为了指导四川盆地下一步的天然气勘探部署，系统总结了“十三五”以来该盆地风险勘探领域的关键理论认识、技术进展与重大成果。以中国石油西南油气田公司勘探实践为对象，探究了海相常规气、陆相致密气、页岩气及煤岩气4大领域的天然气成藏地质条件，分析了地球物理与工程技术协同创新成效，明确了构造—沉积演化对大型控藏地质单元的控制作用。研究结果表明：①海相常规气领域，深化了“四古”（古裂陷槽、古台地、古油裂解气、古隆起）成藏理论与“槽—台分异”新认识，创新了斜坡区“断层—岩性控圈、立体成藏”模式，开辟了蓬莱、川西南、川西北等5个超1 000×10⁸m³规模天然气增储区，新增探明地质储量超1.27×10¹²m³；②陆相致密气领域，基于全油气系统理论实现由隆起区岩性气藏向坳陷区源内致密气藏的战略转移，川西北三叠系须家河组新增天然气地质储量1 110×10⁸m³，展现3.04×10¹²m³资源前景；③页岩气领域，建立了寒武系筇竹寺组“槽—隆”时空耦合控富集模式与二叠系吴家坪组“四高”优质页岩评价体系，开辟两个1.00×10¹²m³级资源的勘探新层系；④煤岩气领域，揭示了深层二叠系龙潭组“高压、高含气、高游离气”的“二元”赋存新机制，实现战略新发现，预测有利区面积1.04×10⁴km²。结论认为，持续围绕大型控藏地质单元强化基础地质研究、发展高分辨率地震成像与隐蔽圈闭识别技术、提升超深储层改造与深层页岩气压裂工艺适应性，是保障四川盆地天然气储量与产量持续增长的关键路径。

To guide the future deployment of natural gas exploration in the Sichuan Basin, this paper systematically summarized the critical theoretical understandings, technical progress and significant achievements with respect to risk exploration in the basin since the 13^th Five-Year Plan began. Based on the exploration practices of PetroChina Southwest Oil&Gasfield Company, the geological conditions for gas accumulation were investigated in four major domains (marine conventional gas, continental tight gas, shale gas, and coal-rock gas), the collaborative innovations in geophysical and engineering technologies were analyzed, and the controls of tectono-sedimentary evolution on large-scale reservoir-controlling geological units were clarified. The following results are obtained. (i) In terms of marine conventional gas, the “four-paleo” accumulation theory (paleo-rift trough, paleo-platform, paleo-oil cracking gas, and paleo-uplift) and the new insights on trough-platform differentiation were deepened, and an innovative model of “three-dimensional hydrocarbon accumulation in traps controlled by faults and lithologies” was established for slope zones, supporting the identification of five new areas such as Penglai, southwestern Sichuan Basin, and northwestern Sichuan Basin, each with reserves exceeding 1 000×10⁸ m³, contributing the addition of proven gas in place (GIP) over 1.27×10¹² m³. (ii) In terms of continental tight gas, a strategic shift from lithologic gas reservoirs in uplift areas to inner-source tight gas reservoirs in depression areas was achieved in accordance with the theory of whole petroleum system, with newly added GIP of 1 110×10⁸ m³ in the Triassic Xujiahe Formation, northwestern Sichuan Basin, suggesting a resource potential up to 3.04×10¹² m³. (iii) In terms of shale gas, the enrichment model controlled by the trough-uplift spatiotemporal coupling for the Cambrian Qiongzhusi Formation and the “four-high” (high TOC, high brittle mineral, high porosity, and high gas content) quality shale evaluation system for the Permian Wujiaping Formation were established, and two 1.00×10¹² m³-scale strata were defined for exploration. (iv) In terms of coal-rock gas, a new “dual” occurrence mechanism for deep Permian Longtan Formation featured with high pressure, high gas saturation and high free gas content was revealed, leading to a novel strategic discovery with the favorable area predicted to be 1.04×10⁴ km². It is concluded that the continuous growth of natural gas reserves and production in the Sichuan Basin will be primarily secured by enhancing the basic research on large-scale reservoir-controlling geological units, developing high-resolution seismic imaging and subtle trap identification technologies, and improving the adaptability of ultra-deep reservoir stimulation and deep shale gas reservoir fracturing processes.

基于野外、钻井和地震资料分析,恢复四川盆地德阳—安岳侵蚀裂陷槽形成演化过程,并对勘探领域进行划分和评价。结果表明：①德阳—安岳侵蚀裂陷槽及周缘震旦系灯影组沉积特征具有明显差异。侵蚀裂陷槽北段灯影组发育深水沉积,盆地北部灯影组发育盆地—斜坡—台地边缘—局限台地沉积模式,中—南段灯影组为碳酸盐台地沉积环境。②德阳—安岳侵蚀裂陷槽是伸展裂陷和岩溶侵蚀作用叠加改造而成,侵蚀裂陷槽北段以拉张裂陷作用为主,中段和南段为桐湾多幕次侵蚀作用改造而成。基于侵蚀裂陷槽分段性成因,将其及周缘灯影组划分为盆地北部台缘岩性丘滩体、中部台内岩溶丘滩体和中—南部槽内岩溶残丘3大勘探领域,其中盆地中—南部槽内岩溶残丘是盆地天然气勘探战略突破新领域,北部台缘岩性丘滩体是盆地天然气万亿立方米资源增储新阵地。

利用钻井和地震资料,在上扬子克拉通德阳-安岳地区发现晚震旦世-早寒武世克拉通内裂陷,受张性断裂控制,呈NNW向展布,南北长320 km、东西宽50~300 km。裂陷演化经历了形成期、发展期、消亡期3个阶段,形成有利的近源成藏组合。研究结果表明:1晚震旦世灯影组沉积期为裂陷形成期,裂陷内发育槽盆相沉积,两侧发育台地边缘相丘滩体,控制了灯影组优质储层的形成与分布;2早寒武世梅树村组沉积期-筇竹寺组沉积期为裂陷发展期,充填500~1000 m的深水陆棚相泥质岩,是优质烃源岩沉积期;3沧浪铺组沉积期为裂陷消亡期,经填平补齐,结束了克拉通内裂陷的演化历史。克拉通内裂陷是安岳特大型气田形成的关键因素,裂陷内优质烃源岩为特大型气田提供了充足的气源,在晚燕山期-喜马拉雅期川中古隆起西部快速隆升过程中形成区域性侧向封堵,有利于裂陷东翼的高石梯-磨溪地区特大型气田的保存。克拉通内裂陷及其大气田成藏作用对古老克拉通盆地深层油气勘探有重要的参考价值。

According to the drilling and seismic data,the Late Sinian-Early Cambrian intra-cratonic rift was found in Deyang-Anyue area of the Upper Yangtze craton.This rift is controlled by tensional fault and distributed in NNW trending with the NS length of 320 km and EW width of 50-300 km.After three stages of rift evolution,i.e.,the forming stage,developing stage and dying stage,a favorable near-source accumulation assemblage was formed.The research results indicate that:(1) the sedimentary stage of Late Sinian Dengying Formation is the rift forming stage,during which trough-basin facies sedimentation is developed in the rift,while platform marginal facies mounds and shoals are developed on both side,controlling the formation and distribution of high-quality reservoirs in Dengying Formation;(2) the sedimentation stage of Early Cambrian Meishucun-Qiongzhusi Formation is the rift development stage,during which deep-water continental shelf facies argillaceous rocks are filled in the rift with a thickness of 500-1000 m,indicating the sedimentation stage of high-quality source rocks;(3) the sedimentation stage of Canglangpu Formation is the rift dying stage,terminating the evolution history of intra-cratonic rift by gap filling.The intra-cratonic rift is a key factor for the formation of Anyue giant gas field,where the high-quality source rocks provide abundant gases for the giant gas field.A regional lateral sealing occurred during the rapid rising of the western paleo-uplift in Central Sichuan during the Late Yanshan-Himalayan period,favorable to the preservation of the Gaoshiti-Moxi giant gas field on the east wing of the rift.The intra-cratonic rift and its role in giant gas accumulation provides a significant reference for deep oil and gas exploration in paleo-craton basins.

基于钻测井、地震和露头资料,从沉积、构造和岩溶作用的角度分析了四川盆地震旦纪末期—寒武纪早期台盆的形成与演化过程,利用灯影组三段+灯影组四段的残余厚度、麦地坪组+筇竹寺组的厚度及麦地坪组的岩相分区特点综合确定了台盆的展布,并揭示其对灯影组天然气分布的控制作用。台盆区表现为灯影组三段+灯影组四段残厚小、上覆充填的麦地坪组与筇竹寺组厚度大、麦地坪组以深水相的含磷碳硅泥岩为主,平面上主要分布于青川—资阳—宜宾一带,其形成和演化经历了4个阶段:1灯影组一段、灯影组二段沉积期,四川盆地为一镶边碳酸盐台地,台地边缘和台地内部丘滩体发育,灯影组二段、灯影组三段之间的桐湾运动一幕作用形成了川西海盆的雏形,台盆与其两侧地貌存在差异;2灯影组三段沉积期,上扬子内克拉通由于拉张裂陷,形成了以磨溪、长宁、镇雄等为沉积中心的沉降带,控制着优质烃源岩的分布;灯影组四段沉积期,四川盆地演化为一内部发育台盆的镶边碳酸盐台地,灯影组末期的桐湾运动二幕作用使得四川盆地整体抬升遭受暴露,高部位风化剥蚀、低部位 流体下切侵蚀,并使台盆区的范围达到最大;3寒武纪早期的麦地坪组为灯影组岩溶地貌基础上的第一套充填沉积,且平面上发育3个岩相区,麦地坪组与筇竹寺组之间的桐湾运动三幕作用对麦地坪组沉积后的地貌进行了局部改造;4筇竹寺组与沧浪铺组的持续充填,使四川盆地演化为一较平缓的碎屑岩缓坡。台盆的形成与演化不仅促进了其周缘灯影组四段台缘带优质储层的形成,而且控制着寒武系麦地坪组与筇竹寺组2套优质烃源岩的分布,环台盆灯影组白云岩具有良好的源-储配置关系,是最有利的勘探领域。

Based on the analysis of welling, logging, seismic information and outcrops, the formation and evolution of Upper Sinian to Lower Cambrian intraplatformal basin (IPB) in Sichuan Basin was studied from the aspects of sedimentation, tectonics and karstification, and its distribution was defined by using total residual thickness of the 3rd and 4th member of Dengying Formation (DYF), total thickness of Maidiping Formation (MDPF) and Qiongzhusi Formation (QZSF), and lithofacies features, and its control on natural gas distribution of DYF was revealed. Its typical characteristics were small total residual thickness of the 3rd and 4th member of DYF, large total thickness of MDPF and QZSF, and developing mudstone containing phosphates and silicon. It underwent 4 stages: (1) During the 1st and 2nd member of DYF, Sichuan Basin was a rimmed platform with mounds and shoals developed in platform margin and interior. The first episode of Tongwan taphrogenesis between the 2nd and 3rd member of Dengying Formation formed the embryonic form of the IPB in western Sichuan Basin. And there exited landform difference between the IPB and its two sides. (2) During the 3rd member of DYF, Upper Yangzi craton extended and a subsidence zone was formed with Moxi, Changning and Zhengxiong area as its depositional centers, controlling the distribution of favored hydrocarbon source rocks. During the 4th member of DYF, Sichuan Basin evolved into a rimmed platform with an IPB. The second episode of Tongwan taphrogenesis after DYF made Sichuan Basin rise as a whole characterized by weather denudation in high position and fluid erosion in low part, and Qingchuan-Ziyang-Yibin IPB was shaped. (3) MDPF of Lower Cambrian was the first sediment on karst landform of DYF, with 3 lithology zones in plane distribution, and the third episode of Tongwan taphrogenesis reformed the depositional landform locally. (4) After lasting filling of QZSF and Canglangpu Formation, Sichuan Basin evolved into a siliclastic ramp. The formation and evolution of the IPB did not only promote the formation of high quality platform-margin dolomite reservoirs of the 4th member of DYF, but also control the distribution of two high quality hydrocarbon source rocks of MDPF and QZSF. The surrounding areas of the IPB were favorable petroleum exploration areas, with good contact configuration relationships between Cambrian hydrocarbon source rocks and dolomite reservoir of DYF.

基于沉积、构造综合分析，利用露头、钻井、测井及地震资料，研究四川盆地震旦系威远—安岳拉张侵蚀槽的平面、剖面特征，并根据地层、岩性、构造及区域演化等特征对震旦系进行剥蚀恢复，再现桐湾运动时期拉张侵蚀槽各阶段发育演化及其改造过程。威远—安岳拉张侵蚀槽沿蓬莱—安岳—荣昌一线呈北西向展布，具有东陡西缓的特征。研究横跨拉张侵蚀槽中部的威远—龙女寺地震剖面发现，威远—安岳拉张侵蚀槽是震旦纪期间基底断裂多幕堑垒式活动导致灯影组地层差异抬升、差异侵蚀和差异溶蚀等多种地质过程综合作用的结果，其形成可分为早、中、晚3个阶段。通过剖面剥蚀恢复，定量测算了拉张侵蚀槽侵蚀、溶蚀量，最大可达600 m。图11参28

Based on comprehensive analysis of deposition and structure, the horizontal and vertical characteristics of the Weiyuan-Anyue extension-erosion groove have been studied by outcrop, drilling, well logging and seismic data. According to the strata, lithology, structure and regional evolution, Sinian system before the erosion has been reconstructed to show the development and transformation of the erosion-extension groove in the Tongwan movement. The Weiyuan-Anyue extension-erosion groove is distributed along the Penglai-Anyue-Rongchang in NW direction, with the east area steeper than the west in groove. According to the study of the Weiyuan-Longnüsi seismic profile across the middle area of extension-erosion groove, the formation of the Weiyuan-Anyue extension-erosion groove is the synthetic result of different geological processes from differential uplift, differential erosion and dissolution in the Dengying Formation caused by the multiple-phase episode grabon or horst movement of the basement fault in Sinian. The formation of the Weiyuan-Anyue extension-erosion groove can be divided into three stages, and the erosion and dissolution can be calculated quantitatively by denudation recovery profile, its maximum can reach 600 m.

中国石油天然气股份有限公司（以下简称“中国石油”）“十二五”油气勘探面对“更老、更深、更复杂”等诸多挑战，大力实施资源战略，强力推进地质认识创新与工程技术攻关。海相碳酸盐岩“四古控藏”、碎屑岩岩性地层大面积成藏、前陆冲断带“四位一体”超深层高效成藏、页岩气与致密油等非常规油气成藏等地质新认识创新发展；宽频、宽方位、高密度地震采集、处理和解释一体化技术、复杂储层测井评价与流体识别技术、超深层安全快速钻井技术、水平井体积压裂等工程新技术蓬勃发展。“十二五”期间，中国石油形成了15 个油气规模储量区，探明石油地质储量连续10 年超6×10⁸t，探明天然气地质储量连续9 年超4000×10⁸m³，成为中国石油历史上持续时间最长、总量最高的高峰期。“十三五”期间，面临低油价、“新两法”实施等外部环境变化新形势和勘探开发对象日趋复杂、资源品位变差等诸多内部挑战，研究认为：中国石油处于勘探中期阶段，油气领域科技创新正处于“加速发展期”。通过继续实施资源战略，以海相碳酸盐岩、致密气、前陆冲断带三大领域为天然气重点勘探领域，以碎屑岩岩性地层为石油勘探主体，坚持理论、技术、管理创新，“十三五”将不断发现优质高效规模储量，保持油气储量持续高峰增长。

Faced with various challenges involved in older, deeper and more complicated oil and gas exploration targets, PetroChina Company Limited (“PetroChina”) vigorously implemented resource strategies and promoted geologic cognition and innovation and engineering technology research during the 12^th Five-Year Plan. New geologic cognitions were innovatively obtained, such as “four-palaeos” (i.e. paleorift, paleo-bioherm beach complex, paleo-trap, and paleo-uplift) controlling the formation of marine carbonate reservoirs, extensive formation of clastics lithologic reservoirs, high-efficient formation of ultra-deep reservoirs in “four-in-one”foreland thrust belts (namely the belts with folded source rock, ultra-deep effective reservoir, very thick gypsum-salt rock, and imbricate structure), and formation of unconventional oil/gas (e.g. shale gas and tight oil) reservoirs. A series of new engineering technologies were developed, including integrated wide-azimuth, broadband and high-density seismic acquisition, processing and interpretation technology, logging evaluation and fluid identification technology for complex reservoirs, safe and fast drilling technology for ultra-deep layers, and horizontal-well volume fracturing technology. During the 12^th Five-Year Plan, 15 large-scale oil and gas reserve zones were discovered, contributing to the performance with proved original oil in place (OOIP) over 6×10⁸t for 10 consecutive years and proved original gas in place (OGIP) over 4000×10⁸m³ for 9 consecutive years. It records the peak period with the longest duration and the highest total production in the history of PetroChina. During the 13^th Five-Year Plan, PetroChina will encounter new situations with changed external environment (e.g. low oil price, and launching of the latest versions of Production Safety Law and Environmental Protection Law) and many internal challenges (e.g. increasing complexity of targets and deterioration of resource quality) in exploration and development. The study indicates that, PetroChina is at the middle stage of exploration and its oil and gas technical innovation is in the period of speeding-up development. During the 13th Five-Year Plan, PetroChina will continue the resource strategies and persist in theoretical, technical and managerial innovation with marine carbonate rocks, tight gas and foreland thrust belts as the key natural gas exploration domains and clastics lithologic formations as the major oil exploration targets. In this way, PetroChina will devote to discover large-scale reserves with high efficiency and quality, in order to increase oil and gas reserves continuously at peak.

针对川中蓬莱气区震旦系—二叠系气藏气水关系复杂、天然气分布规律不清、勘探拓展难度大等问题，基于气藏解剖、天然气地球化学分析、储层测试、测井-地震资料分析及盆地模拟与动力学分析，开展天然气来源、充注过程以及富集规律等研究。结果表明：①三叠系嘉陵江组盐下发育4套高效烃源岩，以寒武系烃源岩为主；储层非均质性强、6套有效储集体相互分隔但动态连通，多期走滑断裂相关的断-缝-洞-面构成油气输导网络。②寒武系烃源岩生烃增压产生的高过剩压力造成超压，驱动源灶上下双向排烃，古油藏裂解气、烃源岩内残留烃裂解气等多元供烃；震旦系—二叠系经历多期次动态成藏过程，在多层系非均质储层中形成大面积“甜点”式气藏，经晚期调整至今定型。③建立“多元供烃、立体输导、多期运聚、动态调整、岩性控藏”的深层海相天然气立体成藏模式，提出具正向构造背景的规模储集体、晚期构造稳定区、斜坡构造区等天然气勘探有利区带。

综合利用野外露头、钻井岩心分析、测录井及地震剖面等资料，对四川盆地及周缘寒武系沧浪铺组沉积充填过程开展了系统研究。研究结果表明：①四川盆地寒武系沧一段的沉积构造格局整体表现为“一隆、四洼、两高带”，岩性以碳酸盐岩为主；沧二段地层厚度差异性较小，区域地貌趋于均一，岩性以碎屑岩为主。②研究区寒武系沧一段沉积时期，平面上具有东西分异的沉积特征，主要受德阳—安岳古裂陷槽隔挡作用影响。裂陷槽西侧靠近物源区，主要发育混积潮坪沉积，裂陷槽东侧则广泛发育清水碳酸盐岩沉积；沧二段沉积时期，因裂陷槽隔挡作用减弱，全盆陆源碎屑沉积大幅增加，整体上以碎屑岩浅水陆棚沉积为主。③研究区寒武系沧一段优质白云岩储层以残余鲕粒云岩、砂屑云岩和粉晶云岩为主，宏观上颗粒滩的分布主要受到水下低隆和台洼边缘相对高部位控制，微观上储集空间主要受白云石化作用及溶蚀改造作用控制，发育粒内溶孔、粒间溶孔、晶间溶孔和晶间孔等孔隙类型，紧邻下伏筇竹寺组优质烃源岩，具有近源充注成藏的天然优势。

Based on outcrops，drilling cores，logging and seismic data，the sedimentary filling process of Cambrian Canglangpu Formation in Sichuan Basin and adjacent areas were studied. The results show that：（1）The overall sedimentary structural pattern of the first member of Cambrian Canglangpu Formation（Cang-1 member） in Sichuan Basin presents “one uplift，four depressions，and two high zones” characteristics，with carbonate rocks as the main lithology. The second member of Canglangpu Formation（Cang-2 member）is gradually filled in，and the regional paleogeomorphology tend to be uniform，with clastic rocks being the main lithology. （2）During the sedimentary period of Cang-1 member in the study area，the barrier effects of Deyang-Anyue ancient rift trough led to an east-west differentiation sedimentary pattern in the plane. The western trough which is near the provenance，mainly developed mixed tidal flat deposits，while the eastern trough mainly developed carbonate deposits. During the sedimentary period of Cang-2 member，the barrier effects of trough was weakened，and the terrigenous debris significantly increased in the whole basin that were characterized by clastic rock shallow shelf deposits.（3）The high-quality dolomite reservoirs of Cang-1 member in the study area are mainly composed of residual oolitic dolomite，sandstone dolomite，and powder crystal dolomite. Macroscopically，the distribution of shoals is mainly controlled by underwater low uplift and relatively high parts of the platform depression edge. Microscopically，the reservoir space is mainly controlled by dolomitization and dissolution transformation，with intragranular dissolved pores，intergranular dissolved pores，and intercrystalline dissolved pores developed. It is adjacent to the high-quality source rocks of the underlying Qiongzhusi Formation and has an advantage of near-source filling and accumulation.

The Ediacaran Dengying Formation 2nd Member (hereafter 2nd Member) in the Sichuan Basin is influenced by major tectonic events including the Caledonian, Indosinian, and Himalayan orogenies and this strata has experienced a complex hydrocarbon accumulation history, resulting in inconsistent gas–water contacts. To elucidate this complex history, this study investigates the diagenetic mineral filling sequence within the Dengying 2nd Member in the Penglai area. We integrated data from analytical techniques such as cathodoluminescence (CL), in situ trace element analysis, U–Pb geochronology, and fluid-inclusion microthermometry. Based on these analyses, this study established the paragenetic sequence, incorporating both diagenesis and hydrocarbon accumulation, for the Dengying 2nd Member. This sequence comprises eight distinct phases of mineral precipitation and hydrocarbon emplacement: fibrous dolomite, granular dolomite, fine crystalline dolomite, first-phase bitumen, medium crystalline dolomite, saddle dolomite, second-phase bitumen, and quartz. From this sequence, we propose a four-stage hydrocarbon accumulation model for the Dengying Formation: (1) primary migration and accumulation during the Indosinian period; (2) oil cracking to gas during the Yanshanian period; and (3) and (4) two distinct stages of gas pool adjustment during the Himalayan period. Corresponding to these stages, this study developed distinct accumulation models and simulated migration and accumulation processes during key stages. The results indicate that the distribution of paleo-oil pools exerts significant control over the location of present-day gas accumulations. Initial oil charge was controlled by the distribution of carrier beds and hydrocarbon charging pathways, with water zones observed more frequently in the lower intervals of the Dengying 2nd Member. Subsequently, gas generated from oil-cracking filled these carrier beds, with areas of gas enrichment correlating with zones of high paleo-oil saturation. Finally, during the later adjustment stages, fault activity induced gas remigration and leakage, significantly impacting the final trapping configuration and preservation of gas accumulations.

川西地区近期部分井的油气勘探发现显示，龙门山地区中泥盆统观雾山组发育展布良好的白云岩储层，但受龙门山断裂带推覆影响，观雾山组地层展布特征仍然认识不清、岩相古地理研究仍处于定性分析阶段。为厘清川西龙门山地区中泥盆统观雾山组岩相古地理特征：首先，基于平衡剖面技术定量恢复了龙门山断裂带北、中、南3段的剖面，建立起野外露头点现今位置与初始位置之间的函数关系，恢复了露头点的推覆距离，认为龙门山断裂带总体推覆距离约40 km，地层展布恢复后，观雾山组在彭灌古岛与都江堰之间存在一个沉降中心，观雾山组整体呈西厚东薄、南厚北薄的分布趋势；其次，以恢复后的观雾山组地层展布为基础，通过野外实测、岩心及测井资料综合分析，重建了龙门山地区观雾山组岩相古地理特征。研究发现，龙门山地区中泥盆统观雾山组岩石类型以白云岩（粉晶-细晶白云岩、砾屑-角砾白云岩、生屑白云岩和生物白云岩）为主，局部发育灰岩（泥晶灰岩、生屑灰岩和生物灰岩）及少量的碎屑岩与碳酸盐岩混合沉积；识别出台地边缘礁滩相、开阔台地相和局限台地相3种主要的沉积相类型；台地边缘礁滩相分布于桂溪—大木垭地区，开阔台地发育在K2井、擂鼓镇、龙王庙一带，局限台地位于彭灌古岛—宝兴古岛以东至上扬子古陆之间的地区；随着海平面上升，台地边缘礁滩相呈现出向东迁移的趋势。

Through the recent oil-gas exploration of some wells in the western Sichuan area, it is found that the dolomite reservoirs with favorable distribution are developed in the Middle Devonian Guanwushan Formation of Longmenshan area. But due to the nappe impact from Longmenshan Fault Belt, the distribution characteristics of Guanwushan Formation are still obscure, and the study on lithofacies paleo-geography is still in a stage of qualitative analysis. To clarify the lithofacies paleo-geographic characteristics of the Middle Devonian Guanwushan Formation in Longmenshan area of the western Sichcuan, the following two steps have been conducted:(1) The three profiles, i.e., the north profile, the central profile and the south profile, of Longmenshan Fault Belt are quantitatively restored based on the balanced section technique, so as to create the function relationship between current location and initial location of field outcrop point and restore the nappe distance of outcrop point. It is considered that the total nappe distance of Longmenshan Fault belt is about 40 km, and after the restoration of stratigraphic distribution, there is a subsidence center between Pengguan Paleo-island and Dujiangyan of the Guanwushan Formation. On the whole, Guanwushan Formation tends to be thicker in the west while thinner in the east and thicker in the south while thinner in the north. (2) Based on the stratigraphic distribution of Guanwushan Formation after restoration, the lithofacies paleo-geographic characteristics of Guanwushan Formation in Longmenshan area are reconstructed by field measurement and comprehensive analysis on core and well-logging data. Meanwhile, the study shows that the rock types of the Middle Devonian Guanwushan Formation in Longmenshan area are dominated by dolomite (silty crystal-fine grain dolomite, gravel-brecciated dolomite, bioclastic dolomite and biogenic dolomite); in local area are developed limestone (micrite, bioclastic limestone and biogenic limestone) and a small amount of mixed sediments consisting of clastic rocks and carbonate rocks. Three main sedimentary facies types are identified, including platform-margin reef flat facies, open platform facies and restricted platform facies. The platform-margin reef flat facies is distributed in Guixi-Damuya area, the open platform is developed in Well K2-Leigu Town-Longwangmiao, while the restricted platform is located in the areas between the east of Pengguan Paloe-island-Baoxing Paleo-island and the Upper-Yangtze Paleo-land. As the sea level rising, the platform-margin reef flat facies shows the tendency of eastward migration.

为了揭示四川盆地海相克拉通阶段构造—沉积演化规律，明确古裂陷和古隆起对规模储集相带发育的控制作用，基于二维和三维地震资料、盆缘野外露头、盆内钻井与录井资料，系统开展了构造—沉积演化综合研究。研究结果表明：①四川盆地海相地层主要经历了兴凯、加里东、海西、印支4期构造旋回，形成“隆凹相间”的构造—沉积格局。②在拉张构造背景下，桐湾期盆地形成德阳—安岳裂陷和城口—石柱裂陷，控制了裂陷槽边缘丘滩体的连片分布；海西期盆地形成开江—梁平海槽、城口—鄂西海槽及蓬溪—武胜浅水陆棚，控制了边缘带二叠系、三叠系礁滩相沉积的大面积发育。③在挤压构造背景下，加里东期盆地形成川中古隆起，控制了环古隆起寒武系、奥陶系多期滩体的规模发育；印支期盆地形成泸州—开江古隆起，控制了三叠系下统嘉陵江组、三叠系中统雷口坡组滩相沉积的展布格局。结论认为，古裂陷与古隆起边缘坡折带控制了高能丘滩体的规模展布，是孔隙型储层发育的基础，具有巨大的油气勘探潜力，未来仍是四川盆地海相克拉通地层天然气勘探的重点领域。

To identify the tectono-sedimentary evolution pattern of the Sichuan Basin in the marine craton stage and clarify the controls of paleo-rifts and paleo-uplifts on the development of large-scale reservoir facies zones, a systematic study of the tectono-sedimentary evolution was conducted based on 2D and 3D seismic data, field outcrops at the basin margin, and drilling and logging data of the basin. The following results are obtained. (i) The marine strata in the Sichuan Basin mainly experienced four periods of tectonic cycles: Xingkai, Caledonian, Hercynian, and Indosinian, forming a tectono-sedimentary pattern characterized by alternating uplifts and depressions. (ii) Under the extensional tectonic setting, during the Tongwan period, the Deyang-Anyue and Chengkou-Shizhu rifts were formed in the basin, which controlled the distribution of contiguous mound-shoal complexes along rift trough margins; during the Hercynian period, the Kaijiang-Liangping trough, the Chengkou-Western Hubei trough, and the Pengxi-Wusheng shallow water shelf were formed, controlling the widespread development of the Permian and Triassic reef-shoal deposits in marginal zones. (iii) Under the compressional tectonic setting, the central Sichuan paleo-uplift was shaped during the Caledonian period, dominating the large-scale development of multi-stage Cambrian and Ordovician shoal bodies around the paleo-uplift; during the Indosinian period, the Luzhou-Kaijiang paleo-uplift was formed, controlling the distribution of shoal-facies sedimentation in the Lower Triassic Jialingjiang Formation and the Middle Triassic Leikoupo Formation. It is concluded that the slope-break zones along the margins of paleo-rifts and paleo-uplifts control the large-scale distribution of high-energy mound-shoal complexes, laying the foundation for the development of porous reservoirs. These highly potential zones remain the key targets for future gas exploration in marine cratonic strata of the Sichuan Basin.

绵阳—广安浅水陆棚是继开江—梁平海槽后,四川盆地在二叠系—三叠系开展天然气勘探的又一个重点区域,目前的勘探主要聚焦于其两侧的遂宁—广安生屑滩发育区,而对陆棚内部集群发育的生物礁未给予足够关注。部署于陆棚内的蓬深10井于2023年在二叠系长兴组试气,取得了206.36×10⁴m³/d的高产工业气流,展示了绵阳—广安浅水陆棚生物礁领域具有巨大的油气勘探前景。基于岩心样品、固体沥青样品以及地震-测井资料,通过岩石学和地球化学分析,对蓬深10井长兴组的地层和沉积特征、油气成藏条件、油气成藏期次和成藏模式进行了系统研究。研究成果表明:1蓬深10井长兴组发育浅水陆棚相塔礁亚相沉积,礁体储层发育大量溶孔和裂缝,与上覆的飞仙关组泥岩形成了良好的储-盖组合。②储层内固体沥青的地球化学特征表明天然气具有来自二叠系龙潭组和寒武系筇竹寺组烃源岩的贡献,蓬深10井区发育了贯穿震旦系灯影组与二叠系长兴组的深大走滑断裂,是油气垂向输导的关键通道;蓬深10井长兴组圈闭主要为岩性封闭,构造运动对圈闭有效性的影响较小。③包裹体均一温度与储层埋藏史-热演化史揭示,油气充注主要发生在早三叠世、中侏罗世和晚侏罗世,结合油气充注时期的断裂及圈闭发育情况,最终建立了多源供烃、断裂沟通、构造-岩性圈闭内聚集调整的油气成藏模式。蓬深10井的勘探突破揭示该井为浅水陆棚生物礁领域有效规模成藏的代表,为四川盆地二叠系—三叠系礁滩领域天然气的勘探部署指明了新方向。

The Mianyang-Guang’an shallow-water shelf is another key area for Permian-Triassic natural gas exploration in Sichuan Basin, following the Kaijiang-Liangping trough. Currently, existing efforts mainly focus on hydrocarbon exploration in bioclastic bank development zones at the margin of Suining and Guang’an platforms on both sides of the study area, while insufficient attention has been paid to the clustered biological reefs within the shelf. In 2003, the gas testing of Permian Changxing Formation at Well Pengshen10 deployed within the shelf demonstrates a high-yield industrial gas flow of 206.36×10⁴m³/d, exhibiting the promising exploration prospects of biological reefs. Through petrographic and geochemical analyses based on core samples, solid bitumen samples as well as seismic and logging data, this study systematically investigates the stratigraphic and sedimentary characteristics, hydrocarbon accumulation conditions, periods and patterns of Changxing Formation at Well Pengshen10. The research results show as follows. (1)The Changxing Formation at Well Pengshen10 is composed of the pinnacle reef subfacies of shallow-water shelf. The reef reservoir is charaterized with abundant dissolution pores and structural fractures, forming a good reservoir-cap combination with the overlying Feixianguan Formation mudstone. (2)The geochemical characteristics of solid bitumen in natural gas reservoir demonstrate the contributions of source rocks from Longtan Formation and Qiongzhusi Formation. The Pengshen10 well area has developed a deep-seated strike-slip fault that runs through the Sinian Dengying Formation and the Permian Changxing Formation, serving as a key channel for vertical oil and gas migration. The lithologic traps are primarily developed in Changxing Formation at Well Pengshen10. (3)The homogenization temperature of inclusions and the burial-thermal history of reservoirs jointly reveal that hydrocarbon charging mainly occurred in the Early Triassic and Middle to Late Jurassic. Based on this, combined with the development of faults and traps during the oil and gas charging period, a hydrocarbon accumulation model was ultimately established, involving multi-source hydrocarbon supply, fault-mediated migration, as well as oil-gas accumulation and adjustment in the lithological and structural traps. The exploration breakthrough at Well Pengshen10 reveals that it is a representative area for the large-scale hydrocarbon accumulation in biological reefs over the shallow-water shelves, which points out a new direction for the exploration and deployment of natural gas in the Permian-Triassic reef shoal reservoirs of Sichuan Basin.

利用野外、钻井和地震资料综合研究，在四川盆地广元—巴中地区发现中二叠世的槽谷，为上扬子西 北缘受海西期拉张作用形成的拉张槽。拉张槽的地质—地震特征明显，呈北西向展布，宽度为70～120km，面积约 为2×104km2，根据其中线展布将其命名为广元—巴中拉张槽。拉张槽控制着中二叠统的烃源岩展布，拉张槽内为深 水欠补偿沉积，充填10～30m 的深水陆棚相泥质岩，TOC 为2%～9%，为优质烃源岩。该拉张槽还控制着中二叠统 茅口组台缘带优质储层的形成与展布，拉张槽两侧发育台地边缘滩相沉积，三维地震资料解释表明，台缘带宽度为 8～10km，面积达3000km2，受岩溶等成岩作用改造，可形成规模优质储层。广元—巴中拉张槽的发现改变了四川盆 地二叠纪构造沉积分异形成于长兴期的传统认识，拉张槽内部优质烃源岩与其周缘规模滩相储层构成旁生侧储的源储 配置关系，为有利成藏组合，是茅口组重要勘探方向。

Based on the comprehensive analysis of outcrop, drilling and seismic data, a Middle Permian trough is discovered in the Guangyuan-Bazhong area of the Sichuan Basin. And it is an extensional trough which is formed under the effect of Hercynian tension along the northwestern margin of Upper Yangtze, and its geological-seismic characteristics are obvious. It is extended in the direction of northwest, with a width of 70-120 km and an area of about 2?04 km2. According to the distribution of its central line, it is named as Guangyuan-Bazhong extensional trough. This extensional trough controls the distribution of the Middle Permian hydrocarbon source rocks. Inside the extensional trough are deepwater undercompensation sediments. It is filled with argillaceous rocks of deepwater shelf facies with the thickness of 10-30 m and its TOC ranges from 2% to 9%, so it is classified as high-quality hydrocarbon source rock. It also controls the formation and distribution of high-quality reservoirs in the platform margin belt of Maokou Formation, Middle Permian. The sediments of platform margin beach facies are developed on both sides of the extensional trough. It is indicated from the 3D seismic data interpretation that the platform margin belt covers an area of 3000 km2 with a width of 8-10 km. Owing to the diagenetic reformation (such as karstification), large-scale high-quality reservoirs can be formed. The discovery of Guangyuan-Bazhong extensional trough changes the traditional understanding that the Permian tectonic sedimentary differentiation in the Sichuan Basin is formed in the Changxing Period. The high-quality source rocks inside the extensional trough and the large-scale reservoirs of beach facies in the periphery constitute the source-reservoir configuration relation of side generation and lateral preservation, they are the favorable reservoir-forming assemblages and the importation exploration direction of the Maokou Formation.

Dolomitization and dolomite distribution are the key factors that restrict the development and distribution of reservoir of the 2nd member of Maokou Formation in central Sichuan Basin.Based on the previous research results of dolomite and the understanding of regional geological background,through the observation of core and thin sections,and the introduction of cathode luminescence,X-ray diffraction,inclusion,C and O stable isotope,Sr isotope and REE analysis,the further study of dolomitization of the 2nd member of Maokou Formation in central Sichuan Basin has been carried out.The results show that:(1)There are three types of dolomite in the study area:very fine-fine crystalline anhedral dolomite,very fine-medium crystalline euhedral dolomite,and saddle dolomite.Very fine-fine crystalline anhedral dolomite is formed by syngenetic evaporative seawater dolomitization.This dolomitization does not produce reservoir space itself,but plays a fundamental role in the formation of dolomite reservoirs.Very fine-medium euhedral dolomite is formed by burial dolomitization in the early diagenetic period,and the intergranular pores and intergranular dissolution pores are developed at the site of dolomitization,which can form dolomite dissolution pore type reservoir.Saddle dolomite is formed by hydrothermal dolomitization in early diagenetic period(Dongwu period).This dolomitization is accompanied by hydrothermal fracture and hydrothermal dissolution,which can lead to the development of dissolution fractures and the formation of dolomite dissolution fracture and cavernous reservoirs.(2)Marginal platform,coupling with the platform margin fault,is the best place to develop syngenetic seawater dolomitization,burial dolomitization and hydrothermal dolomitization in the early diagenetic period,and is also the advantageous development zone of dolomite reservoir.In the intra-platform highland area,syngenetic evaporative seawater dolomitization and burial dolomitization in the early diagenetic period are mainly developed,making it a relatively favorable zone for dolomite reservoir development.However,intra-platform depressions lack favorable conditions for dolomitization,resulting in poor dolomite development.

近年来四川盆地蓬深10、合深9、潼深17和正阳1等井钻探证实深层上二叠统长兴组发育一套孔隙型礁滩复合体灰岩储层，突破了深层碳酸盐岩大油气田主要分布于孔隙型白云岩储层和岩溶缝洞型灰岩储层的传统认识。基于岩心和薄片观察、储层地球化学特征分析、井震联合的储层识别和追踪，开展深层礁滩灰岩孔隙形成机理研究，取得4个方面认识：①深层长兴组孔隙型礁滩复合体灰岩储集空间以粒间孔、格架孔、生物体腔孔、铸模孔和溶孔为主，形成于沉积和早表生环境；②断续分布的多孔礁滩复合体被相对致密的泥晶灰岩包裹，在复合体持续增温条件下导致局部异常高压的形成；③长兴组储层的底板为上二叠统吴家坪组互层的致密泥岩和灰岩，顶板为下三叠统飞仙关组一段致密泥晶灰岩夹泥岩，在致密顶底板的夹持下，导致长兴组区域异常高压的形成；异常高压（超压封存箱）是沉积和早表生环境形成的孔隙在深层得以保持的关键；④在顶底板和礁滩复合体识别基础上，通过井震联合预测有利礁滩灰岩储层分布面积达10.3×10⁴ km²。上述认识奠定了深层孔隙型灰岩储层发育的理论基础，拓展了四川盆地深层灰岩储层勘探新领域。

近年来，绵阳—广安浅水陆棚及周缘地区长兴组勘探获得重大突破，但不同礁滩体天然气地球化学特征及含气性差异大，天然气成因来源及主力烃源不清, 油气富集规律及成藏模式不明，制约了有利圈闭评价及勘探部署。基于天然气组成、碳同位素、氢同位素、氮同位素、储层沥青与烃源岩等分析实验数据，系统研究了天然气成因、混源气的混源比例，结合地质研究成果，建立了长兴组气藏成藏模式。研究结果表明：（1）长兴组天然气是以烃类气体为主且干燥系数大于0.98的干气，主要属于原油裂解气，部分为中—高含H₂S气藏。（2）研究区主要发育上二叠统龙潭组/ 吴家坪组Ⅱ₁—Ⅲ型和下古生界筇竹寺组Ⅰ型、龙马溪组Ⅰ—Ⅱ₁型3套烃源岩，长兴组天然气地球化学特征差异与主力烃源岩发育程度及通源断裂断开层位相关。源于上二叠统烃源岩的天然气碳同位素重，δ¹³C₂值主要重于-28.0‰；有下古生界烃源混入时，混合气的碳同位素变轻，采用端元气δ¹³C₂值估算的下古生界源岩贡献比例为53.9%～77.0%。（3）长兴组气藏具有单源供烃、双源供烃和三源供烃3类聚集模式，明确了不同聚集模式的主力烃源岩。研究认为，以上二叠统龙潭组/吴家坪组为烃源的区域，规模滩相储层叠加现今构造是有利勘探区；存在下古生界混源的区域，通源断裂与规模滩相储层的有效匹配，使油气富集程度整体较高，可为四川盆地下步勘探部署决策提供地质依据。

In recent years, significant breakthroughs have been made in the exploration of the Upper Permian Changxing Formation in the Mianyang-Guang’an shallow-water shelf and its adjacent areas. However, the geochemical characteristics and gas-bearing properties of different reef-shoal bodies vary greatly, the genesis and main source rocks of different gas reservoirs remain unclear, and the laws of oil and gas enrichment and the accumulation models are not yet well understood. These factors have restricted the evaluation of favorable traps and the deployment of exploration. Based on the analysis and experimental data of natural gas composition, carbon isotopes, hydrogen isotopes, nitrogen isotopes, reservoir bitumen and source rocks, a systematic study was conducted on the origin of natural gas and the mixing ratio of mixed gases. Combined with geological research results, a gas accumulation model for the Changxing Formation was established. The research results show that: The study results show that: (1) The natural gas in the Changxing Formation is mainly composed of hydrocarbon gases with a dryness coefficient greater than 0.9841, and it is mainly pyrolysis gas from crude oil, with some being medium to high H₂S gas reservoirs. (2) In the study area, three sets of source rocks of two types, namely the Upper Permian Longtan Formation/Wujiaping Formation Type II₁-III and the Lower Paleozoic Qiongzhusi Formation and Longmaxi Formation Type I-II₁, are mainly developed. The geochemical differences of natural gas in the Changxing Formation are related to the development degree of the main source rocks and the stratigraphic level of the source-cutting faults. Natural gas from the Upper Permian source rocks has heavy carbon isotopes, with δ¹³C₂ values mainly heavier than -28.0‰. When Lower Paleozoic source rocks are mixed in, the carbon isotopes of the mixed gas become lighter. The contribution ratio of Lower Paleozoic source rocks estimated by the end-member gas δ¹³C₂ values is 53.9% - 77.0%. (3) The Changxing Formation gas reservoirs have three types of accumulation patterns：single-source，dual-source and triple-source hydrocarbon supply pattern. The main source rocks and their distribution for different accumulation patterns were clarified. It is believed that in the area where the source rocks are from the Upper Permian Longtan Formation/Wujiaping Formation, the superimposition of large-scale beach facies reservoirs and the current structure is a favorable exploration zone. In the area where there is a mixture of Lower Paleozoic sources, the effective matching of source-cutting faults and large-scale beach facies reservoirs leads to a higher overall degree of oil and gas enrichment，which can provide geological basis for the next exploration deployment decisions in Sichuan Basin.