loucks, 1999; Purdy and Waltham, 1999; Moore, 2001; 陈学时等, 2004; 钱一雄等, 2005, 2009)。

文中在对重庆南川三汇场寒武系剖面详细观察的基础上, 对碳酸盐岩主要岩相及缝洞充填物进行了系统采样, 采用白云岩有序度、阴极发光、微区碳氧同位素、锶同位素、包裹体成因及均一测温和盐度分析等多种手段, 分析探讨中上寒武统碳酸盐岩的主要成岩演化阶段, 揭示加里东期、燕山期— 喜马拉雅期等多期表生岩溶的地质— 地球化学特征。

1 区域地质背景

三汇场剖面位于川中隆起带, 与川东南拗褶带相邻(图 1), 后者由NE向以及NNE向中生代高陡的背斜带— 断裂带和宽缓的向斜带构成隔挡式褶皱组成。自震旦纪至中二叠世, 该地区均为稳定的海相碳酸盐岩台地, 先后经历了被动大陆边缘(Z-O)、周缘前缘盆地(P-T₂)和后造山前陆盆地的演化(马力等, 2004; 陈宗清, 2013), 且郁南、都匀、广西、云南、东吴、印支、燕山和喜马拉雅等多期构造运动先后叠加(马力等, 2004; 陈宗清, 2013), 尤其是广西、印支、燕山等运动, 对该地区碳酸盐岩储集层或油气藏进行了强烈改造。

	Figure Option View Download New Window
	图 1 重庆南川三汇场寒武系剖面位置Fig.1 Location of Sanhuichang outcrop of the Cambrian in Nanchuan area, Chongqing

川东南的寒武系自下而上可分为:下寒武统麦地坪组、牛蹄塘组或九老洞组、筇竹寺组、明心寺组、金顶山组、清虚洞组(∈ ₁q, 相当于龙王庙组), 中寒武统陡坡寺组(或高台组∈ ₂g)、石冷水组(∈ ₂s)和平井组(∈ ₂p), 上寒武统后坝组(∈ ₃h)和毛田组(∈ ₃m)(或称之为娄山关群), 上覆下奥陶统桐梓组(O₁t)(王剑, 1990; 李天生, 1992; 张帆等, 1999; 王素芬等, 2008; 李皎和何登发, 2014)。其中, 下寒武统清虚洞组(∈ ₁q)为潟湖— 潮坪沉积(王剑, 1990; 李天生, 1992), 中寒武统高台组(∈ ₂g)、石冷水组(∈ ₂s)及平井组(∈ ₂p)主要为潮坪、台内滩及潟湖沉积, 上寒武统后坝组(∈ ₃h)和毛田组(∈ ₃m)主要为潮坪、(藻)丘滩沉积(图 2)。

	Figure Option View Download New Window
	图 2 重庆南川三汇场剖面寒武系碳酸盐岩沉积层序与采样位置Fig.2 Depositional succession and sampling locations in the Cambrian carbonate rocks at Sanhuichang outcrop, Nanchuan area, Chongqing

高石梯— 磨溪下寒武统龙王庙组大气田的碳酸盐岩储集层研究表明, 颗粒滩相的孔隙型储集体发育粒内溶孔、粒间溶孔、晶间孔及溶孔、膏溶孔、裂缝等储渗空间(王素芬等, 2008; 黄文明等, 2009, 2011; 金民东等, 2014; 李亚林等, 2014; 周进高等, 2015), 它们的形成主要与滩相沉积作用、兴凯运动时期(寒武纪未)或局部叠加了加里东期的大气淡水岩溶作用、埋藏期白云化作用及TSR溶蚀作用等有关(黄文明等, 2009, 2011; 金民东等, 2014; 李亚林等, 2014; 周进高等, 2015)。

2 采样与测试

沿三汇场剖面底部的清虚洞组(∈ ₁q)至顶部下奥陶统桐梓组(O₁t)开展了较系统的样品采集工作。每组中的主要代表性岩性(相)段至少采集1件样品, 特殊的缝洞发育或充填带适当增加采样点, 共计采集样品66件(图 2)。分析测试项目包括铸体、薄片共66件、阴极发光5件、全岩及其缝洞充填物的碳氧同位素13件、白云石有序度和锶同位素各7件、流体包裹体10件。

铸体薄片磨制由合肥工业大学资源与环境工程学院完成。阴极发光测试在中国石化石油勘探开发研究院构造与沉积储层实验室完成, 所用仪器为BLM-3RX型阴极发光仪, 共测试样品5个。

白云石有序度分析由成都理工大学油气藏地质及开发工程国家重点实验室完成, 使用的仪器为D/max-2500型X射线衍射仪。

碳氧稳定同位素测试由国家地质实验测试中心完成, 测试中采用McCrea(1950)100%正磷酸法处理样品, 即: 首先将样品置于恒温箱中烘干, 然后在真空中与100%的正磷酸反应, 平衡温度50℃, 平衡时间24 h。测试仪器为Finngan-MAT252气体质谱仪, 分析精度± 0.2‰ 。

锶同位素测试是由核工业地质研究院测试中心完成, 采用仪器为IsoProbe T热电离质谱仪, 测量精度优于3μ g/g。

流体包裹体测试由中国石化石油勘探开发研究院无锡石油地质研究所测试中心完成。测试过程中, 利用与 Leica 显微镜接口的Linkam THMSG 2600型冷热台先校正温度, 升温速率为5℃/min; 当包裹体中气泡变小接近均一时, 升温速率降至 1℃/min。均一温度测试精度为± 1℃。密度系采用PVTX(英国Linkam公司)软件按均一温度和盐度(未测出冰点(盐度)的按纯水体系)计算得出的。

3 岩相学特征

3.1 岩石类型

三汇场剖面中上寒武统岩石类型较多。灰岩的主要类型有泥晶灰岩(图 3-a, 3-b)、亮晶砂砾屑灰岩、含生屑或含藻的泥晶灰岩、亮晶至微晶的藻鲕粒灰岩(图 3-c; 图 4-b, 4-c)、藻球粒灰岩(肾形藻)(图 3-d)。白云岩类型较多, 包括残留藻结构白云岩、藻粘结白云岩、叠层石凝块白云岩(微生物白云岩)(图 3-e, 3-i)、泥晶白云岩、泥粉晶白云岩、泥微晶白云岩、含硅质团块泥粉晶白云岩、粉细晶白云岩(图 3-g)、含残余砂(砾)屑鲕粒(幻影)粉细晶白云岩、含砂质粉细晶白云岩、角砾状粉细晶白云岩、不等晶白云岩等(图 3-h)。另有灰岩— 白云岩及膏岩之间的过渡性岩类, 如含云质灰岩、含陆屑云灰岩及含膏质、含泥质的泥粉晶白云岩等(图 3-f)。

Figure Option
View Download New Window

图 3 重庆南川三汇场寒武系碳酸盐岩胶结物与缝洞中充填物特征
a— SHS-007, ∈ ₂s, 含云泥晶灰岩, 沿裂隙— 孔道(Ch-VC_Ⅱ)发生第2期和第3期方解石沉淀及烃类充注, 其中第2期为沿洞壁向中心生长的短柱— 粒状方解石(C_Ⅱ), 后有褐黄色烃类或沥青(OA_Ⅰ)(又遭后期水洗氧化、细菌作用)沿剩余孔隙中心充注, 第3期为不规则裂隙— 溶洞中充填的粗巨晶他形方解石(VC_Ⅲ); b— SHS-009, ∈ ₂s, 泥晶灰岩, 发育3组裂隙, 分别是第1组微裂隙(F_Ⅰ)、第3组裂隙(FC_Ⅲ)以及第4组开启裂隙(F_Ⅳ); c— SHS-013, ∈ ₂p, 泥微晶球粒— 鲕粒灰岩, 发育等厚微晶方解石(MC)、纤状— 针状— 纤柱状的海底渗流、潜流带胶结(AC或RFC), 鲕模孔(OM)以及粒间溶蚀孔(IP)分别被泥晶方解石(C₀)、粒状方解石(C_Ⅰ)以及褐黄色烃类或沥青(OA_Ⅰ)所充填, 有1组裂隙(F_Ⅲ)切穿鲕模孔(OM)以及粒间溶蚀孔(IP), 被细粒状方解石(FC_Ⅱ)及沥青(OA_Ⅰ)充填; d— SHS-017, ∈ ₃h, 弱云化的藻球粒灰岩, 局部发育肾形藻集合体, 占15%~20%, 发育铸模孔(OM)、大量溶孔洞(V_Ⅰ), 充填了较干净的细粒方解石C_Ⅰ; e— SHS-023, ∈ ₃h, 残余藻球粒— 团粒(块)泥粉晶云岩, 沿团粒边缘至孔隙中发育等厚纤状文石— 方解石(C₀:MC-AC)、粒状方解石— 白云石(D_Ⅰ: PC_Ⅰ-PD_Ⅰ), 再发育了晶间孔或溶孔(BC-BP)、粒间的溶孔洞(IP-V), 分别由较干净中晶方解石(C_Ⅱ)及沥青(OA_Ⅱ)充填, 被第3期裂隙(F_Ⅲ)所切割; f— SHS-028, ∈ ₃h, 含膏质泥粉晶云岩(D_0:10~60 μ m), 局部为重结晶的“ 雾心亮边” 粉细晶白云岩(D_Ⅰ), 半自形— 他形, 曲面粒状镶嵌, 溶蚀孔洞中分别由中晶白云石(D_Ⅱ)、中粗晶的方解石(C_Ⅳ)以及硬石膏(Anh)充填, 正交光; g— SHS-035, ∈ ₃h, 残余藻球粒粉细晶云岩, 2组开启微裂隙, 宽度小于0.01 mm, 单偏光; h— SHS-047, ∈ ₃m, 残余藻球粒或团粒不等晶云岩, D₀为较脏粉晶白云石, D_Ⅰ为类似于“ 雾心亮边” 的中细晶白云石, 沿边缘发生退云化, 半自形曲面— 直面镶嵌, D₀中残余的晶间孔(BC)及晶间溶孔(BP)以及裂隙中(F_Ⅲ)充填了1期沥青(OA_Ⅱ), 单偏光; i— SHS-061, ∈ ₃m, 浅灰色藻泥粉晶云岩, 沿裂隙— 溶沟— 孔洞中(F_Ⅳ-Ch-V_Ⅳ)的巨晶方解石(C_Ⅳ)充填, 晚期有1组开启裂隙穿过(F_Ⅳ)Fig.3 Characteristic of fillings and cements of pores or vugs and fractures of the Cambrian carbonate rocks from Sanhuichang outcrop, Nanchuan area, Chongqing

Figure Option
View Download New Window

图 4 重庆南川三汇场剖面寒武系碳酸盐岩的阴极发光特征(CL)及微区

δ^{13} C_{PDB}

和

δ^{18} O_{PDB}

值
a— SHS-047, ∈ ₃m, 残余藻球粒不等晶云岩, 残余藻球粒一般不发光、部分发暗橙红色光(D₀), 晶间孔、晶间溶孔中白云石分别发暗橙红色光(PD_Ⅰ)、不发光(PD_Ⅱ); b, c— SHS-015, ∈ ₂p, 残余生屑亮晶鲕粒灰岩, 砂屑及藻鲕粒大小为50~300^μm, 鲕粒发中等桔红色光(C₀), 沿颗粒边缘的等厚纤状胶结方解石(AC)和往中心的粒状方解石(PC_Ⅰ)均发暗桔红色光, 少量鲕模孔中的沥青(OA_Ⅰ)不发光, 少量黏土(Clay)发蓝色光, 有2期孔缝洞方解石充填物, 其中1期(FC_Ⅱ)发中等亮边橙红色光、2期的再溶蚀(FC_Ⅲ)不发光; d— SHS-061, ∈ ₃m, 残余藻球粒的泥粉晶— 粉细晶白云岩, 前者发均匀中等橙红色光, 后者(D₁:50~150μ m)晶体内部发暗橙红色光、边缘环带呈亮橙红色光(雾心亮边), 孔洞中的中粗晶环带白云石(VD_Ⅱ)发中等或亮的橙红色光, 溶洞中的巨粗晶方解石(VC_Ⅳ)不发光, 成岩序列依次为D₀重结晶、埋藏云化D_Ⅰ、埋藏充填D_Ⅱ、大气水作用充填VC_Ⅳ, ①, ②, ③为微区位置Fig.4 Cathodluminescence characteristics and

δ^{13} C_{PDB}

δ^{18} O_{PDB}

value of micro-drill samplings of the Cambrian carbonate rocks from Sanhuichang outcrop, Nanchuan area, Chongqing

由于白云岩为研究区的主要岩类, 且各种残余藻结构较为发育, 因此笔者依据Sibley和Gregg(1987)、并参考王丹(2010)的白云石分类方案, 按残余藻结构、晶体大小、晶形及晶面接触关系等多因素, 对三汇场剖面的白云岩进行了分类。主要类型如下:

1)残余藻屑泥晶白云岩(SHS-034)。粒径2~5μ m, 他形晶— 半自形晶, 粒状镶嵌结构, 阴极发光下为暗红色— 粉红色。

2)残余藻纹层— 藻球粒泥粉晶白云岩(SHS-025)。粒径10~25 μ m, 半自形晶, 粒状直面— 曲面镶嵌结构。其中, 藻球粒呈条带状, 大小一般为20~50μ m, 占10%~15%, 部分发生了重结晶作用。

3)残余藻球粒微晶白云岩。基本特征同残余藻纹层— 藻球粒泥粉晶白云岩, 但藻球粒所占的比例较高, 为20%~40%, 局部可见肾形藻(图 3-d)。

4)残余藻球粒— 团粒泥粉晶白云岩。藻球粒及藻团粒粒径为100~500μ m, 占20%~40%(图 3-e)。

5)残余藻球粒— 团粒粉细晶云岩。基本特征同残余藻球粒— 团粒泥粉晶白云岩, 藻团粒占5%~15%。基质粒径为60~100μ m, 半自形, 粒状曲面— 直面镶嵌结构, 有序度为0.52~0.60(SHS-027, SHS-038)。

6)残余藻球粒粉细晶及细晶白云岩。晶体粒径为50~200μ m, 以他形— 半自形为主, 次之为自形— 半自形, 可见环带或雾心亮边, 曲面镶嵌结构(图 3-g; 图 4-d)。雾心亮边白云石发中等橙红色光、局部亮橙红色光。有序度为0.84~0.86(SHS-042, SHS-060)。

7)残余藻球粒不等晶白云岩。晶体粒径以100~150μ m为主, 其次为200~250μ m, 偶见300~400μ m, 半自形, 直面— 曲面镶嵌结构(图 3-h; 图 4-a)。

8)含灰残余鲕粒白云岩。鲕粒大小为200~250μ m, 占15%~20%。

3.2 成岩期次

三汇场剖面中上寒武统碳酸盐岩的成岩阶段及主要事件大致可划分为5个阶段。

1)早期成岩阶段。包括海底成岩胶结、准同生期白云石化以及早期裂隙、大气淡水溶蚀及充填作用。主要特征是围绕藻球粒— 团粒、鲕粒、生屑或砂砾屑等颗粒边缘形成了等厚环边、纤维、纤柱状方解石(图 3-c, 3-e)和粒状方解石(图 4-b, 4-c), 在残余藻结构、生物(屑)中发育体腔孔(图 3-d)、鲕模孔(图 3-c, 3-d)、窗格孔、膏模孔等组构性溶蚀, 且往往发育于高频层序的上部。

2)中浅层埋藏成岩阶段。包括压实与压溶作用、重结晶作用、埋藏白云岩化等。如粉晶自形白云石(图 3-e), 往往发暗桔红色光, 发育晶间孔、晶间溶孔(图 3-f; 图 4-d中的D_Ⅰ和D_Ⅱ)。另外, 沿晶间孔、铸模孔和溶蚀孔洞、缝发生了第1期烃类充注, 后受细菌改造或水洗氧化形成沥青(图 3-f)。

3)中期大气水成岩阶段。表现为沿早期裂隙方解石的再溶蚀及非组构的扩溶裂隙, 同时发生了烃类的水洗氧化, 先期孔洞及裂缝中的方解石充填局部发育去膏化、去云化作用, 如沿“ 微裂隙” 带状边缘的亮边退云化(图 3-h)。

4)中晚期的中深埋藏成岩阶段。受持续埋藏过程、晚二叠世岩浆及其热液作用的影响, 晶间孔、晶间溶孔(图 3-f; 图 4-d)经历了强烈压实、重结晶作用后大多消失, 白云石晶体增大, 有序度增加, 如中晶白云石(SHS-053, SHS-030, 200~300 μ m, δ =0.80)的形成。早期烃类裂解为碳质沥青, 沿裂隙及残留孔隙发生了第2期烃类充注(OA_Ⅱ)(图 3-a), 被发橙红色光的环带白云石(图 4-d)和石英等矿物充填。

5)晚期大气水成岩阶段。受燕山期— 喜马拉雅期的区域构造褶皱、构造抬升影响, 沿构造背斜轴部或翼部的裂隙发生了大气水溶蚀作用, 孤立孔洞中大多充填了较为纯净的粗至巨晶方解石(SHS-022)(图 3-b, 3-c, 3-d, 3-i), 阴极下一般不发光(图 4-d); 后又叠加了更晚期的开启微裂隙。

3.3 构造裂隙及其充填物特征

野外及室内观察结果表明, 研究区内共发育4组裂隙。第1组裂隙(F_Ⅰ)的宽度较小(< 0.01mm), 多被细粒方解石(FC_Ⅰ)、沥青(OA_Ⅰ)、有机质及氧化铁、泥质充填, 如SHS-013、SHS-017(图 3-c)。第2组裂隙相对较宽, 弯曲、扩溶现象明显(0.2~0.3mm), 有中晶方解石(FC_Ⅱ, 图 3-a)、中细晶白云石(D_Ⅱ, 图 4-d)半充填或全充填, 分别发中强橙红色— 橙黄红色光, 伴有黑色或棕黄红的2期烃类(沥青)充填(图 3-a), 推测为多期活动的产物。第3组裂隙最宽, 可达1mm, 由十分干净的中粗晶或粗晶方解石(FC_Ⅳ; 大小为0.2~0.5 mm)充填(图3-c), 不发光(C_Ⅳ)(图 4-d), 推测为中晚期构造活动的产物。第4组是网状裂隙或微裂隙, 宽度小于0.01^mm, 无充填, 切穿上述第3组裂隙(图 3-g, 3-i), 代表最晚期的构造裂隙。

4 地球化学证据

4.1 同位素

寒武系基质白云石的碳、氧和锶同位素测试值参见表 1。其中, 上寒武统4件基质白云石的 $δ^{18} O_{PDB}$ 平均为-6.90‰ (-7.5‰ ~-5.6‰ ), $δ^{13} C_{PDB}$ 平均为0.10‰ (-0.9‰ ~1.3‰ ), ⁸⁷Sr/⁸⁶Sr值平均为0.7093(0.7092~0.7094)。寒武系由下而上, 基岩中白云石的 $δ^{13} C_{PDB}$ 发生从正值、负值至正、负值变化, $δ^{18} O_{PDB}$ 均为负偏, 且 δ ¹⁸O 和δ ¹³C呈线性相关的协调变化, 推测其遭受到淡水潜流或大气淡水的改造影响。

表 1 重庆南川三汇场剖面寒武系白云岩及缝洞充填物的有序度和碳、氧、锶同位素值 Table1 Data of sequentiality(degree of order),

δ^{13} C_{PDB}

δ^{18} O_{PDB}

, ⁸⁷Sr/⁸⁶Sr for dolostone and fillings or cements of the Cambrian carbonate rocks from Sanhuichang outcrop, Nanchuan area, Chongqing

样号	测试样品	地质时代	结构及产状	Ⅰ (015) /Ⅰ (110)	$δ^{13} C_{PDB}$ /‰	$δ^{18} O_{PDB}$ /‰	⁸⁷Sr/⁸⁶Sr	⁸⁷Sr/⁸⁶Sr 误差
SHS-002	粉晶白云岩	∈ ₁q	粉晶D₀		0.2	-6.3	0.709 866	0.000 009
SHS-003	粉晶白云岩	∈ ₂s	粉晶D₀		-1.0	-6.2	0.710 752	0.000 010
SHS-011	粉晶白云岩	∈ ₂p	粉晶D₀		-0.4	-7.6	0.709 304	0.000 009
SHS-027	粉细晶白云岩	∈ ₃h	粉细晶D_Ⅰ-D_Ⅱ	0.60	-0.9	-7.3	0.709 263	0.000 008
SHS-038	粉细晶白云岩	∈ ₃h	细晶D_Ⅱ	0.52	1.3	-7.2	0.709 389	0.000 016
SHS-042	细晶白云岩	∈ ₃h	细晶D_Ⅱ	0.86	0.7	-7.5	0.709 278	0.000 008
SHS-060	中细晶白云岩	∈ ₃m	细晶D_Ⅱ	0.84
SHS-061-①	中细晶白云岩	∈ ₃m	细晶D_Ⅱ		-0.8	-5.6
SHS-007	粒状方解石	∈ ₂s	FC_Ⅱ		-2.1	-8.6	0.709 606	0.000 011
SHS-010	细晶白云石	∈ ₂p	FD_Ⅱ		-3.3	-15.9
SHS-015	中细晶白云石	∈ ₂p	VD_Ⅱ	0.68	-3.4	-9.8	0.709 249	0.000 011
SHS-021	粗晶方解石	∈ ₃h	VC_Ⅳ		-4.6	-17.8
SHS-053	中晶白云石	∈ ₃m	VD_Ⅲ	0.80	-2.8	-18.2
SHS-061	中细晶白云石	∈ ₃m	VD_{Ⅰ -Ⅱ}	0.64	-0.6	-11.7	0.709 295	0.000 010
SHS-061-③	中粗晶白云岩	∈ ₃m	D_Ⅲ		-1.4	-8.5
SHS-061-②	粗晶方解石	∈ ₃m	VC_Ⅳ		-23.4	-11.2

注: ①、②和③为微区样品。

表 1 重庆南川三汇场剖面寒武系白云岩及缝洞充填物的有序度和碳、氧、锶同位素值 Table1 Data of sequentiality(degree of order),

δ^{13} C_{PDB}

δ^{18} O_{PDB}

, ⁸⁷Sr/⁸⁶Sr for dolostone and fillings or cements of the Cambrian carbonate rocks from Sanhuichang outcrop, Nanchuan area, Chongqing

中寒武统孔洞中的中细晶白云石(VD_Ⅱ)的 $δ^{18} O_{PDB}$ 为-9.8‰ , $δ^{13} C_{PDB}$ 为-3.4‰ , ⁸⁷Sr/⁸⁶Sr值为0.7092。上寒武统孔洞中的中细晶白云石(VD_Ⅱ)的 $δ^{18} O_{PDB}$ 为-11.7‰ , $δ^{13} C_{PDB}$ 约为-0.6‰ , ⁸⁷Sr/⁸⁶Sr值为0.7093‰ ; 中粗晶白云石(VD_Ⅲ)的 $δ^{18} O_{PDB}$ 、 $δ^{13} C_{PDB}$ 分别为-18.2‰ 和-2.8‰ ; 粗晶方解石(VC_Ⅳ)的 $δ^{18} O_{PDB}$ 为-17.8‰ ~-11.2‰ , $δ^{13} C_{PDB}$ 为-23.4‰ ~-4.6‰ 。中寒武统裂隙中的中粗晶白云石(FD_Ⅱ)的 $δ^{18} O_{PDB}$ 为-15.9‰ , $δ^{13} C_{PDB}$ 为-3.4‰ ; 粒状方解石(FC_Ⅱ)的 $δ^{18} O_{PDB}$ 为-8.6‰ , $δ^{13} C_{PDB}$ 为-2.1‰ , ⁸⁷Sr/⁸⁶Sr值为 0.7096。

不难看出, 与基岩相比, 裂隙及孔洞中充填的白云石、方解石的 $δ^{18} O_{PDB}$ 、 $δ^{13} C_{PDB}$ 明显负偏, 表现为从中细晶至中粗晶的白云石 $δ^{18} O_{PDB}$ 的负偏移程度明显增加, 反映了结晶温度的升高趋势, 这与下述的流体包裹体均一测温值较为吻合。而孔洞中的粗晶方解石(VC_Ⅳ)具有特别低的 $δ^{13} C_{PDB}$ 值, 应是细菌快速氧化有机碳形成的CO₂产物, 反映了潮湿环境下土壤有机质参与的大气水岩溶作用(Anderson and Arthur, 1983)。

孔洞中的中细晶白云石(VD_Ⅱ)与裂隙— 孔洞中的粒状方解石的⁸⁷Sr/⁸⁶Sr值(分别为0.70925和0.70960)接近, 或稍高于寒武系海水的⁸⁷Sr/⁸⁶Sr值(0.7080~0.7093, Ingram and Sloan, 1992; Denison et al., 1994; Veizer et al., 1999; 黄思静等, 2002), 反映其主要受海源流体的影响。另据黄文明等(2009)的分析结果, 合12井、安平1井和丁山1井寒武系中的孔洞白云石的⁸⁷Sr/⁸⁶Sr值分别为0.7095~0.7117、0.7095~0.7099和0.7092, 安平1和丁山1井孔洞中方解石的⁸⁷Sr/⁸⁶Sr值分别为0.7103、0.7131~0.7160, 呈明显正偏, 反映其形成于有明显的陆源碎屑参与的大气水成岩环境, 这与依据 $δ^{18} O_{PDB}$ 、 $δ^{13} C_{PDB}$ 值推测的结论一致。

总体来看, 寒武系以粉细晶白云岩为主, 次之为中细晶或中粗晶白云岩, $δ^{18} O_{PDB}$ 及 $δ^{13} C_{PDB}$ 比当时海水稍负偏, 反映了白云岩化温度的影响, 对应于图 5中的Ⅰ 。这种与大气淡水有关的环境可进一步划分为: (1) $δ^{18} O_{PDB}$ =-11.7‰ , $δ^{13} C_{PDB}$ =-0.7‰ , 可能代表了早期大气淡水作用(Ⅱ ); $(2) δ^{18} O_{PDB}$ =-9.8‰ ~-8.6‰ , $δ^{13} C_{PDB}$ =-3.4‰ ~-2.1‰ , 可能为中构造期大气水作用(Ⅲ ); $(3) {δ^{1}}^{8}$ O_PDB=-17.8‰ ~-11.2‰ , $δ^{13} C_{PDB}$ =-23.4‰ ~-4.6‰ , 指示了晚构造期的大气水作用(Ⅳ )。

	Figure Option View Download New Window
	图 5 重庆南川三汇场剖面寒武系白云岩及缝洞充填物的碳氧同位素值Fig.5 $\delta^{13}C_{PDB}$ and $\delta^{18}C_{PDB}$

4.2 流体包裹体

本次研究共采集三汇场寒武系中缝洞方解石及白云石10件样品, 详细观察与显微测温发现, 白云石中的流体包裹体较少且很小(< 3μ m), 较难得到可靠数据。因此, 补测邻区的林1井(Lin1, 寒武系埋深为4500m左右)、沙湾范店寒武系剖面作为补充及验证(表 1), 采用了二次升、降温得出均一测度值。

下寒武统清虚洞组(SHS-001)及上寒武统毛坝组孔洞中(SHS-061)粗晶方解石(VC_Ⅳ)中流体包裹体的特征为:大小为2~7μ m, 最大者为13.2μ m左右; 以椭圆— 圆形为主, 次之为柱状至不规则状; 以液相为主, 少量为气液盐水两相(表 2; 图 5; 图 6)。

表 2 南川三汇场上寒武统毛田组白云岩缝洞充填物方解石流体包裹体特征及均一测温数据(SHS-061)。 Table2 Characteristic and data of Homogenization temperature for two-phase aqueous inclusions WLmm, WKV of calcite in vugs of Maotian Formation, Upper Cambrian carbonate rocks of Sanhuichang, Nanchuan

Figure Option
View Download New Window

图 6 南川三汇场下寒武统清虚洞组(SHS-001)和上寒武统毛田组孔洞中(SHS-061)方解石中包裹体显微特征与均一测温值
a— SHS-001溶孔洞中的粒状方解石, 见沿解理孤立分布的气液两相盐水包裹体(L+G); b— 同a, 气液比低的、较大的、呈带状分布的两相盐水包裹体; c— SHS-061溶洞中的粗晶方解石, 见孤立分布的气液两相盐水包裹体; d— 同c, 沿解理呈带状分布的液相及气液两相盐水包裹体Fig.6 Occurrences and homogenization temperature of fluid inclusions of calcite in vugs of the Qingxudong Formation of Lower Cambrian(SHS-001) and Maotian Formation of Upper Cambrian(SHS-061) carbonate rocks in Sanhuichang, Nanchuana

均一测温表明, SHS-001样品中包裹体的特征为: (1)气液两相中的气液比低, 一般为3%, 无色、无荧光; (2)均一温度值变化较大(63~103.0℃, 图 6-a, 6-b), 冰点达27.9℃(亚稳态, 可能为过热冰); (3)存在3个温度峰值区间, 分别为63~69.2℃, 77.5~82.5℃和90.9~103.0℃。

SHS-061样品中包裹体的特征为: (1)形态多, 气液比较低, 一般为3%~5%, 少数达10%, 无色、无荧光; (2)均一温度的最低值为28.5℃(28.5℃~57℃, 图 6-c, 6-d), 密度为0.9850~0.9951g/cm³; (3)同样存在3个均一温度变化区间, 分别为28.5~34.5℃, 34.5~45℃和50~57℃。

早在1994年, Goldstein和Reynolds指出了大气淡水成岩环境下形成的流体包裹体常为不混溶流体包裹体, 并具有特殊的岩相学特征: (1)渗流带大气淡水中的流体包裹体的气液比变化大; (2)均一温度非常离散; (3)流体组分主要为低盐度、相对较纯的H₂O-CO₂(少量CH₄、NaCl及无机盐等)。它的成因特点为: (1)包裹体的成因类型相同, 即它们是同期捕获的, 温度与压力相同; (2)具有2种或2种以上的相态, 即在不同体积比例、组成的多相介质中形成; (3)由于各个包裹体的相充填度、流体成分不同, 其均一温度不能反映捕获时的温度, 但可根据富含端元组分包裹体中相同(近似)的均一温度来代表捕获时流体温度。

SHS-061孔洞的中粗晶方解石(VC_Ⅳ)中, 流体密度为0.985~0.995g/cm³, 十分接近理想纯水的1.0g/cm³, 气液比较低且有较大变化, 无荧光, 成因产状或类型相同或相似, 均一温度值变化较大, 据此推断所测样品的均一温度值不能代表包裹体捕获时的均相(单相)体系中捕获的流体温度值, 其应等于或低于28.5℃。与前类似, SHS-001孔洞方解石中的流体包裹体为相同环境下的产物, 虽实测的均一温度相差达40℃(图7), 但仍是大气水环境下不混溶捕获。

	Figure Option View Download New Window
	图 7 南川三汇场上寒武统毛田组缝洞充填物方解石中的流体包裹体均一测温频率图 Lin1-053样品采自林1井, FDY-044样品采自乐山范店剖面Fig.7 Homogenization temperature for two-phase aqueous inclusions WL+V of calcite in vugs of the Maotian Formation of Upper Cambrian carbonate rocks in Sanhuichang, Nanchuan

林1井及乐山范店寒武系— 上震旦统灯影组孔洞中的粗晶白云岩中的流体包裹体分析表明, 至少有2期或3期的烃类充注, 分别对应于中等埋藏(82~95.5℃)、深埋(115~140℃)及热液活动期(192.5~220℃), 这对应于成岩序列中第②和④过程。

5 大气淡水特征及成因

5.1 多期大气淡水作用特征

综上所述, 成岩早期、中期及晚构造成岩期的大气淡水作用特征既有相似性, 也有不同的特征。笔者从不同成岩阶段、产状及成因、胶结物或充填物类型、阴极发光、同位素及流体包裹体等方面, 对南川三汇场寒武系碳酸盐岩中的大气水成岩特征进行简单的总结(表 3)。

表 3 南川三汇场寒武系碳酸盐岩中不同成岩阶段中大气淡水作用主要特征和判识标志一览表 Table3 Characteristic and identification for fresh water diagenesis in different stages of the Cambrian carbonate rocks of Sanhuichang, Nanchuan

5.2 构造对大气淡水作用的影响

众所周知, 不整合面、褶皱、断裂、构造抬升与剥蚀、海平面升降、沉积岩相及旋回、古气候、古地形、古地貌等诸多因素, 均会对大气淡水岩溶作用产生重要影响。

研究区在中寒武世、晚寒武世末期、志留纪末期、早二叠世、晚二叠世早期分别发育了多期构造运动, 其中加里东期— 海西期的构造抬升与剥蚀, 导致研究区内缺失了部分志留系、泥盆系至石炭系。晚白垩世的燕山期构造运动, 形成了“ 隔挡— 隔槽式” 构造, 抬升剥蚀幅度超过4200m(刘树根等, 2008)。喜马拉雅运动则进一步使其暴露于地表(图 8)。上述挤压褶皱、构造隆升均为大气水的岩溶作用提供了条件, 断裂作用及岩石破裂为富含CO₂的大气淡水、地层流体等渗流、溶蚀与交代白云石以及方解石的沉淀提供了通道及场所。白云岩的大气淡水溶蚀不同于灰岩, 前者不易形成渗、潜流分带明显的岩溶带, 大气淡水沿白云岩中的晶间孔、微裂隙等发生弥漫的去云化(方解石交代), 逐渐形成孤立分布的溶孔(洞), 并由裂隙沟通孔洞。

	Figure Option View Download New Window
	图 8 南川三汇场寒武系碳酸盐岩成岩阶段与构造埋藏史演化示意图资料来源: H-48-(30)1︰20万重庆南川幅, 按地层残留厚度, 未根据水深及压实等进行校正Fig.8 Diagrams showing process of diagenesis and tectono-burial evolution of the Cambrian carbonate rocks of Sanhuichang, Nanchuan

5.3 成岩阶段中的流体演化

根据四川盆地地层水资料(马力等, 2004), 寒武系地层水矿化度为38.62~142.31(10³mg/L), $δ^{18} O_{PDB}$ 为-11.34‰ ~-9.34‰ (平均为-10.45‰ ), δ D_PDB为-70.5‰ ~-61.9‰ (平均为-68.2‰ )。将之与寒武纪海水(δ ¹⁸O=-8.0‰ ; δ D=-52‰ ; 马力等, 2004)相比, 存在明显的氧及氘负偏, 反映地层水中有大气淡水渗入。如前述, 裂隙(FC_Ⅱ)、孔洞中的方解石(VC_Ⅱ)及孔洞中白云石(VD_Ⅱ)的 $δ^{18} O_{PDB}$ 为-9.8‰ ~-8.6‰ , $δ^{13} C_{PDB}$ 负偏较明显, 并伴有烃类充注(沥青), 据此推断地层水主要是海西期大气降水成因的溶滤水, 上述缝洞充填物的形成也与此相关。而孔洞中白云石(VD_{Ⅰ -Ⅱ})的有序度低(0.64)、 $δ^{18} O_{PDB}$ 为-11.7‰ , 可能代表了早期大气水的影响。具有强烈 $δ^{18} O_{PDB}$ 、 $δ^{13} C_{PDB}$ 负偏的溶洞方解石(VC_Ⅳ), 发育于燕山期至喜马拉雅期构造褶皱与抬升剥蚀过程中, 是近地表(土壤)有机酸或生物甲烷(细)菌参与的大气水作用的产物。另外, 剖面中未见到周缘及威远气田灯影组中广泛分布中的热改造型氧化沥青、碳沥青, 前者被认为是海西运动的产物, 后者是印支构造期的产物(马力等, 2004), 这进一步佐证了加里东期— 海西期和燕山期— 喜马拉雅期应是大气淡水作用活跃期, 对应于构造抬升期(图 8)发生沿断裂的大气淡水作用。

6 结论

在区域构造— 岩相分析的基础上, 采用岩相学和地球化学方法, 获得了经历长期、复杂的地质演化的下古生界碳酸盐岩成岩阶段及作用的总体认识。主要认识如下:

1)重庆三汇场剖面寒武系白云岩分别经历了早期准同生、中浅层埋藏、中期构造大气水、中晚期埋藏和晚期构造大气水成岩作用。

2)沿向上变浅的高频层序界面发育鲕模孔、窗格溶孔、膏模孔等组构性溶孔, 孔隙胶结物或缝洞充填物具有如下特征: 比同期海水的δ ¹⁸O、δ ¹³C值偏负, 与同期海水的⁸⁷Sr/⁸⁶Sr值相近, 不发光(CL), 一般仅有较小的液相包裹体。这些特征表明其应属于早期大气淡水作用产物。

3)发育非组构扩溶缝孔洞, 伴生氧化的沥青、不发光的充填物, 其δ ¹⁸O、δ ¹³C值偏负, ⁸⁷Sr/⁸⁶Sr值正偏, 出现含烃的低温不混溶包裹体, 并叠加埋藏白云岩化和石英、粗晶白云石等热液作用产物, 故应为加里东晚期— 海西期大气水作用的证据。

4)出现非组构孤立的溶蚀孔洞或缝洞, 多被巨晶方解石或黏土充填, 方解石中δ ¹⁸O、δ ¹³C值强烈负偏、发育低温不混溶包裹体(低于28.5^℃)等, 明显指示其是燕山期或喜马拉雅期大气淡水作用的产物。

致谢陈代钊研究员及2位匿名评审专家提出了中肯的修改意见, 在此深表谢意!

作者声明没有竞争性利益冲突.

参考文献

文献选项

[1]	陈学时, 易万霞, 卢文忠. 2004. 中国油气田古岩溶与油气储层. 沉积学报, 22(2): 244-253. [Chen X S, Yi W X, Lu W Z. 2004. The paleokarst reservoirs of oil and gas fields in China. Acta Sedimentologica Sinica, 22(2): 244-253] [文内引用:1]
[2]	陈宗清. 2013. 论四川盆地下古生界5次地壳运动与油气勘探. 中国石油勘探, 18(5): 15-23. [Chen Z Q. 2013. On five crustal movements and petroleum exploration in Lower Paleozoic, Sichuan Basin. Petroleum Exploration and Development, 18(5): 15-23] [文内引用:2]
[3]	黄思静, 石和, 毛晓东, 张萌, 沈立成, 武文慧. 2002. 重庆秀山寒武系锶同位素演化曲线及全球对比. 地质论评, 48(5): 509-516. [Huang S J, Shi H, Mao X D, Zhang M, Shen L C, Wu W H. 2002. Evolution of Sr isotopes of the Cambrian sections in Xiushan, Chongqing, and related global correlation. Geological Review, 48(5): 509-516] [文内引用:1]
[4]	黄文明, 刘树根, 张长俊, 王国芝, 徐国盛, 雍自权, 马文辛. 2009. 四川盆地寒武系储层特征及优质储层形成机理. 石油与天然气地质, 30(5): 566-575. [Huang W M, Liu S G, Zhang C J, Wang G Z, Xu G S, Yong Z Q, Ma W X. 2009. Reservoir characteristics and formation mechanism of the high quality Cambrian reservoirs in Sichuan Basin. Oil & Gas Geology, 30(5): 566-575] [文内引用:3]
[5]	黄文明, 刘树根, 马文辛, 王国芝, 张长俊, 曾祥亮, 宋光永. 2011. 深层海相碳酸盐岩优质储层的形成、保存和破坏机制: 以四川盆地震旦系—志留系为例. 地质科学, 46(3): 875-890. [Hang W M, Liu S G, Ma W X, Wang G Z, Zhang C J, Zeng X L, Song G Y. 2011. Formation, preservation and damage mechanism of marine deep carbonate high quality reservoir rocks: Illustrated by Sinian system to Silurian in Sichuan Basin. Chinese Journal of Geology, 46(3): 875-890] [文内引用:2]
[6]	金民东, 曾伟, 谭秀成, 李凌, 李宗银, 罗冰, 张静蕾, 刘吉伟. 2014. 四川磨溪—高石梯地区龙王庙组滩控岩溶型储集层特征及控制因素. 石油勘探与开发, 41(6): 650-660. [Jin M D, Zeng W, Tan X C, Li L, Li Z Y, Luo B, Zhang J L, Liu J W. 2014. Characteristics and controlling factors of beach-controlled karst reservoirs in Cambrian Longwangmiao Formation, Moxi-Gaoshiti area, Sichuan Basin, NW China. Petroleum Exploration and Development, 41(6): 650-660] [文内引用:2]
[7]	李皎, 何登发. 2014. 四川盆地及邻区寒武纪古地理与构造-沉积环境演化. 古地理学报, 16(4): 441-460. [Li J, He D F. 2014. Palaeogeography and tectonic-depositional environment evolution of the Cambrian in Sichuan Basin and adjacent areas. Journal of Palaeogeography(Chinese Edition), 16(4): 441-460] [文内引用:1]
[8]	李天生. 1992. 四川盆地寒武系沉积成岩特征与油气储集性. 矿物岩石, 12(3): 66-73. [Li T S. 1992. The characteristics of sedimentary rock and reservoir of oil and gas of Cambrian System in Sichuan Basin. Mineralogy and Petrology, 12(3): 66-73] [文内引用:2]
[9]	李亚林, 巫芙蓉, 刘定锦, 彭勇, 陈胜, 邓小江, 李小娟, 龚富华, 陈华, 甘霞明. 2014. 乐山—龙女寺古隆起龙王庙组储层分布规律及勘探前景. 天然气工业, 34(3): 61-66. [Li Y L, Wu F R, Liu D J, Peng Y, Chen S, Deng X J, Li X J, Gong F H, Chen H, Gan X M. 2014. Distribution rule and exploration prospect of LongWangMiao Fm reservoirs in the Leshan-Longnusi paleolift, Sichuan Basin. Natural Gas Industry, 34(3): 61-66] [文内引用:2]
[10]	刘树根, 孙讳, 李智武, 邓宾, 刘顺. 2008. 四川盆地晚白垩世以来的构造隆升作用与天然气成藏. 天然气地球科学, 19(3): 293-300. [Liu S G, Sun W, Li Z W, Deng B, Liu S. 2008. Tectonic uplifting and gas pool formation since Late Cretaceous Epoch, Sichuan Basin. Natural Gas Geosciences, 19(3): 293-300] [文内引用:1]
[11]	马力, 陈焕疆, 甘克文, 徐克定, 许效松, 吴根耀, 葉舟, 梁兴, 吴少华, 邱蕴玉, 章平澜, 葛芃芃. 2004. 中国南方大地构造和海相油气地质. 北京: 地质出版社, 426-448. [Ma L, Chen H J, Gan K W, Xu K D, Xu X S, Wu G Y, Ye Z, liang X, Wu S H, Qiu Y Y, Zhang P L, Ge P P. 2004. Tectonic of Southern China and Marine Oil and Gas Geology. Beijing: Geological Publishing House, 426-448] [文内引用:5]
[12]	钱一雄, 邹远荣, 陈强路, 陈跃. 2005. 塔里木盆地塔中西北部多期、多成因岩溶作用地质—地球化学表征: 以中1井为例. 沉积学报, 23(4): 596-603. [Qian Y X, Zhou Y R, Chen Q L, Chen Y. 2005. Geological and geochemical implications for multi-period and origin of carbonate karstification in the northwestern Tazhong: Taking well Zhong-1 as an exemple, northwestern Tazhong, Xinjiang. Acta Sedimentologica Sinica, 23(4): 596-603] [文内引用:1]
[13]	钱一雄, 陈强路, 陈跃, 罗月明. 2009. 碳酸盐岩中缝洞方解石成岩环境的矿物地球化学判识: 以塔河油田的沙79井和沙85井为例. 沉积学报, 27(6): 1027-1032. [Qian Y X, Chen Q L, Chen Y, Luo Y M. 2009. Mineralogical and geochemical identification for diagenetic settings of paleo-caves and fractures-filling & vugs calcites in carbonate: Taking wells S79 and S85 for example. Acta Sedimentologica Sinica, 27(6): 1027-1032] [文内引用:1]
[14]	王丹, 陈代钊, 杨长春, Qing Hairuo, 王旭, 吴茂炳, 邢秀娟. 2010. 埋藏环境白云石结构类型. 沉积学报, 28(1): 17-25. [Wang D, Chen D Z, Yang C C, Qing H R, Wang X, Wu M B, Xing X J. 2010. Classification of texture in burial dolomite. Acta Sedimentologica Sinica, 28(1): 17-25] [文内引用:1]
[15]	王剑. 1990. 缓坡及其构造背景: 以中国南方早寒武世龙王庙期扬子碳酸盐缓坡为例. 岩相古地理, (5): 13-22. [Wang J. 1990. Carbonate ramps and their tectonic controls, with an example from the longwangmiaoian(Early Cambrian)YangZi carbonate ramp in South China. Sedimentary Facies and Palaeogeography, (5): 13-22] [文内引用:2]
[16]	王素芬, 李伟, 张帆, 王兴志. 2008. 乐山—龙女寺古隆起洗象池群有利储集层发育机制. 石油勘探与开发, 35(2): 170-l74. [Wang S F, Li W, Zhang F, Wang X Z. 2008. Developmental mechanism of advantageous Xixiangchi Group reservoirs in Leshan-Longnvsi Palaeohigh. Petroleum Exploration and Development, 35(2): 170-174] [文内引用:2]
[17]	张帆, 文应初, 强子同. 1999. 四川盆地寒武系洗象池群碳酸盐岩向上变浅沉积序列. 矿物岩石地球化学通报, 18(1): 23-28. [Zhang F, Wen Y C, Qiang Z T. 1999. Upward shallowing sequences of Cambrian carbonate rocks in the Xixiangchi Group in the Sichuan Basin. Bulletin of Mineralogy, Petrology and Geochemistry, 18(1): 23-28] [文内引用:1]
[18]	周进高, 姚根顺, 杨光, 张建勇, 郝毅, 王芳, 谷明峰, 李文正. 2015. 四川盆地安岳大气田震旦系—寒武系储层的发育机制. 天然气工业, 35(1): 36-44. [Zhou J G, Yao G S, Yang G, Zhang J Y, Hao Y, Wang F, Gu M F, Li W Z. 2015. Genesis mechanism of the Sinian-Cambrian reservoirs in the AnYue gas field, Sichuan Basin. Nature Gas Industry, 35(1): 36-44] [文内引用:2]
[19]	Anderson T F, Arthur M A. 1983. Stable isotopes of oxygen and carbon and their application to sedimentologic and paleoenvironmental problems. In: Arthur M A, Anderson T F, Kaplan I R, Veizer J, Land L S(eds). Stable Isotopes in Sedimentary Geology, 10Tulsa, Okla: Society of Economic Paleontologists and Mineralogists, 1-151. [文内引用:1]
[20]	Denison R E, Koepnick R B, Fletcher A, Howell M W, Callaway W S. 1994. Criteria for the retention of original seawater⁸⁷Sr/⁸⁶Sr in ancient shelf limestones. Chemical Geology, 112(1-2): 131-143. [文内引用:1]
[21]	Goldstein R H, Reynolds T J. 1994. Systematics of fluid inclusions in diagenetic minerals. SEPM Short Course, 31: 199. [文内引用:1]
[22]	Ingram B L, Sloan P. 1992. Strontium isotopic composition of estuarine sediments as paleosalinity: Paleoclimate indicator. Science, 255: 68-72. [文内引用:1]
[23]	Loucks R G. 1999. Paleocave carbonate reservoirs: Origins, burial-depth modifications, spatial complexity, and reservoir implications. AAPG Bulletin, 83(11): 1795-1834. [文内引用:1]
[24]	McCrea J M. 1950. On the isotope chemistry of carbonates and paleo-temperature scale. Journal of Chemical Physics, 18(6): 849-857. [文内引用:1]
[25]	Moore C H. 2001. Carbonate Reservoirs Porosity Evolution and Diagenesis in a Sequence Stratigraphie Framework. Amsterdam: Elsevier Science, 1-234. [文内引用:1]
[26]	Purdy E G, Waltham D. 1999. Reservoir implications of modern karst topography. AAPG Bulletin, 83(11): 1774-1794. [文内引用:1]
[27]	Sam Boggs J R, Krinsley D. 2006. Application of cathodoluminescence imaging to the study of sedmimentar rocks. London: Cambridge Universtiy Press, 109-134. [文内引用:1]
[28]	Sean A G, Mark G, Daniel G C, Andrew M, Gombos J R, Steven L B, David A V. 2007. Karst and early fracture networks in carbonates, turks and Caicos island , British West Indies. Journal of Sedimentary Research, 77(6): 508-524. [文内引用:1]
[29]	Sibley D F, Gregg J M. 1987. Classification of dolomite rocks textures. Journal of Sedimentary Petrology, 57: 967-975. [文内引用:2]
[30]	Veizer J, Ala D, Azmy K, Bruckschen P, Bruh D, Buhla F, Carden G A F, Diener A, Ebneth S, Godderis Y, Jasper T, Korte C, Pawellek F, Podlaha O G, Strauss H. 1999. ⁸⁷Sr/⁸⁶Sr, δ¹³C and δ¹⁸O evolution of Phanerozoic seawater. Chemical Geology, 161(1): 59-88. [文内引用:1]

2004

0.0

陈学时, 易万霞, 卢文忠. 2004. 中国油气田古岩溶与油气储层. 沉积学报, 22(2): 244-253.

[Chen X

, Yi W

, Lu W

. 2004. The paleokarst reservoirs of oil and gas fields in China. Acta Sedimentologica Sinica, 22(2): 244-253]

There widely exists paleokarst reservoir associated with regional unconformitiesduring the oil and gas exploration in China. Based on the analysis of the paleokarst reservoirs in Ordovician gas field in Ordos basin, Ordovician oil/gas field in Tarim basin and Sinian gas field in Sichuan basin, the authors have found that the paleokarst reservoirs in China are common in the following characteristics: (1) The paleokarst zone can be explicitly divided into three subzones in vertical, i.e. the surface remnant karst zone, the vertical vadose zone and the horizontal phreatic zone.(2) The reservoir space is remnant dissolved pores, vugs and fissures. The most favorable reservoir for oil and gas accumulation is the fissure-dissolved vug reservoir. (3)The distribution of paleokarst reservoirs is controlled by paleokarst morphologyand fault fissures. The most favorable place for reservoir development is on karst slopes and in fault belts.(4) Dissolution during deep burial coincides with the maturation of source rocks, hydrocarbon evolution and migration.Porosity enhancement related to the burial organic dissolution takes place just prior to the arrival of hydrocarbons in reservoirs, so it is of economic concern. (5) Karstification and burial organic dissolution are the most important diagenesis for the paleokarst reservoir development. The formeris a prerequesite factor, while the latteris adominant factorin the reservoir construction.The paleokarst reservoiris a new domain for the deep exploration of oil and gas in China.

Hangzhou Institute of Petroleum Geology, CNPC,Hangzhou 310023

在我国油气田勘探中,与不整合面有关的碳酸盐岩古岩溶储层普遍发育,并占有十分重要的地位。着重讨论我国鄂尔多斯盆地奥陶系、塔里木盆地轮南潜山奥陶系和四川盆地震旦系等典型油气田古岩溶储层发育特征与油气关系,指出我国油气田古岩溶储层具有以下几个特征:(1)古岩溶垂向分带明显,地表残积带、垂直渗流—水平潜流带等发育齐全。(2)储集空间主要由岩溶作用形成的半充填或未充填残余溶蚀孔洞缝组成。优质储层类型以裂缝溶蚀孔洞型储层为主,为各大油气田高产、稳产的最重要储层和主力产气层。(3)储层受古岩溶地貌和断层裂缝的控制明显。古岩溶斜坡和断裂发育区,古岩溶发育强烈,是溶蚀孔洞层和储层发育的有利地区。(4)埋藏有机溶蚀作用形成的次生孔隙为有效孔隙,它的发育与烃类的形成、演化和运聚相匹配。(5)古风化壳岩溶作用和埋藏有机溶蚀作用的多期次叠加和改造,是古岩溶储层及油气藏形成的最佳组合模式。古岩溶储层为中国深层油气勘探提供了一个新的勘探领域。

... 陈学时等,2004 ...

2013

0.0

... 陈宗清,2013),且郁南、都匀、广西、云南、东吴、印支、燕山和喜马拉雅等多期构造运动先后叠加(马力等,2004 ...

... 陈宗清,2013),尤其是广西、印支、燕山等运动,对该地区碳酸盐岩储集层或油气藏进行了强烈改造 ...

2002

0.0

黄思静, 石和, 毛晓东, 张萌, 沈立成, 武文慧. 2002. 重庆秀山寒武系锶同位素演化曲线及全球对比. 地质论评, 48(5): 509-516.

[Huang S

, Shi

, Mao X

, Zhang

, Shen L

, Wu W

. 2002. Evolution of Sr isotopes of the Cambrian sections in Xiushan, Chongqing, and related global correlation. Geological Review, 48(5): 509-516]

94 marine carbonate samples were collected from the sedimentary section of Cambrian in Xiushan of Chongqing, the Upper Yangtze Platform, Southwest China. Samples for strontium isotopic analysis were selected by way of the test of cathodoluminescence, observation of thin sections, and analysis of Sr and Mn. The Mn/Sr ratios of all samples presented in this paper are less than 2, and the cathodoluminescence is dull, but the samples from the Cambrian underwent diagenetic alteration to a certain degree, and the plotted points of the thicknesses and 87Sr/86Sr ratios are somewhat discrete. The strontium isotope evolution curve drawn using the data with relatively low 87Sr/86Sr ratios are consistent with other curves based on samples from different areas of the world, supporting the notion of global consistency of strontium isotope composition of marine carbonates. The strontium isotope variations through time reflect the relative importance of global events, and will become a potential useful tool for intrabasinal and interbasinal correlations. According to this fundamental principle, the authors have dated some key points of the Xiushan Cambrian section. The age of the point with an accumulating thickness of 1340 m from the base of the Cambrian System is 503-509 Ma, and that for the point of 1950 m is 496-498 Ma, which should be valuable for determining the boundaries of Middle/Upper Cambrian and Lower/Middle Cambrian.

本文评述了国际上已有的寒武纪海相碳酸盐的锶同位素演化曲线，公布了重庆秀山寒武系海相碳酸盐的锶同位素分析结果，尽管对样品进行了成岩蚀变检测和必要的筛选，但样品仍可能不同程度地经历了成岩蚀变，锶同位素组成与地层厚度投点图显得较为离散，笔者主要利用87Sr/86Sr比值较低的样品建立的寒武纪海水的锶同位素演化曲线在长期旋回上与国际上已公布的同时代锶同位素演化曲线仍具有较好相似性和可比性，说明全球事件是海水锶同位素组成的主要控制因素，海水的87Sr/86Sr比值在盆内对比，盆间对比，以及全球对比中都具有潜在价值。根据锶同位素地层学的基本原理，笔者尝试确定了重庆秀山寒武纪剖面一些关键点的年龄，累积厚度1340m处的年龄为503－509Ma，累积厚度1950m处的年龄为496－498Ma，这对秀山寒武纪剖面下，中寒武统和中、上寒武统界线的确定具有参考价值。

... 黄思静等,2002),反映其主要受海源流体的影响 ...

2009

0.0

黄文明, 刘树根, 张长俊, 王国芝, 徐国盛, 雍自权, 马文辛. 2009. 四川盆地寒武系储层特征及优质储层形成机理. 石油与天然气地质, 30(5): 566-575.

[Huang W

, Liu S

, Zhang C

, Wang G

, Xu G

, Yong Z

, Ma W

. 2009. Reservoir characteristics and formation mechanism of the high quality Cambrian reservoirs in Sichuan Basin. Oil & Gas Geology, 30(5): 566-575]

Based on core observation,thin section identification,geochemical analysis and analysis of inside geode fluid-filling sequence,this paper tries to discuss the formation mechanism of the high quality Cambrian reservoirs in Sichuan Basin.The following results are obtained:shoal facies tract is the foundation of high quality reservoir;gypsum dissolution,fresh-water karstification and meteoric water filtration and dissolution at the early diagenetic stage are the chief mechanisms of the pre-existing vugs in the Cambrian;dissolution of extraneous corrosive fluids in the process of deep burial is the persistent driving force of enlargement of the pre-existing vugs and the formation of new vugs;favorable tectonic position and weak fluid reaction are the prerequisite to the preservation of the pre-existing vugs.

State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu University of Technology, Chengdu, Sichuan 100083, China

通过岩心薄片观察、地球化学分析、及晶洞流体充填序列分析,对四川盆地寒武系优质储层形成机理进行研究。研究表明,滩相沉积相带是优质储层形成的基础,膏溶、淡水岩溶与成岩早期大气淡水渗滤溶蚀是寒武系先存孔洞的主要形成机制,而深埋过程中外源侵蚀性流体溶解作用则是扩溶先存孔洞或形成新孔洞的持久动力,适宜的构造位置与弱的流体反应则为先存孔洞保存的先决条件。

... 黄文明等,2009,2011 ...

... 周进高等,2015),它们的形成主要与滩相沉积作用、兴凯运动时期(寒武纪未)或局部叠加了加里东期的大气淡水岩溶作用、埋藏期白云化作用及TSR溶蚀作用等有关(黄文明等,2009,2011 ...

... 另据黄文明等(2009)的分析结果,合12井、安平1井和丁山1井寒武系中的孔洞白云石的⁸⁷Sr/⁸⁶Sr值分别为0 ...

2011

0.0

黄文明, 刘树根, 马文辛, 王国芝, 张长俊, 曾祥亮, 宋光永. 2011. 深层海相碳酸盐岩优质储层的形成、保存和破坏机制: 以四川盆地震旦系—志留系为例. 地质科学, 46(3): 875-890.

[Hang W

, Liu S

, Ma W

, Wang G

, Zhang C

, Zeng X

, Song G

. 2011. Formation, preservation and damage mechanism of marine deep carbonate high quality reservoir rocks: Illustrated by Sinian system to Silurian in Sichuan Basin. Chinese Journal of Geology, 46(3): 875-890]

Sinian system to Silurian（Lower group）carbonate rocks is generally buried deeper than 3500 m，which belonged to deep carbonate reservoir rocks.Broad tidal flat and shelf depositional environment determined the lower group carbonate rock reservoirs types which were grainstones，crystalline dolomite and fractured limestone.Multiple phases of tectonic movement led to the karst reservoir rocks development in lower group，Sinian，Cambrian and Ordovician paleokarst zone had occurred by the west to east caused by Caledonian movement.Plenty of bitumen in lower group had showed that there widely developed high quality reservoir rocks and formated paleooil pool or paleogas pool.The petrological and geochemical data had showed that camplicated and multistaged diagenesis and fluid infilling had intimate relationship with formation，preservation and damage mechanism of high quality reservoir rocks.In a word，the controlling factors just for the deep carbonate reservoir rocks were as follows： 1)depositional environment had intensely controlling on the Ordovician and Silurian reservoirs rocks，but faintly controlling on the Sinian and Cambrian.2)paleouplift was a prerequisite，and karstification and fractures were as a necessary condition.3)infilling and thermal cracking of hydrocarbon were the main preservation mechanism，and so is moderate recrystallization.Exogenous erosion fluid had very limited effect in deep burial diagenesis.4)compactionpressure solution and cementationinfilling were the most important factor for densitification of reservoir rocks.

State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu University of Technology, Chengdu 610059

四川盆地震旦系—志留系碳酸盐岩普遍埋藏深度超过3〖CS％0，0，0，0〗〖CS〗500 m，属深层碳酸盐岩储层范畴。宽广的潮坪相和陆棚相沉积环境从根本上决定了盆内下组合碳酸盐岩储层岩石类型主要为颗粒碳酸盐岩、晶粒结构白云岩及裂缝性灰岩。多期次的构造运动导致下组合岩溶储层发育，特别是志留纪末期的加里东运动导致从乐山—龙女寺古隆起核部由西向东依次发育震旦系、寒武系和奥陶系古岩溶带。现今下组合储层中广泛分布的沥青表明下组合曾有过广泛的油气成藏过程，形成古油藏或古气藏，亦表明下组合在油气充注时曾普遍发育优质储层。岩石学和地球化学研究表明，复杂多变、期次繁多的成岩演化和流体充注与下组合优质储层的形成、保存和破坏密切相关，总体上，对四川盆地深层海相碳酸盐岩储层而言： 1）原位沉积体系、白云岩化对震旦系和寒武系优质储层发育控制作用弱、仅对奥陶系和志留系具有较强的控制作用； 2）古隆起是优质储层发育的先决条件，表生岩溶与破裂作用为必备条件； 3）烃类流体充注和热裂解作用早期优质储层保存的主要机制，此外，适度的重结晶作用是形成优质储层的持久动力，埋藏过程中外源侵蚀性流体溶蚀作用的储层效应有限； 4）压实压溶作用、胶结充填作用是储层致密的最主要的因素。

... 黄文明等,2009,2011 ...

2014

0.0

... 金民东等,2014 ...

2014

0.0

李皎, 何登发. 2014. 四川盆地及邻区寒武纪古地理与构造-沉积环境演化. 古地理学报, 16(4): 441-460.

[Li

, He D

. 2014. Palaeogeography and tectonic-depositional environment evolution of the Cambrian in Sichuan Basin and adjacent areas. Journal of Palaeogeography(Chinese Edition), 16(4): 441-460]

The Cambrian platform bank or shore reservoir is an important petroleum exploration target in Sichuan Basin,so it is important for the oil and gas exploration to accurately predict the occurrence,reservoir performance and distribution patterns of the sedimentary facies. The study of Cambrian palaeogeography and tectonic-depositional environment is the key to reservoir prediction. Based on the field measurement of profiles,drilling and logging analysis and seismic data,with the thought of mobilistic tectonics-palaeogeography, the maps of the Cambrian tectonic-depositional environment,which can reflect the palaeogeography and basin evolution in Sichuan Basin, have been drawn by analyzing the sedimentary geology conditions,regional well profiles,stratigraphic thickness and sedimentary facies and so on. From the maps it can be seen that it was relatively higher in the west and north,lower in the east and south of Sichuan Basin during the Cambrian. The shore land and tidal flat facies were developed in the western basin; and inner gentle slope,platform and platform marginal shoal facies were developed in the middle and eastern of study area. The response of sedimentary facies evolution in space and time is: the restricted platform in the Meishucun Age of Early Cambrian→clastic platform and deep basin in the Qiongzhusi Age of Early Cambrian → shore-mixd platform in the Canglangpu Age of Early Cambrian→carbonate ramp in the Longwangmiao Age of the Early Cambrian → the evaporation and limited rimmed platform in the Douposi Age of the Middle Cambrian → the mature rimmed platform in the Xixiangchi Age of the Middle-Late Cambrian. Among the above,the Qiongzhusi Formation was a thick bed of source rocks;the Longwangmiao and Xixiangchi Formations were benefied to forming carbonate reservoirs;gypsum rocks formed in the Longwangmiao and the Douposi Formations were good caps.

He DengfaSchool of Energy Resources,China University of Geosciences(Beijing),Beijing 100083

四川盆地寒武纪台地滩相储集体是一套重要的油气勘探目的层,准确预测其发育部位、储集性能与分布规律是其油气勘探的重要基础,其中,寒武纪不同地质历史时期古地理与构造—沉积环境的研究是储集体预测的关键。根据野外实测剖面、钻井和测井分析、地震资料,应用活动论构造—古地理思想,在沉积地质条件、区域连井地层剖面,地层厚度与沉积相等分析的基础上,综合编制了寒武纪各个时期的构造—沉积环境图件,反映了四川盆地寒武纪的古地理特征及盆地演化。四川盆地寒武纪整体呈现西高东低、北高南低的古地理格局,西部发育潮坪和滨岸等碎屑岩沉积相,中东部发育缓坡相、台地相及台地边缘浅滩相等。沉积相在时空上的响应为由早寒武世梅树村期局限台地→筇竹寺期碎屑岩台地和深水盆地→早寒武世沧浪铺期滨岸—混积台地→早寒武世龙王庙期碳酸盐岩缓坡→中寒武世陡坡寺期蒸发局限镶边台地→中晚寒武世洗象池期成熟镶边台地的演化过程。其中,筇竹寺期为巨厚的烃源岩生成期;龙王庙期和洗象池期,为碳酸盐岩储集层发育的有利时期;龙王庙期及陡坡寺期发育的蒸发岩可形成良好的盖层。

... 李皎和何登发,2014) ...

1992

0.0

... 李天生,1992 ...

... 李天生,1992),中寒武统高台组(#cod#x02208 ...

2014

0.0

李亚林, 巫芙蓉, 刘定锦, 彭勇, 陈胜, 邓小江, 李小娟, 龚富华, 陈华, 甘霞明. 2014. 乐山—龙女寺古隆起龙王庙组储层分布规律及勘探前景. 天然气工业, 34(3): 61-66.

[Li Y

, Wu F

, Liu D

, Peng

, Chen

, Deng X

, Li X

, Gong F

, Chen

, Gan X

. 2014. Distribution rule and exploration prospect of LongWangMiao Fm reservoirs in the Leshan-Longnusi paleolift, Sichuan Basin. Natural Gas Industry, 34(3): 61-66]

The Longwangmiao Fm gas reservoir was found in 2012 in the Moxi area in the LeshanLongnüsi Paleouplift, central Sichuan Basin. The previous geological studies showed that the Lower Cambrian Longwangmiao Fm reservoir is mainly of porous pay zones of grain shoal facies, locally superimposed by the vuggy pay zones formed by Caledonian karstification, and the distribution of pay zones has a critical control effect on the reservoir there. To this end, the pay zones in this area were forecasted according to the following features: facies, superimposed karst, highlights, and traps. First, the sedimentary facies served as the basis for defining the favorable facies boundary and karstification influence range; on the basis of the precise comparison between the top and bottom horizons of the reservoir, the favorable development area of the reservoir was then predicted according to the "highlighted" seismic response characteristics of the Longwangmiao Fm reservoir; finally, favorable exploration areas were preferably selected according to the effective reservoirtrap combination. The horizontal change in Longwangmiao Fm reservoir and lithological features resulted in the absence of uniform interface features of the top boundary on the seismic profiles and the difficulty in comparison and tracing. In the actual interpretation process, it was recommended to find out the underlying reference horizon first, then to compare the bottom boundary of Longwangmiao Fm, and finally to interpret it by referring to the method applied to the top boundary. The prediction results indicated that the reservoirs are distributed in a zonal manner in a wide range around the Paleouplift; and the exploration prospects mainly involve three fields: lithologic  stratigraphic traps near the pinchout boundary of Longwangmiao Fm; lithologic traps formed by separate facies; and tectonic and lithologic traps at the north flange of the Paleouplift.

1.Geophysical Prospecting Company of Chuanqing Drilling Engineering Co., Ltd., CNPC, Chengdu, Sichuan 610213, China; 2.Exploration Department of Southwest Oil & Gasfield Company, PetroChina, Chengdu, Sichuan 610051, China

2012年在四川盆地川中地区乐山—龙女寺古隆起的磨溪地区发现了下寒武统龙王庙组气藏，地质研究成果表明，龙王庙组储层主要为颗粒滩相的孔隙型储层，局部叠加了加里东期岩溶作用形成的孔洞型储层,储层分布对气藏具有重要的控制作用。为此,该区储层预测形成了“占滩相、叠岩溶、找亮点、套圈闭”的综合预测思路。首先，根据沉积相确定其有利相带边界和岩溶作用影响范围，在精细对比储层顶、底层位的基础上，根据龙王庙组储层“亮点”地震响应特征来预测储层的有利发育区域；最后，结合储层与圈闭的有效匹配关系实现了有利勘探区带的优选。由于龙王庙组岩性和储层的横向变化，导致其顶界在地震剖面上没有统一的界面特征，对比追踪较为困难，在实际的解释过程中，便采用先寻找下伏参考层，再对比龙王庙组底界，进而对比其顶界的方法进行解释。预测成果表明，龙王庙组储层在古隆起周围区域大范围呈带状分布，勘探区主要有3大领域：①龙王庙组尖灭线附近的岩性—地层圈闭；②单独滩体形成的岩性圈闭；③古隆起北翼的构造、岩性圈闭。

... 李亚林等,2014 ...

2008

0.0

刘树根, 孙讳, 李智武, 邓宾, 刘顺. 2008. 四川盆地晚白垩世以来的构造隆升作用与天然气成藏. 天然气地球科学, 19(3): 293-300.

[Liu S

, Sun

, Li Z

, Deng

, Liu

. 2008. Tectonic uplifting and gas pool formation since Late Cretaceous Epoch, Sichuan Basin. Natural Gas Geosciences, 19(3): 293-300]

The strong tectonic uplifting took place since late Cretaceous epoch in the Sichuan Basin and its peripheral orogenic zones. Except the west Sichuan foreland basin, the whole Sichuan basin was in the state of uplifting since late Cretaceous epoch. However, the uplifting characteristics are diverse in different parts of the basin. The uplifting process could be divided into three stages. The first stage, namely differential uplifting stage, is from the late Cretaceous epoch to the Eogene period. Most of the basin was raised with differential uplift velocities in this stage. The second stage is called the whole basin uplifting stage, with the uplifting rate of more than 40m/Ma and the uplifting height of more than 1 000m. The third stage is the fast uplifting stage with the uplifting height of more than 1 500m and the velocity of more than 100m/Ma except the west Sichuan basin. The Himalayan uplifting is not only to control the formation of the modern structures, but also to adjust the energy field (temperature and pressure) in the basin. The adjustment of the energy made fluids re\|migrate and took an important part in the formation of the natural gas pools in the basin. The hydrocarbon accumulations there from Palaeozoic to Mesozoic, both carbonate and clastic rocks, are also related to the Himalayan uplifting. The big natural gas fields (pools) in the basin have the following characteristics: late finalization, fast formation of hydrocarbon pools, vast quantity accumulation of hydrocarbon, namely fast velocity, large scale and concentrated distribution.

(State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Chengdu University of Technology, Chengdu 610059, China)

四川盆地及其周缘地区在喜马拉雅期发生了强烈的隆升运动。除川西坳陷外四川盆地内部自晚白垩世后一直处于隆升阶段，但各地区有差异，主要的隆升期是新近纪（隆升速率超过100 m/Ma，隆升幅度超过4 200 m），隆升的阶段性明显, 可分成3个阶段：第1阶段（晚白垩世—古近纪），为差异隆升阶段，大部分地区处于隆升状态，但隆升的速率有差异；第2阶段为整体隆升阶段，全盆地都处于隆升状态，整体隆升幅度大，速率一般大于40 m/Ma，隆升幅度超过1 000 m；第3阶段为快速隆升阶段，全盆地的隆升速率除川西坳陷外均大于100 m/Ma，隆升幅度超过1 500m。四川盆地周缘造山带自晚燕山期以来均是隆升状态，亦可分为3个阶段：第1阶段（120~65 Ma），隆升速率15~93 m/Ma，隆升幅度一般在1 000 m左右；第2阶段(65~25 Ma)，隆升较慢，速率一般在5~47m/Ma，隆升幅度为250~1 800 m；第3阶段（25 Ma至今），隆升速率高，为60~300 m/Ma，隆升幅度从1 300 m到大于 3 000 m。喜马拉雅期隆升作用一方面控制了现今构造的形成，另一方面引起能量场调整(压力和温度效应)，促使地层势能的转换和油气的再运聚，对于油气最终运聚成藏起了重要的作用。四川盆地无论中下组合碳酸盐岩气藏还是上组合碎屑岩气藏的形成都与喜马拉雅期隆升作用息息相关, 大型天然气藏具有晚期定型、快速成藏、大量集中聚集的特征，即速度快、规模大、分布集中的天然气爆发式成藏。

... 构造,抬升剥蚀幅度超过4200m(刘树根等,2008) ...

2004

0.0

... 自震旦纪至中二叠世,该地区均为稳定的海相碳酸盐岩台地,先后经历了被动大陆边缘(Z-O)、周缘前缘盆地(P-T₂)和后造山前陆盆地的演化(马力等,2004 ...

... 陈宗清,2013),且郁南、都匀、广西、云南、东吴、印支、燕山和喜马拉雅等多期构造运动先后叠加(马力等,2004 ...

... 3 成岩阶段中的流体演化根据四川盆地地层水资料(马力等,2004),寒武系地层水矿化度为38 ...

... 马力等,2004)相比,存在明显的氧及氘负偏,反映地层水中有大气淡水渗入 ...

... 另外,剖面中未见到周缘及威远气田灯影组中广泛分布中的热改造型氧化沥青、碳沥青,前者被认为是海西运动的产物,后者是印支构造期的产物(马力等,2004),这进一步佐证了加里东期#cod#x02014 ...

2005

0.0

钱一雄, 邹远荣, 陈强路, 陈跃. 2005. 塔里木盆地塔中西北部多期、多成因岩溶作用地质—地球化学表征: 以中1井为例. 沉积学报, 23(4): 596-603.

[Qian Y

, Zhou Y

, Chen Q

, Chen

. 2005. Geological and geochemical implications for multi-period and origin of carbonate karstification in the northwestern Tazhong: Taking well Zhong-1 as an exemple, northwestern Tazhong, Xinjiang. Acta Sedimentologica Sinica, 23(4): 596-603]

Well Zhong 1 is an important discovery well of oil and gas in Ordovician carbonate rocks located at the Northwestern Tazhong up lift. This paper p resents an updated review of the multi-period and origin of carbonate karstification, which took into account of core observation, palaeo-biological analysis, seismic section and mineralogical and petrological and geochemical of calcite cements and calcites in cleavages and cavities or vuges. The two tectonic-related truncation and sedimentary gap surfaces have been identified, which hare some extent of relationship with carbonate karstification in Caledonian, the fact that calcites in cleavages and cavities or vuges in Ordovician carbonate rockswith rather low contents of elements of Fe,Mn, Sr and Ba, and the normal value ofδ 18 O ( - 6. 4‰～ - 4. 5‰) andδ 13 C( - 1. 4‰～0. 5‰) in comparison with that of the average value of seawater of Ordovicianare believed to occurr as a composite results of syngenesis affected by the mixed fluid at shallow buried condition and later meteoric invasion;while the calcite cements developed in Bachu,Donghe formations and Silurian sandstoneswith the ramiform structures of infiltration metasomatism related with magmatic hydrothermalism and the low value ofδ 18 O ( - 10. 5‰～ - 16. 1‰)andδ 13 C ( - 1. 5‰～ - 9. 6‰) indicated it had undergone an intense hydrothermal buried aswell as Hercynian subaerialmeteoric diagenetic change; the low data of strontium isotop ic compositions ( 87 Sr / 87 Sr less than 0. 7100) of filling calcites in cleavages and cavities or vuges in Kalashayi formation and Silurian and Ordovician system of Well Zhong-1 are exp lained as the results of the little effect of continental clastic sediment due to a rather short period of exposure; moreover, itmay be concluded that no similar geological condition or background of a large scale of strong ep igenic karstification exists in the Northwestern Tazhong just as occurred in the Tahei oilfield ( Shaya up lift) with Palocave systemswidely developed in forms of multiple passage caves in the Middle-Upper Ordovician carbonate

1. Department of Resource and Environment , University of Petroleum, Beijing 102200; 2. Western Institute, Exploration & Production Research Institute, SINOPEC,Urumqi 830011

中1井是一口在塔中西北部的奥陶系碳酸盐岩中取得工业油气流突破的重要发现井。对中1井岩心观察、过井的地震剖面、古生物分析和溶蚀—胶结作用成因的矿物学、岩石学及地球化学研究表明中1井T 7 0 (相当于志留系底)、T 7 4 (相当于上奥陶统底)存在两至三个构造削截—沉积间断面,与加里东中晚期岩溶有关;奥陶系碳酸盐岩储层方解石充填物的铁、锰、锶和钡含量相对较低、δ 18 OPDB 为-6.4‰~-4.5‰,δ 13 OPDB 为-1.4‰~0.5‰,87Sr/86Sr平均为0.7092;而石炭系巴楚组膏岩、东河砂岩、志留系碎屑岩中的方解石胶结物δ 18 OPDB 为-10.5‰~-16.1‰、平均为-13.9‰,δ 13 OPDB 为-1.5‰~-9.6‰、平均为-4.8‰; 87 Sr/ 86 Sr为0.7090(志留系)、0.7091(石炭系);研究表明奥陶系碳酸盐岩具有准同生期、浅埋条件下混合水以及较短暴露期下大气淡水下的表生溶蚀的多种复合成因,而志留系和石炭系具有大气淡水溶蚀—充填或埋藏成岩作用特征,海西晚期发生了热液—热水交代有关的溶蚀作用; 87 Sr/ 86 Sr均低于0.7100,表明中1井区经历的大气淡水条件下暴露期相对较短,陆源物质影响较小,因而不具备沙雅隆起海西早期发生的大规模表生岩溶地质条件。

... 钱一雄等,2005,2009) ...

2009

0.0

钱一雄, 陈强路, 陈跃, 罗月明. 2009. 碳酸盐岩中缝洞方解石成岩环境的矿物地球化学判识: 以塔河油田的沙79井和沙85井为例. 沉积学报, 27(6): 1027-1032.

[Qian Y

, Chen Q

, Chen

, Luo Y

. 2009. Mineralogical and geochemical identification for diagenetic settings of paleo-caves and fractures-filling & vugs calcites in carbonate: Taking wells S79 and S85 for example. Acta Sedimentologica Sinica, 27(6): 1027-1032]

Based on observation of core of the Middle and Lower Ordovician carbonate in Wells S85 and S79, a wide rangegeochemical methods has been used to characterize the diagenetic settings of paleocaves and fractures filling & vugs calcites and to decipher their origin, which includes Xray diffraction of crystal cell, carbon and oxygen isotope composition, fluid inclusion, hydrogen isotope of fluid inclusion and chemical elements analysis. Two diagenetic environments are defined and believed to be prevailing in the formation of paleocaves and fractures filling & vugs calcites. the first is diagenetic environment with prevailing hypergen fresh water, mostly related to phreatic zones in subaerial process and of characteristic of crystal cells c=17.057~17.062 and Fe2O3＝0.06%~0.07%，Sr=53.3×106~96.2×106,Ba=19×106~28×106，Mg/Ca(×103)＝1.94~5.14，Sr/Ba＝2.12~5.24 , the lowest values of δ18OPDB (15‰~17‰) , the considerable lower values of δ13C PDB (4‰~2‰) for calcites, without or with few hydrocarbon inclusions and δD PDB＝94.99~109.54‰ of its fluid inclusion; the second is believed to occur in freshwaterseawater mixing and formed during some degree of burial environment, and of features of crystal cell parameters (c)=17.064~17.065(exceptional for 17.212),the considerable high values Fe2O3＝0.06%~0.18%，Sr=111×106~208×106、Ba=215×106~479×106，the considerable lower ratios Mg/Ca(×103)＝1.53~1.76，Sr/Ba＝0.49~0.58 for calcites, the lower values of δ18OPDB (9.6‰~13.7‰)for calcites, the considerable higher δD PDB＝77.5‰~88.2‰ of fluid inclusion. In addition, the study also demonstrated that differential hydrogeochemical systems had been developed in the formation of the gigantic speleothem calcite crystal at the 5 960～5 966 m depth of burial with more than 6 m in height palaeocave in Well S85 in Tahe oil field.

Wuxi Petroleum Geology Institute, Exploration & Production Institute, SINOPEC, Wuxi Jiangsu214151

摘要在塔里木盆地塔河油田4区沙79井、6区沙85井奥陶系鹰山组岩芯的详细观察基础上，对裂隙、溶洞及巨型洞穴中的方解石晶体的晶胞参数、化学成分、碳、氧同位素、流体包裹体中的氢同位素等分析与研究表明，至少存在两种成岩环境：一是以大气淡水表生环境，方解石中晶胞参数(c)=17.057~17.0 62，Fe2O3＝0.06%~0.07%，Sr=53.3×10-6~96.2×10-6、Ba=19×10-6~28×10-6，Mg/Ca(×103)＝1.94~5.14，Sr/Ba＝2.12~5.24，δ18OPDB较低（-15‰~-17‰）、较低δ13CPDB（-4‰~-2.0‰），不含或较少含烃类，流体包裹体中氢δDPDB＝-94.99‰~-109.54‰为特征；另一是地层混合水埋藏环境为主，方解石中晶胞参数(c)=17.064~17.065（个别达17.212）、Fe2O3＝0.06%~0.18%，Sr=111×10-6~208×10-6、Ba=215×10-6~479×10-6，Mg/Ca(×103)＝1.53~1.76，Sr/Ba＝0.49~0.58，方解石δ18OPDB低（-9.6‰~-13.7‰）、流体包裹体中氢δDPDB＝-77.5‰~-88.2‰为特征；另外，在巨型洞穴中方解石中组分的剧烈变化反映了洞穴充填发生于不同的水文地质—地球化学体系。

... 钱一雄等,2005,2009) ...

2010

0.0

王丹, 陈代钊, 杨长春, Qing

Hairuo

, 王旭, 吴茂炳, 邢秀娟. 2010. 埋藏环境白云石结构类型. 沉积学报, 28(1): 17-25.

[Wang

, Chen D

, Yang C

, Qing H

, Wang

, Wu M

, Xing X

. 2010. Classification of texture in burial dolomite. Acta Sedimentologica Sinica, 28(1): 17-25]

In recent years, a great progress in hydrocarbon exploration has been achieved in dolomite reservoirs in which several large scale hydrocarbon pools were discovered in China. In view of which most of these dolomite reservoirs were formed during burial period, together with the high abundance of burial dolostones in stratigraphic columns, this paper aims to focus on classification of genetic texture in burial dolomite without consideration for relatively simple textures of primary or penecontemporaneous micritic dolomite. In international academic community, the classification of genetic texture of burial dolomite were well documented, but were less paid attentions in Chinese academic circle. In order to improve further study in this field, it is necessary to distinguish the different textures of dolomite formed in buried period, so that to understand the different characters of dolomization liquid. We here introduce a modified classification scheme for genetic texture of burial dolomite with references of classification about this field in international academe and combining the actual situation of dolomite researching in China. First of all, on the basis of dolomite occurrence, the dolomite texture is divided into two types: matrix dolomite and cement dolomite, Then according as crystal size, crystal shape, crystal surface and contact relation, burial dolomite is classified into six types, in which four are matrix: 1)finely crystalline, planare(s), floating dolomite; 2)finely crystalline, planare(s) dolomite; 3)finelycoarsely crystalline, nonplanara dolomite matrix; 4)coarsely crystalline, nonplanar saddle dolomite matrix, and the remanent two are cement: 1)finelymedium crystalline, planare(s) dolomite cement; 2)coarsely crystalline, nonplanar saddle dolomite cement. These texture classification provides a basis on which the dolomites formed in different diagenetic stages can be sorted out properly in the context of physicalchemical conditions of dolomitisiting fluids from which they formed，which provides effective approach of dolomite studying.

Institute of Geology and Geophysics, Chinese Academy of Science, Beijing 100029

近年来我国在白云岩储层油气勘探方面取得了重大进展，这些白云岩储层绝大多数为埋藏阶段形成的白云岩，同时大量研究也证实地层中大部分白云岩形成于埋藏环境。国际学术界对埋藏环境白云石的成因结构分类比较细致，但在我国这方面的研究还不够深入，因此本文借助国际上对埋藏环境白云石成因结构的分类方法，并结合中国白云岩研究的实际情况尝试提出埋藏环境白云石结构分类方案。该方案首先以白云石在岩石中的产状分为基质白云石和胶结白云石两大类，再以晶粒大小、晶型、晶面特征、接触关系为分类依据，将埋藏环境白云石分为六种结构类型。

... 由于白云岩为研究区的主要岩类,且各种残余藻结构较为发育,因此笔者依据Sibley和Gregg(1987)、并参考王丹(2010)的白云石分类方案,按残余藻结构、晶体大小、晶形及晶面接触关系等多因素,对三汇场剖面的白云岩进行了分类 ...

1990

0.0

... ₃m)(或称之为娄山关群),上覆下奥陶统桐梓组(O₁t)(王剑,1990 ...

... 潮坪沉积(王剑,1990 ...

2008

0.0

王素芬, 李伟, 张帆, 王兴志. 2008. 乐山—龙女寺古隆起洗象池群有利储集层发育机制. 石油勘探与开发, 35(2): 170-l74.

[Wang S

, Li

, Zhang

, Wang X

. 2008. Developmental mechanism of advantageous Xixiangchi Group reservoirs in Leshan-Longnvsi Palaeohigh. Petroleum Exploration and Development, 35(2): 170-174]

Abstract The Leshan–Longnüsi palaeohigh in the Sichuan Basin controlled by basement uplift underwent multistage or multicyclic syndepositional uplifting and denudation uplifting during evolvement. Carbonate reservoirs are developed in the Lower Upper Cambrian Xixiangchi Group in this area. The reservoirs are compact and have low matrix porosity and permeability. But porous and dissolution layers exist locally, and porous layers commonly occur in pinhole and coarse textural dolomites. Fracture growth may improve the reservoir penetration conditions. Karstification in the depositional and weathering stages is the main diagenesis of the reservoirs. The main developmental zones of excellent reservoirs are palaeo-karst crust of weathering and the area where karst ramps and structural fractures coexist.

... 王素芬等,2008 ...

... 磨溪下寒武统龙王庙组大气田的碳酸盐岩储集层研究表明,颗粒滩相的孔隙型储集体发育粒内溶孔、粒间溶孔、晶间孔及溶孔、膏溶孔、裂缝等储渗空间(王素芬等,2008 ...

1999

0.0

张帆, 文应初, 强子同. 1999. 四川盆地寒武系洗象池群碳酸盐岩向上变浅沉积序列. 矿物岩石地球化学通报, 18(1): 23-28.

[Zhang

, Wen Y

, Qiang Z

. 1999. Upward shallowing sequences of Cambrian carbonate rocks in the Xixiangchi Group in the Sichuan Basin. Bulletin of Mineralogy, Petrology and Geochemistry, 18(1): 23-28]

Research on the data from the crops and driling cores suggests that middle and upper Cambrian carbonate rocks of the Xixiangchi group in the Sichuan Basin consist of the 16 microfacies.Associations of the dif erent microfacies make up the distinct upward shallowing sedimentary sequences.Four types of upward shallowing sequences with thickness in meters can be ident ified,evidently dif erent in the contents of the terrigenous clastics and grains,size trend and thickness also in the values of C and O isotopes.They were deposited on the dist inct seting.Various shallowing sequences constitute a shallowing cycle,which is characteristic of the Xixiangchi group,inferring that their sedimentary environment was an epicontinental carbonate platform with very shallow waters and gently topography.

四川盆地中寒武世陡坡寺期以后,开始了以碳酸盐为主的沉积,形成一套数百至上千米厚的碳酸盐岩.该套沉积以浅灰、灰、灰黄色白云岩为主,盆地东北及东南部夹灰岩.其中下部普遍夹灰黄、紫红色砂岩、粉砂岩、泥岩薄层,具石膏假晶,邻水、永川、泸州等地夹膏盐层;其上部较纯,近顶部多含燧石结核及条带.由于该地层至今还未发现可靠化石,进一步划分有困难,故统称为洗象池群(2 2+3 ),厚600~1 500 m.经对4条露头剖面及8条钻孔剖面的研究(图1),洗象池群可划出16个微相,两类4种向上变浅沉积序列,为不同沉积背景的产物.

... 张帆等,1999 ...

2015

0.0

... 周进高等,2015) ...

1983

0.0

... )具有特别低的 δ13CPDB值,应是细菌快速氧化有机碳形成的CO₂产物,反映了潮湿环境下土壤有机质参与的大气水岩溶作用(Anderson and Arthur,1983) ...

1994

0.0

... Denison et al ...

1994

0.0

1992

0.0

... 7093,Ingram and Sloan,1992 ...

1999

0.0

... 而碳酸盐岩表生大气水岩溶作用的环境分析及期次判识,却对明确储集层形成及其与油气充注和保存的关系具有重要意义(Loucks,1999 ...

1950

0.0

... 碳氧稳定同位素测试由国家地质实验测试中心完成,测试中采用McCrea(1950)100%正磷酸法处理样品,即: 首先将样品置于恒温箱中烘干,然后在真空中与100%的正磷酸反应,平衡温度50℃,平衡时间24 h ...

2001

0.0

... Moore,2001 ...

1999

0.0

... Purdy and Waltham,1999 ...

2006

0.0

2007

0.0

1987

0.0

... Veizer et al ...

1999

0.0