四川盆地中部上三叠统香溪群岩性油气藏
圈闭类型及其特征*附子种植
杨晓萍 邹才能 李 伟
（中国石油勘探开发研究院，北京100083）
摘 要：四川盆地川中地区构造平缓，大型断裂欠发育，已发现的油气藏与背斜关系并不十分密切。研究认为，川 中地区香溪群主要发育岩性圈闭，根据圈闭形成主控因素，结合香溪群沉积前的古地貌特征和裂缝发育特点，将川中香 溪群岩性圈闭划分为4种类型:①与地层尖灭相关的地层—岩性圈闭；②与沉积—成岩相变密切相关的成岩—岩性圈闭; ③与古地貌有关的差异压实作用形成的岩性圈闭;④与断层转化调节相关的裂缝—岩性复合圈闭。其中成岩—岩性圈闭 和地层—岩性圈闭，是川中香溪群最重要的、分布最广泛的圈闭类型。
关键词：圈闭类型；岩性油气藏；上三叠统；四川盆地
中图分类号：TE112.3 文献标识码：A
川中香溪群天然气勘探始于1956年，截至2004
年
底，获天然气探明储量377.98×108m 3，控制储量
167.48
× 108m 3，预测储量 429.73 × 108m 3。尽管在过去近50
年的勘探历程中有248口井钻遇香溪群，但从钻探程度
看，主要钻探工作集中在八角场、磨溪和遂南等构造圈
闭上（图 1），川中香溪群的油气勘探目前仍然以构造
油气藏勘探思路为主导。由于川中地区总体构造平缓，
西南马
大断裂不发育，而且在已经钻探的构造圈闭中，经常会
出现构造高部位出水、构造低部位反而含气、油气水关
系倒置的现象。因此需要特别重视岩性地层油气藏存
在的巨大潜力。 川中地区香溪群从下向上划分为香一至香六共6个 层段，香一、香三、香五段为湖沼相泥岩夹薄煤层，香
二、香四、香六段为三角洲分流河道砂岩，空间上形成
非常有利的生储盖配置，而且多旋回的湖进湖退沉积
背景是岩性油气藏发育的最有利条件。因此，在川中地 区，乃至整个四川盆地上三叠统的油气勘探中，应加强
岩性油气藏的成因机理、主控因素、分布规律等方面的 图１ 四川盆地构造分区图 Fig.1 Map shows th
e tectonic division of Sichuan Basin 研究，
转变勘探思路，提高钻探成功率和勘探效益。 研究认为，控制川中香溪群油气藏形成最重要的 ＊基金项目：中国石油天然气股份有限公司科技项目“岩性地层油气藏勘探理论与实践”。
第一作者简介：杨晓萍，女，高级工程师，从事沉积储层及石油地质综合研究工作。
收稿日期：2006-05-15
33 No.4 2006 China Petroleum Explo-
风俗通义
石油地质
两个因素是烃源岩和圈闭。据最新资源评价结果，四川 盆地中西部地区具有很好的生烃条件[1]，川中地区大部 分生烃强度大于 20 × 108m 3/km 2。因此，圈闭的类型、 形成条件及其分布规律是急需深入研究的问题，特别 是有效圈闭的形成与分布需要引起高度重视[2]。通过对 川中香溪群储层的沉积相、岩石相、成岩相，以及香溪 群沉积前的古地貌、香溪群与下伏层构造形态、气藏类 型等综合研究，认为成岩—岩性圈闭和地层—岩性圈 闭是川中地区香溪群的主要圈闭类型，它们的形成与 分布对油气聚集成藏起了重要的控制作用。 根据影响有效储层形成与分布的主控因素，结合 香溪群沉积前的古地貌特征和裂缝发育特点，将川中 香溪群岩性圈闭划分为4种圈闭类型:①与地层尖灭相 关的地
层—岩性圈闭;②与沉积—成岩相变密切相关的 成岩—岩性圈闭;③与古地貌有关的差异压实作用形成 的岩性圈闭;④与断层转化调节相关的裂缝—岩性复合 圈闭。其中与沉积—成岩相变密切相关的成岩—岩性 圈闭是川中香溪群广泛分布的圈闭类型。 1 地层—岩性圈闭
根据地震和钻井资料证实，川西地区须二段储层 （T 3x 2）往川中方向是尖灭的（图2），其尖灭位置大约 在遂宁—蓬溪—蓬安一线[3]。沿此尖灭线形成了两个大 型地层—岩性圈闭：一为西段（以沱江为界）的踏水桥 —柳树沱地层圈闭，由-2750m 等高线与尖灭线闭合而 成，面积为 597.8km 2，闭合度为 450m ；另一个为东段 的文井场—泸溪场复合圈闭，它除了由－ 2800m 等高
线与尖灭线闭合而形成地层圈闭外，其中还存在着一 系列面积和幅度差异很大的次级圈闭，小断层也比较 发育，该复合圈闭面积为 361.7km 2，闭合度为 390m 。 两圈闭的总闭合面积达959.5km 2，几乎占据了整个尖 灭带，规模比较大，为形成大中型气田提供了一个广阔 的油气富集场所。
2 成岩—岩性圈闭
成岩—岩性圈闭与沉积—成岩相变密切相关。川 中香溪群沉积相研究表明，在香二段、香四段和香六段 中，砂岩累计厚度一般在70～130m 之间，由三角洲平 原分支河道或三角洲前缘水下分流河道叠置砂体组成，
岩性由含砾粗砂岩、中—粗砂岩和中—细砂岩组成，含
少量粉砂岩和碳质泥岩[4]。
如果以6%为有效储层的下 限值，
根据岩心实测孔隙度和测井解释孔隙度统计，其 有效储层单层厚度一般为
3～5m, 纵向上常常被致密 的中—细砂岩相隔，横向上连通性差，储层非均质性 强。显然，这是成岩作用造成的结果，强烈的压实—压 溶作用和部分胶结作用，使岩石颗粒较细、杂基含量（8％～ 10%）较高的中—细砂岩成为致密层。川中地区香二、 香四段大段砂岩层中，由于差异压实成岩作用形成的
不同成岩相，使其中的有效储层，剖面上呈透镜状、似 层状，
平面上呈带状，分布在相对致密的砂岩中，有效 砂岩储层呈不规则形态，
内部储集性能较好，外围成岩 相变和部分沉积相变为致密的封堵岩石。
这种由于沉 积—成岩相变形成的成岩相圈闭，
在川中地区香二、香 四段储层中分布非常普遍，
续写变色龙是川中地区最主要的圈闭 类型（图
3）。 图2 川中—川西过渡带形成的须二段地层—岩性圈闭分布模式图
Fig.2 Distribution pattern of stratigraphic-lithologic traps in the 2nd member of Xujiahe Formation formed in the
transition zone between the central and western Sichuan areas
34
t的短语图3 川中地区香溪群成岩—岩性圈闭分布示意图
Fig.3 Distribution of diagenesis-lithologic traps in Xiangxi Group in the central Sichuan area
在香二段（T3h2）超覆沉积时，三角洲平原分支河道砂
体向残丘斜坡超覆尖灭，后期差异压实有利于形成披
覆构造的以尖灭砂体为主体的岩性圈闭。遮挡层是香
二砂体上下的泥岩层。在川中南部的磨溪地区，香二段
中部和底部，有10～30m 的页岩层发育。由于下倾方
向缺乏岩性封堵，所以，沿着现今构造区域倾斜方向的
古残丘斜坡部位有利于气的聚集和气藏的保存。另外，
如果古残洼中直接被香二段的古河道砂体充填（图4
(b)），上面被页岩层覆盖，下垫以雷口坡组可风化和溶
蚀的致密层，便形成以粗碎屑岩体为主的岩性圈闭。
与古地貌有关的差异压实作用形成的岩性圈闭，
由于主要受古地貌控制，残丘高度有限，香二段受其控
3 与古地貌有关的差异压实作用形成的
岩性圈闭
上三叠统香溪群（T3h）沉积前，由于印支早幕的
影响，在上扬子地区形成隆坳相间的构造格局。研究区
处于其中的泸州—开江古隆起的西北斜坡部位，由于
构造抬升和差异溶蚀剥蚀，香溪群的下伏地层形成了
北东向的残丘和残洼相间分布，有多个幅度达40～
90m的古残丘[5]。这种岩溶古地貌在一定程度上控制了
香溪群早期的沉积及其后的差异压实作用，并形成了
与岩溶古地貌相关的岩性圈闭（图4）。
图4(a)为古残丘斜坡上差异压实形成的岩性圈闭。
图4 川中香溪群与岩溶古地貌相关的岩性圈闭示意图
Fig.4 Sketch map shows lithologic trap related with karst palaeo-geomorphology in Xiangxi Group
in the central Sichuan area
Expl o-
上海dns
石油地质 制更明显。图4(a)型主要分布在磨溪—遂南—龙女寺一 带古残丘发育区；图4(b)型主要分布在安岳—通贤一带 底页岩发育区；通贤一带香二段砂岩的孔隙度为 10%～ 15%，渗透率为(0.2～0.8)×10-3μm 2，可见砂体内具有一 定储渗条件。 4 与断层转化调节相关的裂缝—岩性复 合圈闭 川中地区香溪群尽管大断层不太发育，但下伏雷 口坡碳酸盐岩地层中，大断层很多[6]。在研究区的东南 缘，靠近华蓥山断裂带，下伏断层更发育，形成北东向 的断层带，向上一般逐渐消失于香溪群底界之下。断层 带上部，在香溪群可形成鼻褶带、膝褶带和微破裂带 等，这些部位常常形成裂缝—岩性复
合圈闭。川中东部 的界市场气田、灵音寺、河包场、荣隆场和高升场等含 气构造，都属于这种复合圈闭。
5
结 语 川中地区背斜构造平缓，大型断裂欠发育，已发现
的气藏和显示井与背斜关系并不十分密切。研究认为，
川中地区存在大量岩性圈闭，特别是与沉积—成岩相 变密切相关的成岩—岩性圈闭是该区油气聚集的有利 场所。即使在燕山期古构造上形成的构造圈闭（如八角
场构造、磨溪—遂南构造），由于其有效性仍然强烈受 到有利岩石相和成岩相的影响，所以这种构造圈闭应 属于构造—岩性圈闭范畴。因此，在川中地区进一步的 油气勘探和成藏规律研究过程中，应该转变思路，运用 岩性地层油气藏的勘探思路，对岩性油气藏加大研究 和勘探力度。
参考文献 [1] 童崇光，等.四川盆地构造演化与油气聚集[M].北京：地质
出版社，1992 [2] 罗志立，等.四川盆地天然气勘探有利地区和新领域探讨[J].
天然气工业，2000,20(4):10～13,(5):4～8
[3] 罗启厚，等.四川盆地中西部三叠系天然气富集条件[J].天
然气工业，1996,16(增刊):40～54
[4] 李耀华，等.川中—川西地区上三叠统储集条件研究[J].天
然气勘探与开发，2003,23(3):1～6
[5] 陈立官，等.川中香溪群与差异压实有关的非构造裂缝储层
[J].成都地质学院学报，1991,18(1):120～123
[6] 王洪辉，陆正元.四川盆地中西部上三叠统砂岩非构造裂
缝储层[J].石油与天然气地质，1998,19(1):35～41 图5 川中地区香溪群裂缝—岩性复合圈闭模式图
Fig.5 Composite-trap pattern of fracture-lithologic
with small faults in Xiangxi Group in the central
Sichuan area
2006 年第 4 期 36
ABSTRACT
paleo-uplift, upper slope and down slope and deep depressing. The rearch results indicate that the oil and gas distribution of marine paleo- uplift is f eatured by complex accumulating, various paleo-uplif ts have favorable geologic conditions to discover large oil and gas fields
Key w o rds: marine paleo-up l ift; cratonic basin; types of p a leo-uplift; rervoir-forming o f oil and g a s; large oil and gas field
Trap Types and T h eir Ch a racteristics of Litholog i c Oil-gas Rervoirs in Xiangx i Group in Up per Triassic, Central Sichuan Basin/ Y ang Xiaoping, Zou Caineng and Li Wei//PetroChina Rearch Institute of Petroleum Exploration and Development,Beijing100083 Abstract:There are veral gen t le structure traps and small faults develo p ed in central Sichuan Basin, some discovered oil-gas rervoirs are not related to anticlines. It is thought through related rearch that the lithologic traps mainly developed in Xiangxi Group. According to the factors that controlled the formation of traps , paleo-geomorphology feature before Xiangxi Group deposition and fracture feature, lith o logic trap typ e s can be divided to four typ e s, including: (1) stratigrap h ic-lith o logic trap is related with strati
运动会作文graphic pinch out;(2) diagenesis-lithologic trap is related with the facies variation of deposition and d i agenersis;(3) differential compaction-lith o logic trap is related with paleo-geom o rphology;(4) fracture-lithologic trap is related with the transformation and adjustment o f faults. Among thes, diag e nesis-litholo gic trap and stratig r aphic-litholo gic trap are regarded as th e most important and extensive typ e distributed in cen t ral Sichuan Basin.
Key w o rds: trap type; lithologic oil-gas rervoirs; Upper Triassic; Sichuan Basin
Thermal Simulation Experiment on Generation of Oil-ga s and H2S from Marlite in Lower Triassic Feixianguan Forma t ion in Northwestern Sichuan/Li Jian,Xie Zen gye,Zhang Guangwu,Li Zhisheng and Wang Chunyi//Langfang Branch,PetroChina Rearch Institute of Petroleum Exploration and Development;Langfang City, Hebei Province065000
Abstract: In consideration of the characteristics of high-maturity and low organic matter abundance of Feixianguan Formation carbonate rock s foun d in Sichuan Basin,thermal simulation experiments has carried out on marlite samples collected fro m the fresh o u tcrop s of Feixiangu a n Form a tion,L o wer Triassic,at Shangsi,Jiang e C o unty,N o rth w est S i chu a n. Not on l y revealed the evolving process and characteristics of hydrocarbon generation but also provided important paramet
er for th e external estimatio n of Feixianguan Formation marls in Sichuan Basin. According to the results, the maximum yield ratio of oil hy d rocarbon was up to 142.2kg per ton and the figure of R o (0.63%~1.2% ) is the peak of oil generation; and the maximum yield ratio of gas hydrocarbon was up to 793.9 cubic meters per t on, and the H2S has been detected by the instrument of Agilent 6890N TCD in the gas collected from the different simulation temperature. All of the indicate that the marlite source rocks are of great hydrocarbon- generating potential and H2S under suitable maturity conditions in Sichuan Basin.
Key words: marlite s ource rock; thermal s imulation experiment; hydrocarbon- generating ratio; H2S; n atural gas; F eixianguan formation; Sichuan Basin Sequence S tratigraphy and V ertical Sequenc e of Sandbodies Distribution in Lower Cretaceous Formations in Erlian Basin/ Fang Jie1, Zhao Wenzhi1 and Miao Shunde2//1PetroChina Rearch Institute of Petroleum E x ploration and Development, Beijing 100083; 2 China Un i versity of Geosciences, Beijin g 100083
Abstract: Erlian basin is a rift lacustrine basin developed on the Hercynian geo s yncline folded ba in Early Cretaceous, is featured by simp l e dimentary feature, depositional cycle, small lacustrine tran s gressive, dry climate, salinizatio n lacustrine water and multi-and- near sources. On the basis of quence stratigraphy analysis of Bayindulan sag, Wuliyasitai d e pression, Jierg a langtu sag and
S a ihantala sag, the integrated q uence stratigraphy ctio n o f lo wer Cretaceou s has b een established an d the v ertical quen ce of sand bodies distribution in th ree-ord er quence has been co nclu ded. The main conclusio ns are as fo llo ws: Firstly, und er the influence of three phas of ep i sod i c activities, three tw o-order quences is compod of three depositional cy c les and three reg ional unconformities; Secondly, under the control of structure activities such as fault-block activities and the influence of th r ee-order climate cycles and source recharg e , lower Cretaceous can be d ivid ed into six three-ord er quence; Thirdly, becau fau lt activ ities is weak and fau lt slope is gently , fan deltas exist in steep slopes in early an d later stages an d subaqu eous fan s exist and turb idite fans exist in trou ghs in m iddle stage. Fan deltas distributed in g e ntly slo p es and braided river deltas develop alternately in all stages.
Key w o rds: qu e nce stratigraphy; vertical quence of sandb o dies distribution; Lo w er Cretaceous; Erlian basin
A pplication of Fluid Inclusion in Oil-gas Exploration/Tao Shizhen, Zou caineng and Y uan Xuanjun//PetroChina Rearch Institute of Petroleum Exploration and Development, Beijing 100083
Abstract: Bad on m atrix mineral, diagenetic quence and fluid inclusion s, are tested h omotemp
rature, salinity and flu orescence of inclusions which coexist with hydrocarbon inclusions. The depth and geological age of oil inpouring are ascertained by combining with paleotemperature grad and dimen tary burial history. Inclusio n analysis indicates that Fux in uplift and C hanglin g sag parate away after major rervoir-forming stage of Fuyu oil layer, i.e. oil inpou r ing and rervoir-forming take place before Fuxin uplift upheaved in great force. T he rervoir-fo rmin g of Fuy u oil layer includes tw o stages, i. e.the later Nen jian g period an d later Ming shui period in Cretaceous. Inclusion study demonstra tes oil rervoir being featured by up-source and down-storage, local-storage and vertical migration. It is clarified that the source of Fu yu oil layer mig ht originate anciently from Chan gling sag. Synch ronously , it is pointed out that the "sweet point" controlled by source rock, overpressure, fault and sandbody are advantageous regions for o i l exploration in the future. Key w o rds: fluid Inclusion; rervoir forming p e riod; rervoir-forming mechan i sm ; oil-gas exploration; Fuxin uplift Characteristics and Recognit ion of Biodegradation Gas of Heavy Oil and I ts Exploration Potentia l/Zhu Guangyou, Zhao W enzhi, Zhang Shuichang, Zou Caineng, Wang Zhengjun// Petr oChina Rearch Institute of Petroleum Exploration and Development, Beijing 100083 Abstract: Biodegradation gas of heavy oil, belongs to condary biogenic gas, is originated from the anaerobes biodegradation of crude oil. Generally, degradation gas of heavy oil occurs in shallow rerv o irs and may be accumulated in large scale, so it has good resources potential. B i o
degradation gas of h e avy oil has cloly associated with heavy o i l, in other wo r d, the majority of biodegrad a tion gas of heavy oil distrib u te arou n d the oilfield . B i odegrad a tion g a s o f heavy oil is mainly comp o d of methane, and just a little of heavy hydrocarb o n, also the content of N2 is high in nonh y drocarbon. The carbon isotope v a lue of methane shows the features of high minus value with being around -100‰to-55‰While the CO2 shows unusual heavy carbon isotope value, so it is easy to be recognized. Methane would be generated from heavy oil anaerobic biodegradation, the process of biodegradation run through multi-tache, which was regarded
e t r o l e u mE x p l o r a t i o n
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