PDF(10834 KB)
PDF(10834 KB)
PDF(10834 KB)
川西中部中三叠统雷口坡组白云岩储层成岩作用研究
Diagenesis of dolomite reservoir of the Middle Triassic Leikoupo Formation in central Western Sichuan Basin
储层成岩作用影响孔隙发育、分布及储层质量。基于岩心和薄片观察、白云岩有序度分析、流体包裹体和碳氧稳定同位素等资料，系统开展了川西中部雷口坡组成岩作用研究。研究表明：①雷口坡组白云岩主要包括2种岩石类型：泥晶白云岩和泥晶藻砂屑（藻纹层）白云岩。白云石晶体有序度低、形成温度低，为准同生期白云石化作用形成。储集空间主要是沿藻格架、粒间孔及构造角砾间基础上发育的溶孔。②雷口坡组白云岩主要经历了破裂作用、白云石化作用、去白云石化作用、溶蚀作用、泥晶化作用、胶结作用、表生去膏化作用等成岩作用类型，其中构造破裂作用和溶蚀作用对储层物性起着改善作用，而深部溶蚀是深部次生孔隙发育的根本因素。③溶孔发育与构造角砾岩、构造裂缝发育具有强相关性。印支运动晚期，酸性流体沿破裂空间注入砂屑滩、藻纹层骨架等剩余孔隙发育区域形成次生溶孔；喜马拉雅运动早期，形成垂直裂缝和晚期构造角砾岩，发生晚期溶蚀作用及方解石脉体的充填；喜马拉雅运动晚期形成水平裂缝，进一步改善了储层物性。研究明确了川西中部雷口坡组白云岩储层的成岩序列及孔隙演化模式，提出“构造破裂-流体溶蚀-裂缝改造”三阶段的控储机制，为雷口坡组勘探生产提供地质依据。
Diagenesis of reservoirs affects pore development, distribution and reservoir quality. Relevant studies on the Middle Triassic Leikoupo Formation in central Western Sichuan Basin are still blank. In order to reveal the diagenetic evolution characteristics of dolomite reservoirs in the study area and their influence on reservoir quality, and to provide a theoretical basis for the exploration of carbonate oil and gas, the study on the dolomite diagenesis of Leikou Formation in western Sichuan Basin is systematically analyzed on the basis of data analysis such as core and thin section observations, dolomite order degree analysis, fluid inclusions and carbon-oxygen stable isotope tests. The results show that: (1) The Leikoupo Formation in central Western Sichuan mainly develops two different types of dolomite: micritic dolomite and micritic algal clast dolomite. The low degree of ordering and low formation temperature of the dolomite crystals indicate that they were formed by penecontemporaneous dolomitization. The reservoir spaces mainly consist of dissolved pores developed along algal frameworks, intergranular pores, and tectonic breccia interstices. (2) The dolomite in the study area has mainly undergone diagenetic processes such as fracturing, dolomitization, dedolomitization, dissolution, micritization, cementation, and surface-induced demineralization. Among them, structural fracture and dissolution play an improving role in the physical properties of the reservoir. Deep dissolution is the fundamental factor for the development of deep secondary pores. (3) The correlation between the development characteristics of dissolution pores and structural breccia and structural fractures is confirmed: acidic fluids were injected along the fracture space into the remaining pore development areas such as sandy shoal and the framework of the algal layer to form secondary dissolution pores in the late Indosinian stage. Vertical fissures and late structural breccia were formed in the early stage of the Himalayan Movement, and late dissolution and calcite vein filling occurred. Horizontal fractures formed in the late Himalayan period, further improving the physical properties of the reservoir. The research has for the first time clarified the diagenetic sequence and pore evolution model of the dolomite reservoir of the Leikoupo Formation in central Western Sichuan Basin, and proposes a three-stage reservoir control mechanism of "structural fracture-fluid dissolution-fracture modification", providing new geological basis for the exploration of the Leikoupo Formation.
成岩作用类型 / 成岩作用序列 / 孔隙演化 / 雷口坡组 / 川西中部
diagenetic types / diagenetic sequence / pore evolution / Leikoupo Formation / central Western Sichuan Basin
| [1] |
王廷栋, 郑永坚, 李绍基, 等. 从油气地化特征探讨川西北中坝雷三气藏的气源[J]. 天然气工业, 1989, 9(5): 20-26, 6.
|
| [2] |
李志高. 川西雷口坡组找油气前景[J]. 天然气工业, 1993(2): 28-33, 7.
|
| [3] |
王顺玉, 戴鸿鸣, 王廷栋, 等. 磨溪气田高成熟天然气的气源与运移[J]. 勘探家, 1998(2): 5-8.
|
| [4] |
沈安江, 周进高, 辛勇光, 等. 四川盆地雷口坡组白云岩储层类型及成因[J]. 海相油气地质, 2008, 13(4): 19-28.
Based on 1500 thin sections from 20 wells，It was found that two kinds of dolostone reservoirs of Triassic Leikoupo Fm. in Sichuan basin. Having undergone complicated diagenesis, the pore space in the reservoirs developed into residual primary intergranular and gypsum-dissolved pores at the early diagenetic stage. The substitution of arid and humid climate frequently controlled the reservoirs developed，which resulted in facies-selective distribution of reservoirs.
|
| [5] |
杨光, 石学文, 黄东, 等. 四川盆地龙岗气田雷四3亚段风化壳气藏特征及其主控因素[J]. 天然气工业, 2014, 34(9): 17-24.
|
| [6] |
甯濛, 刘殊, 龚文平. 川西坳陷三叠系雷口坡组顶部白云岩储层分布预测[J]. 中国石油勘探, 2015, 20(3): 30-37.
川西坳陷中三叠统雷口坡组顶部发育古风化壳型储层，近期PZ1井在该风化壳层再次获得高产工业气流，显示雷口坡组具有较大油气潜力，但TS1井的失利又显示了气藏的复杂性。川西坳陷雷口坡组顶部雷四上亚段具溶孔的颗粒白云岩是主要储层，优质储层以白云岩坪相为基础，后期发生白云岩化成岩改造。但由于断层及膏岩夹层的干扰，难以根据地震反射结构预测储层。研究发现，川西坳陷雷口坡组顶部表现出独特的断层相特征：坳陷内发育两个弧形小断层带，表现为强断裂变形白云岩相；断层带后方为断层不发育的完整背斜，表现为弱断裂变形白云岩相；坳陷东坡为揉皱膏岩相。利用这一特殊的断层相特征，依据地质力学原理，预测两弧形小断层带为刚性、单层厚度较薄的地层，为白云岩坪边缘相带，储层厚度较薄但裂缝发育；断层带后方完整地块为刚性、单层厚度较大的地层，为白云岩坪中心相带，储层厚度大；小断层带东侧的揉皱带为膏岩发育区。
The weathering crust reservoir developed on the top of Triassic Leikoupo Formation in Chuanxi depression. Recently, a high-yield industrial gas flow was acquired from Well PZ1 drilled at this weathering crust, indicating a great oil and gas potential of Leikoupo Formation, but the failure of Well TS1 also shows complexity of the gas reservoir. The grained dolomite with dissolved pores is the main reservoir in the 4th member of Leikoupo Formation in Chuanxi depression. Based on the dolomite flat, the high-quality reservoir came under dolomite diagenetic transformation in the later period. However, thanks to interferences of faults and gypsum in Leikoupo Formation, it is difficult to predict reservoirs by means of seismic reflection structure. The study indicates that the top of Leikoupo Formation in Chuanxi depression is characterized with unique fault facies. Two small arc-shaped fault belts developed in the depression, which are dolomite with strong fault deformation facies. The complete anticline with the faults undeveloped was behind the fault belt and in the form of dolomite with weak fault deformation facies. The eastern slope of the depression is crumpled gypsum facies. Based on the unique characteristics of fault and geo-mechanical principles, the two small arc-shaped fault belts are predicted as rigid formations with the single layers being thin and dolomite flat marginal facies. The layers of reservoir are relatively thin but with development of fractures. The complete block behind the fault belts is the rigid formation with the single layers being thick and dolomite flat central facies. Thickness of the reservoir is large. The crumpled zone east of the small fault belts is gypsum development zone.
|
| [7] |
李书兵, 许国明, 宋晓波. 川西龙门山前构造带彭州雷口坡组大型气田的形成条件[J]. 中国石油勘探, 2016, 21(3):74-82.
从2006年开始，经过8年的努力，实现了川西龙门山前构造带彭州雷口坡组天然气勘探重大发现，揭示了一个新的海相大气田——彭州气田。研究认为，彭州雷口坡组气藏特征表现为：具有大型正向隆起的构造背景，发育一套厚度大、分布广、纵向连续性较好、物性优、含气性好、产能高的白云岩溶蚀孔隙型储层，为常温常压、高含硫的酸性气田。总结出彭州雷口坡组大型气田的形成具备3个重要条件：一是多源供烃提供了丰富的物质基础，二是雷四段发育大规模白云岩孔隙型储层提供了充足的储集空间，三是大型正向隆起带提供了规模聚集场所。同时指出，龙门山前构造带雷口坡组气藏充满度高，勘探潜力大。
Through efforts in eight years since 2006, a great gas exploration discovery was made in the Pengzhou Leikoupo Formation of the Longmenshan piedmont tectonic belt, western Sichuan Basin, which contributed a new large marine gas field - Pengzhou gas field. Study indicates that the Pengzhou Leikoupo Formation reservoir presents as there is a dissolution-pore type dolomite reservoir under a structural setting of large positive uplift belt, with features of a big thickness, a wide distribution, better lateral continuities, good physical properties, high gas-bearing potentials, and high productivities. The reservoir is suggested as a sour gas field with normal temperature, normal pressure and high sulfur content. It is concluded that the Pengzhou large gas field of Leikoupo Formation was formed under three major conditions. First, multiple source rocks supplied abundant hydrocarbons, providing a good material basis. Second, large-scale dolomite pore type reservoir existed in the 4th member of the Leikoupo Formation, providing sufficient storage spaces. Third, large positive uplift belt provided enough spaces for hydrocarbon accumulation. Meanwhile, it is pointed out that the Leikoupo Formation gas reservoir in the Longmenshan piedmont tectonic belt features high filling degree and great exploration potential.
|
| [8] |
钱一雄, 武恒志, 周凌方, 等. 川西中三叠统雷口坡组三段—四段白云岩特征与成因:来自于岩相学及地球化学的约束[J]. 岩石学报, 2019, 35(4): 1161-1180.
|
| [9] |
孙春燕, 胡明毅, 胡忠贵, 等. 四川盆地中三叠统雷口坡组沉积特征及有利储集相带[J]. 石油与天然气地质, 2018, 39(3): 498-512.
|
| [10] |
宋晓波, 刘勇, 隆轲, 等. 四川盆地川西新场地区中三叠统雷口坡组气藏天然气来源[J]. 天然气地球科学, 2024, 35(12): 2121-2131.
It’s the first deep marine gas reservoir discovered in the Middle Triassic Leikoupo Formation in Xinchang area in the latest round of marine hydrocarbon exploration in the western Sichuan Basin. There has been controversy over the understanding of the gas source of this gas reservoir for years. Based on the geochemical data of natural gas from the latest round of drilling， combined with hydrocarbon conveyance conditions， the analysis of the origin and source of natural gas in the fourth member of Leikoupo Formation in Xinchang area was carried out. The research results indicate that there are differences in natural gas composition and hydrocarbon isotope characteristics of alkane gas between the upper and lower reservoir sections of the fourth member of Leikoupo Formation gas reservoir in Xinchang area， as well as different structural position. The higher H2S content may be related to its relatively strong TSR reaction in the lower reservoir section. The east part of the gas reservoir may have its source from continental or marine-continental coal type gas. The natural gas in the central and western of Xinchang area is mainly characterized by marine oil-type gas with relatively high maturity， corresponding to the development of relay remote source transport system， indicating that the natural gas mainly come from Permian source rocks， with partly coming from the Leikoupo Formation source rocks； While the natural gas in the northeast of Xinchang area is mainly mixed from marine and continental source gases， with relatively low maturity， corresponding to the development of the near source conveyance system of the orthogonal joint on the top of the Leikoupo Formation， indicating that the natural gas mainly comes from the source rocks of the Leikoupo Formation and Maantang-Xiaotangzi formations. |
| [11] |
李国蓉, 刘正中, 谢子潇, 等. 四川盆地西部雷口坡组非热液成因鞍形白云石的发现及意义[J]. 石油与天然气地质, 2020, 41(1): 164-176.
|
| [12] |
田瀚, 唐松, 张建勇, 等. 川西地区中三叠统雷口坡组储层特征及其形成条件[J]. 天然气地球科学, 2018, 29(11): 1585-1594.
近年来，四川盆地川西地区雷口坡组的油气勘探取得了丰富的成果，但是对雷口坡组碳酸盐岩储层特征及其控制因素的综合研究还相对薄弱，严重制约了雷口坡组进一步的油气勘探步伐。基于野外露头、岩心、测井等资料，结合实验分析数据，系统总结了川西地区雷口坡组储层的发育特征及其形成条件。研究表明：① 川西地区雷口坡组储集岩主要以藻白云岩、颗粒白云岩和细粉晶云岩为主，粒间孔、晶间孔和生物格架孔是主要的孔隙空间，储层整体表现为低孔低渗特征；②沉积相和岩溶作用共同控制着川西地区雷口坡组储层的发育，其中沉积相是储层发育的物质基础，准同生期的白云石化和岩溶作用是孔隙规模保持和次生孔隙形成的主控因素，而中三叠世末期的表生岩溶作用起到加强和巩固的作用，埋藏期有机酸的溶蚀作用起到保护作用。
In recent years，there are many oil and gas discoveries in Triassic Leikoupo Formation in western Sichuan Basin，but the comprehensive studies on the characteristics of carbonate reservoir and the controlling factors are weak，which has seriously restricted the oil and gas exploration and development.Based on field outcrop，core observations，rock sections，logging data and the experiment data，systematic summarizationof the characteristics and formation conditions of carbonate reservoir in Leikoupo Formation in western Sichuan Basin，it is concluded that:(1)the main types of reservoir rock in Leikoupo Formation are algal dolomite，grainstone dolomite and crystal dolostones，and the main pore space are intergranular pore，intercrystal pore and biological framework pore.The characteristics of reservoir are low porosity and low permeability.(2)The reservoir developments in Leikoupo Formation in western Sichuan Basin are controlled by sedimentary microfacies and karstification.The sedimentary microfacies provide the material foundation for the development of the reservoir.The dolomitization and karst effect in Penecontemporaneous period are the key factors to form and maintain pore space.The late hypergenensis at the end of middle Triassic can strengthen and consolidate the pore space.The dissolution of organic acid and the residual oil and gas play an active protective role.
|
| [13] |
王金琪. 安县构造运动[J]. 石油与天然气地质, 1990(3): 223-234.
|
| [14] |
全国地层委员会(中国地层表编委会). 中国地层表[R]. 中国地质调查局, 2012.
National Stratigraphic Committee (Editorial Committee of China Stratigraphic Table). Stratigraphic table of China[R]. China Geological Survey, 2012.
|
| [15] |
常远, 许长海,
|
| [16] |
方小敏. 青藏高原隆升阶段性[J]. 科技导报, 2017, 35(6): 41-50.
|
| [17] |
辛勇光, 周进高, 倪超, 等. 四川盆地中三叠世雷口坡期障壁型碳酸盐岩台地沉积特征及有利储集相带分布[J]. 海相油气地质, 2013, 18(2): 1-7.
Middle Triassic Leikoupo Formation is one of the important gas-bearing strata in Sichuan Basin. On the basis of comprehensive analysis of outcrops, drilled cores, laboratory, well logging and seismic data, it is shown that under control of palaeogeologic setting and eustatic fluctuations, Sichuan Basin was a water-shallow, high salty and wide barriored carbonate platform confined by palaeo-uplifts during Middle Triassic Leikoupo age. The platform was characterized basically by developing intrabasinal barriers, weak hydrodynamism, poor creature and arid climate. Leikoupo Formation beheaves an evolutional distribution of platform edge microfacies, lagoon microfacies, lagoon edge microfacies (platform interior shallow microfacies), microfacies, lagoon edge microfacies (platform interior shallow microfacies) to transitional microfacies successively from west to east in lateral and the evaporate rock, dolostone interbedded with limestone in longitudinal in the barriered platform. Some Middle Triassic Leikoupo lithofacies development and evolution maps are drawn. It is predicted that the favorable lithofacies for reservoirs develop in the peripheral regions of the barriors including the Longmen Shan Uplift in the west of the basin, and the Luzhou and Kaijiang Uplifts in the south and east of the basin.
|
| [18] |
|
| [19] |
何利, 刘建清, 隆轲, 等. 川西北地区中三叠统雷口坡组沉积相再认识[J]. 海相油气地质, 2023, 28(4): 371-380.
Based on the analysis of regional tectonic background,the understanding of tectonic-sedimentary characteristics and sedimentary facies evolution of Leikoupo Formation in northwestern Sichuan Basin has been deepened through drilling core observation,outcrop profile investigation,thin section identification,outcrop-well profile correlation and typical seismic profile interpretation.The results show that:(1)The uplift of the Xuefengshan ancient land during the Leikoupo period of the Middle Triassic intensified the geographical background of"low west,high east"in the Upper Yangtze sea.With the continuous uplifting of the Luzhou palaeohigh and Kaijiang palaeohigh,the subsidence center and depocenter during the Leikoupo period was formed in Jiangyou-Mianzhu area of northwestern Sichuan Basin,and in Late Triassic the depression extended southward to the Kuahongdong area of Emei County.(2)Controlled by the geographical background and sea level change,three major sedimentary facies,i.e.,platform margin facies,limited platform facies,and evaporite platform facies,are developed from west to east in Leikoupo Formation.Shoal subfacies is developed in the platform margin facies,which mainly consists of sandy shoal and oolitic shoal microfacies.The limited platform facies consists of shoal,tidal flat and lagoon subfacies,including sandy shoal,algae limestone flat,calcareous dolomite flat,tidal channel,desalinated lagoon,saline lagoon,brackish lagoon,and other microfacies.The evaporite platform facies is composed of evaporite flat and salt lake subfacies,with microfacies of gypsum flat,gypsum-dolomite flat,dolomite-gypsum flat,dolomite flat,gypsum-salt lake and halite lake developed in them.(3)The platform margin shoal has a significant scale with densely packed internal clastic and oolitic grains.Conversely,the internal shoal has a smaller scale primarily characterized by algae debris particles.We propose a sedimentary model of"platform margin facies-limited platform facies-evaporite platform facies"in the Leikoupo Formation,and the sedimentary changes are controlled by the sedimentary base tilting northwest and the transgression-regression cycle of the sea level.
|
| [20] |
冯增昭. 沉积岩石学[M]. 北京: 石油工业出版社, 1982.
|
| [21] |
徐开礼, 朱志澄. 构造地质学[M]. 北京: 地质出版社, 1987.
|
| [22] |
杨成. 川西坳陷雷口坡组油气成藏条件研究[D]. 成都: 成都理工大学, 2015.
|
| [23] |
吉小强. 川西坳陷雷口坡组气源及成藏特征[D]. 成都: 西南石油大学, 2017.
|
| [24] |
|
| [25] |
|
| [26] |
刘建清, 赖兴运, 于炳松, 等. 地层水条件下碳酸盐矿物热力学平衡条件及其在克拉2气田的应用[J]. 沉积学报, 2006, 24(5): 636-640.
|
| [27] |
|
| [28] |
万友利, 赵瞻, 胡志中, 等. 羌塘盆地中侏罗统布曲组白云岩有序度与晶胞参数的影响因素及地质意义[J]. 沉积与特提斯地质, 2021, 41(4): 512-523.
|
| [29] |
|
| [30] |
|
| [31] |
余金诚. 川西南地区雷口坡组沉积相特征与储层评价研究[D]. 成都: 西南石油大学, 2016.
|
| [32] |
揭君晓. 川西坳陷中段中三叠统雷口坡组碳酸盐岩油气储层特征研究[D]. 贵阳: 贵州大学, 2008.
|
| [33] |
朱光有, 张水昌, 梁英波, 等. 川东北地区飞仙关组高含H2S天然气TSR成因的同位素证据[J]. 中国科学(地球科学), 2005, 35(1): 1037-1046.
|
| [34] |
朱光有, 张水昌, 梁英波, 等. 川东北飞仙关组高含H2S气藏特征与TSR对烃类的消耗作用[J]. 沉积学报, 2006, 24(2): 300-308.
|
/
| 〈 |
|
〉 |
