Foreland basins are shaped by the sedimentary architecture and lithospheric flexure due to the sediment load, slab pull, orogenic growth, and asthenospheric mantle flow. However, it is challenging to differentiate foreland basins from rift basins due to the destructive effects of multiphase orogenesis. Situated at the core of the western Central Asian Orogen Belt, the Junggar Basin holds vital clues regarding the closure of the Paleo-Asian Ocean. There is debate regarding whether it was a compressional foreland basin or an extended rift after the closure of the surrounding oceans. Furthermore, uncertainties persist regarding the fate of the residual oceanic crust and the precise tectonic processes during the collision of the ocean-arc-continent system. Understanding the basin's style during the early Permian period is crucial for deciphering its dynamic tectonic history. This study leverages regional seismic data to reevaluate the overall structure of the Junggar Basin, providing insights into its tectonic context and the mechanisms of intraplate deformation during the early Permian period. The findings reveal significant early Permian deformation features characterized by varying strata thicknesses and unconformities, signifying continuous tectonic activity during deposition. The western and southern depressions that developed from the late Carboniferous to early Permian are in keeping with compressional dynamics and reflect a foredeep basin, while the central uplift corresponds to a forebulge. This study posits that the observed foreland basin system was shaped by lithospheric flexure at the end of the late Carboniferous and lithospheric buckling in the early Permian, which contributed to the creation of uplifted Mosuowan-Baijiahai forebulge in the interior. The Junggar Basin featured a convergent dynamic environment, although the surrounding orogen transitioned into a postcollisional orogen in the Central Asian Orogenic Belt during the early Permian.

Despite the ubiquity of hydrothermal fluid circulation in the crust, its timing is difficult to precisely determine using traditional thermometric dating due to strongly disturbed geothermal fields. We present a case study from the mid-Permian hydrocarbon-bearing dolostone reservoirs, situated proximally to strike-slip faults in the central Sichuan Basin (China), to highlight the utility of carbonate in-situ U-Pb geochronology in delineating the timing of hydrothermal fluid flow. Matrix and void-filling cement dolomite phases were identified in the porous Maokou Formation carbonates. Predominantly manifesting as saddle dolomites along fractures, these cements yielded statistically homogeneous U-Pb ages (242.5 +/- 3.1 Ma, 238.9 +/- 8.2 Ma, 244 +/- 15 Ma, and 239.2 +/- 6.5 Ma), slightly postdating the established stratigraphic timeline (ca. 273 to 259 Ma). The narrow temporal span suggests early emplacement following a short burial, compatible with the petrographic observation of burial stylolites crosscutting saddle dolomites. Integrating shallow emplacement depths inferred from a comparison between the dolomite U-Pb ages and a published burial history, with fluid-inclusion microthermometry, elucidates the hy-drothermal system that was once present in this field. The pervasive occurrence of hydrofracturing, along with dolomite geochemical indicators represented by bell-shaped (REE + Y) PAAS patterns and elevated Y/Ho ratios, provide additional evidence for the hydrothermal fluid injection and resulting dolomitization. The dolomites' positive Eu anomalies and the parent fluids' 18O enrichment indicate a source from deeper basinal pore waters that have interacted significantly with ambient rocks. The overlying Triassic evaporites may have provided Mg -rich brines, mixing into the circulating hot fluids responsible for hydrothermal dolomitization. Our dolomite U-Pb ages coincide with the seismically estimated timing of transtensional strike-slip fault activation. This temporal correspondence, combined with spatial associations and lateral slickensides along fracture planes, suggests that the hydrothermal fluid movement is highly relevant to the active strike-slip faults. This observation reveals a previously unrecognized early-middle Triassic, structurally controlled hydrothermal activity in the region. We propose that this episode of hydrothermal circulation was driven by extensional tectonism in response to the spreading of the Proto-Tethys Ocean. This finding is not in line with the earlier research that considered late Permian Emeishan volcanism to have been the main trigger for hydrothermal fluid influx. The long-standing view regarding hydrothermal dolomitization in this region may need to be re-evaluated.

Based on the global basement reservoir database and the dissection of basement reservoirs in China,the characteristics of hydrocarbon accumulation in basement reservoirs are analyzed,and the favorable conditions for hydrocarbon accumulation in deep basement reservoirs are investigated to highlight the exploration targets.The discovered basement reservoirs worldwide are mainly buried in the Archean and Precambrian granitic and metamorphic formations with depths less than 4 500 m,and the relatively large reservoirs have been found in rift,back-arc and foreland basins in tectonic active zones of the Meso-Cenozoic plates.The hydrocarbon accumulation in basement reservoirs exhibits the characteristics in three aspects.First,the porous-fractured reservoirs with low porosity and ultra-low permeability are dominant,where extensive hydrocarbon accumulation occurred during the weathering denudation and later tectonic reworking of the basin basement.High resistance to compaction allows the physical properties of these highly heterogeneous reservoirs to be independent of the buried depth.Second,the hydrocarbons were sourced from the formations outside the basement.The source-reservoir assemblages are divided into contacted source rock-basement and separated source rock-basement patterns.Third,the abnormal high pressure in the source rock and the normal-low pressure in the basement reservoirs cause a large pressure difference between the source rock and the reservoirs,which is conducive to the pumping effect of hydrocarbons in the deep basement.The deep basement prospects are mainly evaluated by the factors such as tectonic activity of basement,source-reservoir combination,development of large deep faults(especially strike-slip faults),and regional seals.The Precambrian crystalline basements at the margin of the intracontinental rifts in cratonic basins,as well as the Paleozoic folded basements and the Meso-Cenozoic fault-block basements adjacent to the hydrocarbon generation depressions,have favorable conditions for hydrocarbon accumulation,and thus they are considered as the main targets for future exploration of deep basement reservoirs.

In the Precambrian dolomites in the central Sichuan Basin, a substantial paleo-oil system previously existed, which has since evolved into a dry gas system that is currently in place. The genesis of this paleo-oil system remained poorly understood, leaving uncertainties regarding the timing of oil charging and associated source rocks. Integration of Re-Os geochronometry with basin modeling allows temporal-spatial constraints on the ancient petroleum system to be established. Two texturally distinct generations of reservoir bitumen were identified. Late-generation bitumen yielded a geologically meaningful Re-Os age of 189 & PLUSMN; 20 Ma (MSWD = 10.4, 2 & sigma;), distinct from the previously documented Re-Os ages such as the 414 & PLUSMN; 44 Ma reported by Shi et al. (2020). This new age, along with the -414 Ma, aligns within uncertainties with the two relative timings derived from our independent basin model (ca. 450-390 Ma and 260-180 Ma), revealing two temporally distinct oil generation-migration events. The date of -189 Ma also lends support to the previous oil charge timing inferred from fluid inclusions. We evaluated the imprecisions of these two Re-Os ages and considered them to result from a narrow spread in 187Re/188Os, and variations in initial Os isotopic compositions (Osi) due to the giant size of the petroleum system and a long duration of oil generation from source kitchen over a large geographical area in this play. Effects of asphaltene precipitation, due to upliftinduced decompression of the migrating oils, may also have contributed to the scatter. Separating the samples based on Osi produced a higher precision age (184.1 & PLUSMN; 5.7 Ma, Model 1) with an MSWD of 0.97.The first oil charge is relatively weak as shown by the basin model and observed bitumen volumes, and it had not been well preserved due to significant reservoir exhumation by Caledonian tectonism. Consequently, the younger oil charge is considered to be the principal precursor to the current dry gas accumulations. Os isotope histories for four potential source units were constructed using publicly available Re-Os data. Comparisons between bitumen and rock Os compositions tend to support the lower Cambrian Qiongzhusi Formation as the predominant source unit for the two major paleo-oil charges. However, contributions from the Duoshantuo, Dengying, and Maidiping source rocks can not be precluded. Overall, these new observations allow temporalspatial constraints to be placed on the complex evolution, from paleo-oil generation to destruction and dry gas generation.

走滑断裂对油气成藏具有重要的控制作用.为了探究四川盆地高石梯-磨溪地区走滑断裂在震旦系-寒武系油气成藏中的控藏作用,在走滑断裂的精细地震解释,以及储层溶蚀孔洞充填成岩矿物流体包裹体系统分析的基础上,通过划分走滑断裂活动期次,以及拟定油气充注成藏期次和时期,并探讨二者之间的耦合关系,从而建立油气成藏模式.结果表明,四川盆地高石梯-磨溪地区存在加里东早期、加里东晚期-海西早期、海西晚期及印支期4期走滑断裂,震旦系-寒武系总体存在两期油三期气充注成藏的特征.走滑断裂的活动与油气活动存在良好的时空耦合关系,从而形成了震旦系-寒武系走滑断裂控制下的"层楼式"油气成藏模式.该模式下,走滑断裂垂向连通主力烃源岩与多套优质储层,形成多层系含有油气的格局,且各层系油气成藏特征表现出高度相似性.对存在"层楼式"油气成藏模式的地区,应注重立体勘探.

In 2022, the risk exploration well Chongtan1 (CT1) in the Sichuan Basin revealed commercial oil and gas flow during test in a new zone – the marl of the second submember of the third member of Leikoupo Formation (Lei-32) of Middle Triassic, recording a significant discovery. However, the hydrocarbon accumulation in marl remains unclear, which restricts the selection and deployment of exploration area. Focusing on Well CT1, the hydrocarbon accumulation characteristics of Lei-32 marl are analyzed to clarify the potential zones for exploration. The following findings are obtained. First, according to the geochemical analysis of petroleum and source rocks, oil and gas in the Lei-32 marl of Well CT1 are originated from the same marl. The marl acts as both source rock and reservoir rock. Second, the Lei-32 marl in central Sichuan Basin is of lagoonal facies, with a thickness of 40–130 m, an area of about 40 000 km2, a hydrocarbon generation intensity of (4–12)×108 m3/km2, and an estimated quantity of generated hydrocarbons of 25×1012 m3. Third, the lagoonal marl reservoirs are widely distributed in central Sichuan Basin. Typically, in Xichong–Yilong, Ziyang–Jianyang and Moxi South, the reservoirs are 20–60 m thick and cover an area of 7500 km2. Fourth, hydrocarbons in the lagoonal marl are generated and stored in the Lei-32 marl, which means that marl serves as both source rock and reservoir rock. They represent a new type of unconventional resource, which is worthy of exploring. Fifth, based on the interpretation of 2D and 3D seismic data from central Sichuan Basin, Xichong and Suining are defined as favorable prospects with estimated resources of (2000–3000)×108 m3.

针对四川盆地川中古隆起高磨三维区震旦系-古生界二叠系海相碳酸盐岩层系不同尺度的断裂,特别是小型走滑断裂在地震资料上难以识别和解释的难点,利用地震数据及其属性携带的断裂结构信息、不连续性变化信息、裂缝带信息,优选应用构造导向滤波技术、本征值相干技术、分频相干与分方位相干技术、最大正/负曲率属性技术、蚂蚁体技术、最大似然断裂识别技术、PADD(poststack amplitude direction decomposition,叠后振幅方位分解)技术,分层系、分方位、分尺度逐级精细识别和描述了地震波同相轴错断型断裂、同相轴挠曲型断裂、裂缝型微小断裂,以及岩溶塌陷体,并应用成像测井裂缝信息定性验证不同尺度断裂方位和断裂密度,井震吻合效果好.集成形成"三分八步"逐级控制下的断裂地震识别技术方法系列.并根据地质模型和断裂模式判别了走滑断裂,进行了分级,总结了川中高磨区6种走滑断裂构造样式.

The formation and evolution of dolomite reservoirs in the Sinian Dengying Formation in the Sichuan Basin have attracted much attention recently. Due to their economic significance for hosting natural gas resources, determining the key factors that govern the formation and evolution of these dolomite reservoirs are important for hydrocarbon exploration and development. Based on the drilling and seismic data in the Penglai-Zhongjiang area of the Sichuan Basin, the main controlling factors for the development of high-quality reservoirs in the second member of Dengying Formation are investigated by integrating core and thin section observation and geochemical analysis. Lithologies of the reservoirs in the second member of Dengying Formation are dominantly microbial dolomites, dolo-grainstones, and brecciaed dolomites. Moreover, reservoir spaces in these dolomites are mostly dissolution pores, residual framework pores, and breccia pores. The porosity ranges from 2.0% to 8.0% with an average of 4.39%, and the average permeability is 0.53×10-3 μm2, and the reservoir thickness is 170-320 m. Synsedimentary faulting had caused the differentiation of depositional paleo-geomorphology and led to the formation of submarine high barriers, which provided favorable conditions for the development of microbial mound (reef) and shoal complexes. Furthermore, fault activities could have broken the weakly consolidated carbonate sediments into breccias, thus resulting in the brecciaed dolomite reservoir. Penecontemporaneous dissolution is the key to the development of high-quality reservoirs in the second member of the Dengying Formation, which is consistent with their occurrence in the upper part of the shallowing-upward cycles. Differentiation in microfacies leads to distinct diagenetic pathways and porosity evolution of these microbial-dominant carbonate sediments. Overall, dolomite cementation during shallow burial had controlled thedegree of pore preservation. It is predicted that three fault-controlled, platform-margin mound regions in the study area, i.e., Penglai-Zhongjiang, Yanting-Mianyang, and Cangxi-Guangyuan, with areas of 1 600 km2, 1 870 km2 and 2 280 km2, respectively, had been developed in the second member of Dengying Formation in the north slope of the central Sichuan paleo-uplift, showing multi-stage and multi-zone characteristics. Microbial mounds in the platform margin of the second member of Dengying Formation in the Yanting-Mianyang and Cangxi-Guangyuan areas, with three sets of high-quality source rocks, may form a variety of favorable source-reservoir combinations. Additionally, the accumulation conditions may have been superior. The estimated natural gas resources in the study area, over one trillion square meters, makes it a favorable area for ultra-deep carbonate exploration and is expected to be a breakthrough site for the next one trillion square gas field in the Sichuan Basin.

When the target magnetic structures have clear interfaces and significant petrophysical contrasts to the surrounding strata, the focusing (or sharp-boundary) inversion methods are preferred over the smooth inversion methods. The result of focusing inversions depends on the types of the focusing model constraint (stabilizer). In this study, we propose an adjustable exponential minimum support (AEMS) stabilizer, which is an extension of the previously introduced exponential minimum support (EMS) stabilizer. AEMS is similar to EMS, but it includes an adjustable focusing scheme to control the sharpness of the resulting structure. Using synthetic models, we compared the inversion results obtained with the AEMS method to those obtained by smoothing stabilizers and other focusing stabilizers. AEMS inversion results have a more accurate physical-property distribution and are closer to the true models, indicating an improved model recovery from the other inversion methods. The improvement is mainly attributed to the adjustable scheme of the focusing parameter in the AEMS method. Then, we inverted a field dataset using the AEMS inversion method to obtain a new reference model for copper-gold porphyry deposit detection and interpretation.

Alongside volcanic eruptions in the middle and late Permian, the sedimentary environment and process changed, and the lithofacies and mineralogical characteristics varied conspicuously from the marine sediments in this period. Marine tuffaceous rocks beared strong witness to the marine and volcanic actions in this time. With experimental studies relying on field outcrop, thin section, scanning electron microscope, X-ray diffraction (XRD), mercury injection capillary pressure (MICP) and CT scan, the researchers analyzed the lithology, mineralogy, and pore characteristics of marine tuffaceous rocks. Among the Permian marine tuffaceous sections of the Sichuan Basin, three types of lithofacies were identified, namely tuff, sedimentary tuff, and tuffaceous mudstone. The mineral composition of the tuffaceous section includes quartz, feldspar, carbonate minerals, pyrite, clay, etc. The quartz content varies from 4.0% to 27.3%, with an average value of 13.0%; the feldspar content varies from 0 to 21.2%, with an average value of 9.8%; the carbonate mineral content varies from 8.52% to 53.45%, with an average value of 27.6%; the clay mineral content varies from 0 to 75.3%, with an average value of 44.8%; and the pyrite content varies from 0 to 13.4%, with an average value of 5.8%. The porosity of tuffaceous rocks varies from 2.2% to 8.1%, mostly concentrated in the range from 3% to 7% with an average level of 5.24%. There are mainly shrinkage pores, dissolution pores, intercrystalline pores, and organic pores. In terms of scale, the pores can be classified as micron-scale and nano-scale pores, and in terms of size, they are mainly micropores and mesopores, accounting for up to 92.12%. The pores are concentrated in the tuffaceous section and well interconnected, forming a complex organic-inorganic pore-fracture network system and bedding fractures with even better connectivity. The pores of the tuffaceous section are greatly influenced by lithofacies and mineral composition. The porosities of tuffaceous mudstone, sedimentary tuff and tuff rank downward, with average porosities of 6.5%, 5.09%, and 3.86% respectively. The felsic content is inversely correlated with porosity; the clay content and TOC content are positively correlated with porosity; the pyrite content is also inversely correlated with porosity. The marine tuffaceous section is similar to shale to a certain extent as it has relatively dense lithology, its pores are mainly of micron-scale and nano-scale and mainly include micropores and mesopores. It boasts the hydrocarbon-generating capacity and reservoir performance, serving as both a source rock and a reservoir. As a novel reservoir, the tuffaceous section can form a tight reservoir both generating and depositing gas and featuring source-reservoir paragenesis, lithological reservoir-controlling, and large-area stratified distribution, manifesting a promising future for exploration.

Alongside volcanic eruptions in the middle and late Permian, the sedimentary environment and process changed, and the lithofacies characteristics varied conspicuously in the marine deposits of the Sichuan Basin (China). The tuffaceous rocks, as a new type of unconventional reservoir, provide strong evidence for marine and volcanic influences on the lithology and reservoir potential of the rocks. With experimental studies relying on field outcrops, thin sections, scanning electron microscopy and whole-rock X-ray diffraction (XRD), the researchers analyzed the lithofacies characteristics, pore types and controlling factors on the various types of pores in the tuffaceous rocks. We identified three lithofacies types in this new type of Permian reservoir in the Sichuan Basin, namely tuff, sedimentary tuff, and tuffaceous mudstone. The mineral composition of the three lithofacies includes quartz, feldspar, carbonate minerals, pyrite, and clay, among which feldspar is mainly potassium feldspar. Tuff has high tuff content, and the lowest clay and TOC content; tuffaceous mudstones have the highest clay and TOC content, and the lowest tuff content. The pore types of the tuffaceous rocks are mainly nano-scale shrinkage pores, with a small number of intergranular pores including intragranular pores, intergranular pores, and organic pores. The shrinkage pores account for 81.9% of the total pores, and organic pores account for 11.2% of the total pores. In the tuffaceous rocks, the tuff content, quartz and feldspar content, and pyrite content are inversely correlated with porosity, while the clay content and TOC content are positively correlated with porosity. The porosity of tuff is the lowest, followed by sedimentary tuff, and the porosity of tuffaceous mudstone is the highest. Tuffaceous rocks form many micropores in the process of devitrification. Organic matter pyrolysis and organic acid dissolution also increase the reservoir space and porosity of the reservoir. This new type of reservoir has the ability of hydrocarbon accumulation along with the reservoir performance, and thus it has greater exploration prospects.

为明确四川盆地中西部走滑断裂与油气成藏的关系,基于三维地震断裂解释,缝洞充填物定年和已发现气藏解剖,揭示了走滑断裂特征、主要活动时期和对油气成藏的控制作用.走滑断裂主要见于震旦系-古生界地层,可划为3个断裂构造变形层;平面上主要分布于川中古隆起及斜坡区,以近EW和NWW-SEE向为主,存在6条近EW向走滑断裂带和两条NW-SE向逆冲断裂带,加里东期-海西早期、海西晚期-印支期和燕山中期-喜山期是走滑断裂主要活动时期.走滑断裂沟通了多套源储组合,对盆地中西部海相多层系立体成藏控制作用明显,已发现油气田和高产井主要分布在走滑断裂带;建立了走滑断裂4种差异化立体成藏模式,指出7个有利勘探区带,可为勘探部署提供理论认识依据.

Economically viable accumulations of hydrocarbons hosted in the Precambrian rocks are globally rare, as a protracted history available for them to escape or be destroyed due to various processes including thermal and bacterial degradations and tectonic disruption. A recent gas discovery in the late Ediacaran dolomites of the Sichuan Basin (SW China) provides an opportunity to understand the formation and preservation of ancient petroleum systems. Paleo fluid pressure-temperature-composition (P-T-X) conditions from deep burial to exhumation are evaluated from microthermometry and Raman data obtained from fluid inclusions. We identified three texturally distinct generations of gas-bearing fluid inclusion assemblages (FIAs), which delineate an operating petroleum system where gas remigrated during exhumation that followed oil cracking during deep burial. The older FIAs (types 1 and 2) show a petrographic association with bitumen and are interpreted to be the result of thermal cracking. Type 1 FIAs formed through in-situ cracking of pre-existing oil inclusions and have recorded the paleo oil charge during the middle Triassic to early Jurassic. Type 2 FIAs were trapped during the prolonged intra-reservoir oil cracking that occurred between the late Jurassic and late Cretaceous. Our pore pressure calculations indicate overpressured conditions, a result of active gas generation during thermal cracking. Lithostatic overpressures accumulated and were sustained under weak tectonic compression prior to peak burial. Type 3 FIAs have been interpreted as reflective of the gas-bearing system reactivation during exhumation. These FIAs indicate the relative reduction in the proportion of aqueous to gas inclusions, which may be due to a decrease in water saturation following gas emplacement. Uplift processes during early exhumation likely facilitated breaching of the system and remobilization of fluids, resulting in gas escape and overpressure release. The drastic increase in formation water salinity, which was documented in the fluid inclusion dataset, points to the arrival of hypersaline brine during the Eocene to Oligocene. This brine could have originated either from the lower Cambrian evaporated CaCl2 seawater or from the dissolution of the lower-middle Triassic halite. From the late Miocene to present, progressively exhumed reservoirs may have received an influx of relatively fresh water from shallow aquifers, as shown by the correspondence between P-T-X records and present-day reservoir conditions.

Based on the latest drilling, seismic and field outcrop data, the geological characteristics (e.g. strata, development and sedimentary evolution) of the southern segment of the Late Sinian—Early Cambrian Deyang—Anyue rift trough in the Sichuan Basin are analyzed. First, the strata in the southern segment are complete. The first to second members of Dengying Formation (Deng 1 + Deng 2) are found with relatively stable thickness (400–550 m), and the third to fourth members (Deng 3 + Deng 4) show great thickness difference between the marginal trough and the inner trough, which is up to 250 m. The Cambrian Maidiping Formation and Qiongzhusi Formation in southern Sichuan Basin are relatively thin, with the thickness changing greatly and frequently. Second, the Deyang—Anyue rift trough extended southward during the Deng 4 period, affecting southern Sichuan Basin. Compared to the middle and northern segments of the rift trough, the southern segment is generally wide, gentle and shallow, with multiple steps, and alternating uplifts and sags, which are distributed in finger shape. Third, the Deng 1 + Deng 2 in southern Sichuan Basin records the dominance of carbonate platform and unobvious sedimentary differentiation, and the Deng 4 exhibits obvious sedimentary differentiation, namely, basin—slope—secondary slope—slope—secondary slope—platform margin—restricted platform, from the inner trough to the marginal trough. Fourth, the rift trough in southern Sichuan Basin has evolved in four stages: stabilization of Deng 1—Deng 2, initialization of Deng 3—Deng 4, filling of Maidiping—Qiongzhusi, and extinction of Canglangpu Formation.

以古生界为主的海相碳酸盐岩是我国陆上油气勘探的重点领域,勘探开发成效显著.随着勘探不断发展,超深层、更古老海相层系油气成藏富集规律的认识面临挑战.本文从古老小克拉通盆地构造分异的角度,剖析油气成藏富集规律.通过对四川、塔里木和鄂尔多斯等克拉通盆地演化过程中的构造分异作用研究,认为克拉通盆地构造分异对沉积、成储与成藏组合有显著的控制作用.构造分异控制的三类油气聚集带是未来超深层海相碳酸盐岩油气勘探的重点领域.

The Cambrian Longwangmiao gas reservoirs in the Moxi area of the Sichuan Basin have a complex associated gas accumulation history. Based on core and thin section examination, fluid inclusion analyses and 1-D burial-thermal modelling, the diagenetic evolution and hydrocarbon accumulation processes in the Longwangmiao Formation have been reconstructed. Various diagenetic events were identified, making up a complete pore fill sequence as follows: solid bitumen/dolomite→ nonfluorescent solid bitumen → dolomite → quartz/yellow fluorescent oily bitumen → residual hole. Analyses of oil inclusions and bitumen-bearing inclusions are key to the understanding of the hydrocarbon accumulation processes. The Th values of the aqueous inclusions that are contemporaneous with hydrocarbon inclusions range from 74.3 to 214.3°C. In conjunction with burial-thermal history modelling results, the results indicate that there were two stages of oil charge and three stages of natural gas accumulation in the Longwangmiao carbonate reservoirs. The two stages of oil charge occurred in the Late Silurian and Middle Triassic, respectively. Three gas accumulation events occurred in the Middle to Late Triassic, Middle Jurassic to Early Cretaceous, and Late Cretaceous, respectively.

松辽盆地的油气勘探开发已进入中后期,盆地内地热资源的开发利用前景也逐渐显现.然而,受到钻井测温条件的限制,松辽盆地北部的地温场研究较为薄弱.为此,应用该盆地在石油勘探开发和最新地热调查中所取得的区域地质、钻井、地球物理、岩石物性及盆地热状态等资料,建立了松辽盆地北部的三维地质模型,在热边界条件的限制下利用三维热传递方程进行了区域地温场模拟,并通过与实测钻井测温曲线的对比验证了模型的可靠性.研究结果表明:①松辽盆地北部以热传导为主要热传递机制,区域地温场的分布主要受到基底热流、地层热物性及盆地构造格架的控制;②在1km、2 km、3 km深度界面,地温分别介于40～60℃、75～110℃、115～150℃,中央坳陷区内的局部高温区位于大庆长垣及朝阳沟阶地,盆地东部基底隆起区域表现出更高温度;③沿近东西向,地温场等值界面呈近层状分布,基底隆起区对应地温等值线高值区,5 km深度地温介于200～225℃;④模拟数据与实测数据间存在一定偏差,模型误差可能来自于局部对流活动的存在以及三维地质模型和边界条件的不精确性.结论认为,松辽盆地北部具有形成沉积盆地中低温水热型地热资源的地温场条件,其中下白垩统泉头组三段、四段为有利的目标热储层.

Based on the contemporary strategy of PetroChina and the "Super Basin Thinking" initiative, we analyze the petro-leum system, the remaining oil and gas resource distribution, and the Super Basin development scheme in the Sichuan Basin with the aim of unlocking its full resource potential. We conclude that, (1) The three-stage evolution of the Sichuan Basin has resulted in the stereoscopic distribution of hydrocarbon systems dominated by natural gas. The prospecting Nanhua-rift stage gas system is potentially to be found in the ultra-deep part of the basin. The marine-cratonic stage gas system is distributed in the Sinian to Mid-Triassic formations, mainly conventional gas and shale gas resources. The foreland-basin stage tight sand gas and shale oil resources are found in the Upper Triassic Jurassic formations. Such resource base provides the foundation for the implementation of Super Basin paradigm in the Sichuan Basin. (2) To ensure larger scale hydrocarbon exploration and pro-duction, technologies regarding deep to ultra-deep carbonate reservoirs, tight-sand gas, and shale oil are necessarily to be ad-vanced. (3) In order to achieve the full hydrocarbon potential of the Sichuan Basin, pertinent exploration strategies are ex-pected to be proposed with regard to each hydrocarbon system respectively, government and policy supports ought to be strengthened, and new cooperative pattern should be established. Introducing the "Super Basin Thinking" provides references and guidelines for further deployment of hydrocarbon exploration and production in the Sichuan Basin and other developed ba-sins.

安岳大气田的发现,推动了板内裂陷动力学及沉积充填过程研究,但目前有关德阳—安岳裂陷成因及演化认识尚存争议.通过大量地震资料解释,结合最新钻井资料,系统研究了裂陷演化成因及沉积充填特征,指出有利勘探区带.主要认识为:①德阳—安岳裂陷形成于晚震旦世—早寒武世,具有"北沉降、南侵蚀"差异演化特征.裂陷由北往南张裂,灯二期台地边缘在绵阳—蓬莱—大足—资阳地区发育;灯四期裂陷进一步向南延伸到泸州地区;灯影末期,裂陷北部沉降,中南部抬升剥蚀,部分地区灯三段和灯四段剥蚀殆尽.②德阳—安岳裂陷灯影末期北部沉降大于南部,沉降中心在绵阳—成都一带;麦地坪末期北部继续沉降,南部开始出现沉降;筇竹寺期形成绵阳—成都、宜宾—泸州南北2个沉降中心.③德阳—安岳裂陷周缘形成侵蚀型、加积型和退积型3类台缘储层,叠合寒武系麦地坪组—筇竹寺组厚层烃源岩,形成了蓬莱—剑阁—老关庙地区和资阳—威远地区2个有利勘探区带,勘探面积达3×104 km2.