尽管地热能的发展前景广阔,但随着地热能利用的优势逐渐显现,国内各大型企业已纷纷投身到新能源建设热潮中去,行业竞争日趋激烈.随着地热开发日渐火爆,各地政府纷纷出台规范性政策,对地热开发的手续、技术、管理等多方面提出更高要求,开发政策日趋严格.
The exploration for the Middle Permian Qixia Formation,an important successor to the Cambrian producing formations,has made great breakthroughs in recent years in the Gaoshiti-Moxi area of central Sichuan Basin.Based on core thin-section observation,natural gas geochemical analysis,and fluid inclusion thermometric analysis,the geological conditions for hydrocarbon accumulation in the Formation were discussed.Meanwhile,coupling with the restoration of regional burial-thermal evolution history,the main factors controlling the hy-drocarbon accumulation were identified,and the reservoir evolution process was revealed.The results indicate that the Qixia Formation has good geological conditions for hydrocarbon accumulation.(i)the Qixia Formation dolomite reservoirs contain pores,vugs and fractures,with multi-stage superimposed thin layers vertically.(ii)Natural gas is mainly supplied by the high-quality source rocks of the Lower Cam-brian,partially by some source rocks of the Middle Permian,and by certain source rocks of the Silurian Longmaxi Formation(mainly in the southern part of the study area).(iii)The E-W strike-slip faults serve as favorable pathways for the vertical migration of natural gas,commu-nicating the source rocks and reservoir rocks to favor the gas accumulation.(iv)The gas reservoirs of the Qixia Formation are currently lith-ologic reservoirs under the tectonic setting.These reservoirs have undergone an evolution process from the Indosinian oil paleo-reservoir to the Yanshan gas paleo-reservoir and then to the present gas reservoir.In this process,the study area did not suffer remarkable adjustment and transformation,and reflects in-situ enrichment and efficient accumulation of gas.
The Middle Permian Maokou Formation has been one of the major gas-producing horizons in the Sichuan Basin for more than half a century.A new exploration upsurge targeting the dolomite reservoirs has been set off in recent years.However,the lack of system-atical study on the genetic mechanisms of various reservoirs limits progressive exploration.To clarify the characteristics and genesis of do-lomite reservoirs in the second member of Maokou Formation in the Longnvsi area of central Sichuan Basin,the genetic mechanisms of the reservoirs were investigated with the tectonism and using the data of outcrops,drilling,logging,and seismic interpretation.The results show that,(i)the dolomite reservoirs in the Maokou Formation are primarily composed of fine-to medium-crystalline dolomites formed by the dolomitization of beach grainstones;(ii)the reservoir spaces are dominantly made of hydrothermal impact-induced vugs and non-selective karst vugs,followed by structural fractures and karst fissures which play an important role in hydrothermal migration and reservoir seepage enhancement;(iii)the Hercynian Emei taphrogeny and the basement faulting controlled by the northward subduction of the Mian-lue Ocean induced the formation of the northern Sichuan platform basin in the Late Middle Permian,and controlled the distribution of beach grain-stones at the margin of the platform basin;(iv)affected by the high paleogeothermal gradient,remnant marine-originated fluids,and abun-dant magnesium ions from hydrothermal fluids migrating along faults,the beach grainstones were dolomitized extensively;(v)the Hercynian fault-fracture-hydrothermal activity and the Indosinian fault-fracture activity controlled the space formation of the dolomite reservoirs;and(vi)tectonism is the key controlling mechanism for the formation of dolomite reservoirs.The areas where faults are concentrated should be focused on for progressive exploration.
There developed varying dolomitized reservoirs in the Middle Permian Maokou Formation,central Sichuan Basin,in which significant gas discoveries have been made recently.Thus,the reservoir characterization,the enquiry of dolomitization mechanisms and the identification of main controls are very meaningful tasks for next exploration and deployment.Based on the macroscopic and microscopic observation on cores and outcrop samples,as well as some analysis on geochemical features,the characteristics,genesis and main controlling factors were investigated for the dolomite reservoirs.Results show that(i)these Maokou reservoirs in central basin are developed in the upper Maokou 2 Member,which are featured by stable lateral extension,and they are dominated by fine to medium crystalline residual sand-calstic dolomite,bioclastic dolomite,and dolomitic limestone.And there exist three reservoir types,for example,dolomite porous reservoirs,dolomite fractured-vuggy and limestone porous ones;(ii)a diagenetic sequence has been es-tablished according to petrological and mineral characteristics along with contact relationship.Eight diagenetic episodes were identi-fied,including contemporaneous exposure dissolution,contemporaneous dolomitization,shalllow-burial dolomitization,shallow-burial silicification,Dongwu dolomitization,Indosinian hydrothermal dissolution,Indosinian thermal silicification,and deep-burial dissolu-tion;and(iii)for the dolomite reservoirs of Maokou Formation in the study area,both extension and distribution are jointly controlled by platform-margin high-energy beach,early exposure dissolution and dolomitization.Both later hydrothermal dissolution and burial dissolution are conducive to reforming reservoirs.
The Middle Permian Maokou Formation is one of the important gas production layers in the Sichuan Basin.Its weathered crust karst reservoirs are crucial to the production.Based on the analysis of core,logging,drilling and seismic data,the development of weathered crust karsts was characterized.Then,with the bottom surface of the second member of the Maokou Formation as the da-tum,the karst paleogeomorphology of the Formation was restored by using the residual thickness method.The karst paleogeomorpho-logical units were classified according to the modern karst theory,and the microgeomorphology and its associations in the study area.Finally,the relationships between various karst paleogeomorphical features and karst reservoirs were analyzed.The research results are as follows:(i)The top of the Maokou Formation is absent universally,and in unconformable contact with overlying strata.Various dissolution phenomena are observed,reflecting remarkable response characteristics from drilling,logging and seismic data.(ii)The karst paleogeomorphology can be divided into two second-order units:karst gentle slope and karst depression,and nine third-order units such as peak cluster depression,peak mound depression,and mound-cluster ridge ravine,etc.(iii)The karst units are very differ-ent in reservoir development conditions.Typically,the karst gentle slope has the conditions for developing large-scale karst reservoirs,especially around the negative karst topography,the dissolution and preservation conditions are excellent and high-quality karst reser-voirs are more developed.Thus,it will be the key area for subsequent exploration.
Quickly and accurately identifying source rocks through well-logging data is the main thing in source-rock evaluation.The source rocks of Middle Permian Maokou 1 Member in southeastern Sichuan Basin feature strong heterogeneity and difficulty in lith-ological identification.So,for the Maokou 1 source rocks,the logging response characteristics were clarified by using core data cali-brated with logging data.In addition,three methods such as sensitive log superposition,crossplot and ratio were employed for quali-tative source-rock identification and evaluation.Results show that(i)the logging response of quality source rocks is characterized by two-high in acoustic wave and neutron as well two-low in density and resistivity;(ii)among these three methods,superposition and crossplot are simple and easy to do in this identification,but achieving a poor effect in the other source rocks rich in shale content.However,another method of acoustic time to resistivity ratio is a rapid and effective option;and(iii)after logging-data processing and core correlation conducted for 3 wells in the study area,the qualitative source-rock identification accuracy reaches 92%by using the ratio method.
The Permian system in Sichuan Basin is complex in tectono-sedimentary evolution,creating difficulties in restoring the distribution of favorable facies zones and uncertainties in favorable exploration belts.So,through the latest 2D and 3D seismic data as well as drilling and mud-logging data in and around the basin,this evolution was investigated systematically to identify response char-acteristics and influential factors of major tectonic movements.The relationship of continuous sedimentary evolution was established to every formation and member and the distribution of favorable facies zones with multiple targets was defined to provide an import-ant support for optimizing the favorable exploration belts.After the comprehensive analysis on geological characteristics,it is revealed that(i)multiple factors,including ancient landform before the Permian deposition,and tensile tectonic setting,mantle plume uplift and volcanic eruption in the Permian,affect the tectonic-sedimentary differentiation of the Permian;(ii)representing a regional tensile tectonic setting,the Permian in Sichuan Basin was a sedimentary system of cratonic rifted basin,which controlled the distribution of bioreef-beach facies zones on the margin of multiple strata,laying a foundation for the development of massive lithologic traps;(iii)in the early Triassic,the basin inherited the sedimentary pattern in the late Permian,and exhibited one feature of filling and leveling up due to some effects,for example,ancient land,island chain and underwater uplift at the basin margin.It was a sedimentary system of cratonic depression basin,whose beaches in vertical and lateral accretion might be controlled by microgeomorphology and presented large-scale sheet-like distribution in Qingshuitai area in plane;and(iv)dependent on the analysis of tectono-sedimentary setting and the comprehensive application of 2D and 3D seismic data,the main sedimentary features were defined,such as"one margin and two ribbons"in Qixia Formation,"one uplift and one margin"in Maokou Formation,"three uplifts and three depressions"in Changxing Formation,and"three uplifting forming beaches and three depressions filling and leveling up"in Feixianguan Formation.In addition,the analysis of petroleum geology points that the main exploration domains and prospects of Permian-Triassic in Sichuan Basin will focus on the platform margin zone of Qixia Formation in western basin,the intraplatform highland zone in central-southern basin,the platform margin zone of Maokou Formation in Jian'ge-Nanchong-Shizhu area,the trough in Kaijiang-Liangping area,and the bioreef-beach on the edge of Changxing Formation in shallow shelf of Pengxi-Wusheng-Shizhu area.
In southern Sichuan Basin,an old gas base with exploration and development for more than half a century,the Permian Maokou Formation is characterized by numerous reservoir types and multiple small gas reservoirs with complex distribution.After the measurement of both homogenization temperature and salinity in fluid inclusion together with the laser Raman analysis,the inclusion development and distribution and the hydrocarbon-charging episodes in this Middle Permian Maokou Formation were figured out to determine reservoir-forming time based on petrographic characteristics.Results show that(i)this formation has experienced four charging episodes,namely,Episode I to form ancient oil reservoirs,Episode II to generate ancient oil and gas reservoirs,Episode III to grow up ancient gas reservoirs,and Episode IV to adjust gas reservoirs resulted from late tectonism;(ii)in Episode I,the homoge-nization temperature of fluid inclusion was mainly between 95℃and 113℃,suggesting the charging of liquid hydrocarbon.And the charging time should be at the end of the deposition of Xujiahe Formation,which was the forming time of ancient oil reservoirs;(iii)in Episode II,the homogenization temperature changed from 121℃to 135℃,suggesting the charging of both liquid hydrocarbon and a little gaseous hydrocarbon.And the charging time should be in the early Jurassic,which was also the forming period of ancient oil and gas reservoirs;(iv)in Episode III,the temperature ranged from 160℃to 195℃,suggesting the charging of both gaseous hydro-carbon and a little liquid hydrocarbon.And the charging time should be in the middle-late Jurassic to late Cretaceous,which was the forming time of ancient gas reservoirs;and(v)in Episode IV,the temperature was between 135℃and 160℃,apparently lower than that in Episode II,suggesting the charging of gaseous hydrocarbon.This charging has started since Neoproterozoic.And as a result of the adjustment of ancient gas reservoirs due to Himalayan tectonic uplift,Episode IV corresponds to the forming time of present gas reservoirs.
我国非常规油气资源潜力巨大:陆上中高熟页岩油资源量 283 亿吨、页岩气地质资源量 105.72 万亿立方米,其中海相页岩油气资源量 70 万亿立方米.美国致密/页岩油和页岩气可采资源量分别为 106 亿吨和 33 万亿立方米,我国致密/页岩油和页岩气可采资源量分别为55亿吨和21.8万亿立方米.页岩油气成为我国近几年的上产重点.
Most reservoirs of the Middle Permian Maokou Formation in central Sichuan Basin are extended in Maokou 2 Member.They feature complex lithology,well-developed fractures and vugs,and strong heterogeneity,leading to challenges in identifying and evaluating them and their effectiveness through well logging.Dependent on one single index of storage coefficient,the past effective-ness evaluation might create the mismatch of productivity with reservoir parameters.So,some logging data of the Maokou Formation was re-evaluated for 300-plus wells in central basin.The effectiveness as one single index with the other four factors were analyzed in-dividually,including dolomite development degree,reservoir storability and permeability,and fracture or vug development degree.Af-ter that,the indicator was constructed for reservoirs to characterize their comprehensive quality.Coupling with the thicknesses of clas-sified reservoirs,the coefficient of comprehensive quality was determined to correlate with the tested productivity.Results show that(i)because one single parameter based on logging evaluation cannot achieve an accurate effectiveness,a multi-factor model should be built for the comprehensive quality by taking lithology,storability and permeability into account;and(ii)considering that larger thick-nesses of reservoirs and Class I + II reservoirs correspond to higher tested productivity,the thickness of classified reservoirs can be combined to determine,which helps improve an accuracy to predict the productivity.By using this prediction model established,some potential reservoirs may be optimized,and one testing suggestion for old wells is also proposed.These findings effectively support not only the improvement of both reserves and production but the optimization of target zones in the Middle Permian Maokou Formation of central Sichuan Basin.
For both karst reservoirs and gas reservoirs of the Middle Permian Maokou Formation,eastern Sichuan Basin,the success-ful exploration depends on the identification of their seismic-response characteristics and patterns.The early exploration was mainly concentrated around fractured limestone karst reservoirs whereas a little study on geophysical-response characteristics of porous do-lomite reservoirs in Wolonghe area of eastern basin,impeding the supreme exploration deployment and efficient development.Thus,based on seismic and drilling data,the well-logging and well-to-seismic response characteristics were summed up for the dolomite reservoirs.Then,not only longitudinal development pattern but actual response characteristics were figured out for the dolomite res-ervoirs of Maokou Formation after forward modeling.Finally,the reservoir distribution was predicted by using seismic attribute.Re-sults show that(i)the porous dolomite reservoirs of Maokou Formation in Wolonghe area possess three-low features in terms of well logging,for example relatively low P-wave velocity,and low natural gamma and resistivity;(ii)seismically,the reservoir bottom has weak to moderate moderate peak reflection.Due to its heterogeneous extension on the plane,this bottom presents a response pattern of intermittent peak reflection laterally;and(iii)the reservoirs and favorable facies belts can be identified by means of optimized maxi-mum peak amplitude with effect.
The first member of Middle Permian Maokou Formation in Sichuan Basin was always regarded as a set of carbonate source rocks not as reservoirs for evaluation in previous exploration practices.So,XT1well,one risk exploration well,was taken as an objective to deeply figure out the natural-gas exploration potential of the first Member of Maokou Formation in eastern basin.Moreover,both mineral petrology and geochemistry were explored on the basis of core data through some methods,like physical property testing,thin section identification,and scanning electron microscope and organic geochemical analysis.Finally,characteristics as both reservoir rocks and source rocks were gained.Results show that(i)this member in eastern Sichuan Basin is dominated by medium or thin-medium layered dark-gray to gray-black argillaceous micritic bioclastic limestone and marlstone,and medium-thick to thick layered gray to dark-gray micritic bioclastic limestone and argillaceous micritic bioclastic limestone.Its depositional waterbody is relatively deep.A kind of"eyeball structure",which is formed by the interbedded micritic bioclastic limestone,argillaceous micritic bioclastic limestone and marlstone,is developed;(ii)for core plugs,their helium porosity ranges from 0.24%to 6.98%,1.39%on average,and the permeability from 0.0014 mD to 1.72 mD,0.083 mD on average,respectively,belonging to low-porosity and low-permeability reservoirs.Among which,the eyelid-shaped limestone boasts better physical properties,for example the porosity between 0.24%and 6.98%,and the reservoir space mainly consisting of sheet-like talc intercrystalline micropores and microfractures.While the eyeball limestone possesses poor storage performance with the porosity from 0.24%to 3.41%,resulting that this sort of reservoir rocks is not developed;(iii)with TOC between 0.17%and 1.63%,the eyelid limestone in this well enjoys certain hydrocarbon-generating ability.The source rocks of first Member of Maokou Formation in eastern basin are generally thicker than 80 m,thus suggesting good hydrocarbon-generating conditions;(iv)in this area,it can develop into argillaceous limestone and marlstone gas reservoirs with self-generation and self-storage as well as multiple source rocks with the favorable exploration area of 2×104 km2 and the pre-dicted resources over 2,000×108 m3,displaying large exploration prospects.
With well-developed fractures and vugs,most carbonate reservoirs in Sichuan Basin are characterized by deep burial depth and high heterogeneity.They are slightly different in wave impedance from overlying and underlying surrounding rocks,making it impossible to generate strong reflector exhibiting intermittent and low-energy reflected properties.As a result,their seismic response is more feeble.So,considering original seismic data with weak reflected signals and severe frequency attenuation,four technologies were studied for weak reflected-signal processing in deep carbonate,including fidelity denoising of signals as well as amplitude and frequency restoration and post-stack processing of weak signals.Results show that(i)feeble reflected signals in Permian reservoirs can be well protected by using the fidelity denoising;(ii)adopting formation velocity gained from seismic processing,these weak re-flected loss signals of reservoirs are recovered effectively through the Q data calculated by the empirical formula and the Q absorption compensation of wave equation;and(iii)wavelet shaping and fidelity frequency expansion can be conducted for newly stacking data-base via dominant-gather stacking after migration,which gives prominence to the seismic response of Permian reservoirs.The success rate of reservoir prediction up to 89%has been achieved after the application of these processing technologies to the Permian Maokou Formation in Shehong and Xichong areas.
The Middle Permian Maokou Formation has always been a hot spot in Sichuan Basin for oil and gas exploration since natural-gas discovery in the 1950s.With the increasing development,the dolomitized beach reservoirs of this formation in central ba-sin have been undoubtedly the most effective exploration target in recent years.So,large amount of reexamination on old wells and seismic-data interpretation were conducted for eastern basin with a little exploration in order to find out other areas with dolomitized reservoirs of the Maokou Formation.Results show that(i)carbonate rocks in the Maokou Formation,eastern Sichuan Basin,are most-ly transformed into siliceous rocks of the Gufeng Member,while dolomitized beach reservoirs have been newly found in the Maokou Formation beneath the siliceous rocks in Xuanhan-Wanxian area;(ii)microscopic observation displays the dolomitized reservoirs prin-cipally being fine to silty crystal dolomite with strong dolomitization.Vertically,the reservoirs are mainly developed at the bottom of Maokou 2 Member,with the logging porosity of 3.5%-4.3%and the thickness of 3-12 m,indicating better reservoir properties;and(iii)for them,the planar-distribution prediction implies the largest thickness in Wubaiti area to the east Kaijiang,over 15 m in some areas.And favorable exploration areas with the dolomitized beach reservoirs of Maokou Formation thicker than 6 m beneath siliceous rocks in eastern basin are approximately 3,900 km².These areas are expected to become new battlefields for increasing reserves and produc-tion in eastern Sichuan Basin.
Gas reservoirs of the Middle Permian Maokou Formation,Longnvsi-Hechuan area,Sichuan Basin,have achieved signifi-cant exploration discoveries,making them the best domain for the future breakthrough across trillions of cubic meters.There majorly developed dolomite reservoirs of intra-platform shoal facies in this formation,which extend along the edge of paleo-uplift with large-scale resources and great exploration prospects.However,Maokou reservoirs exhibit complex spatial distribution and poor physi-cal properties due to deep burial depth and various karstification,resulting in difficult fine interpretation of interlayers,ambiguous seismic-response characteristics,and challenges in reservoir prediction.For purpose of reservoir prediction and description on key parameters to support the exploration and development in this area,both ancient landform and favorable facies of the Maokou Forma-tion were predicted by using the technology of"structural interpretation with high precision and ancient-landform characterization"and based on interlayer interpretation.Additionally,through inversion of facies-controlled dolomite reservoirs,the spatial distribution of reservoirs was determined to facilitate the delineation of favorable intra-platform shoal zones in this Maokou Formation.Results show that the technology of facies-controlled thin dolomite reservoir prediction may effectively reflect the spatial distribution,laying a foundation for predicting the dolomite reservoirs to support well deployment and exploration and development practices in central Sichuan Basin.
An important breakthrough has been made in carbonate reservoirs of evaporate-platform lagoon facies through the explora-tion on the Middle Triassic Leikoupo Formation in central Sichuan Basin,which reveals a new prospective target,namely the second submember of the third member of Leikoupo Formation(Lei32 submember).So,through core and cuttings analysis,thin-section obser-vation,and well-to-seismic analysis,the main influential factors and prospects were figured out for calcareous reservoirs of this sub-member in central basin.Results show that(i)these Lei32 reservoirs are mainly composed of argillaceous limestone and limy mudstone developed with nano-to micron-sized inorganic pores,organic pores and microfractures;(ii)there is high porosity in some reservoirs with rich clay mineral or coexistence with gypsum,and the permeability is improved by fractures with effect;(iii)for this submember,the seismic facies were divided by using the thickness of gypsum-salt rock,and the crumple deformation zone was predicted by the thickness from Jialingjiang 4 to Jialingjiang 5 members.With an area of 4,000 km2,Xichong-Yingshan area featuring the overlap of aforementioned seismic facies and deformation zone is a favorable belt to develop with calcareous reservoirs;and(iv)the calcareous reservoirs can form massive self-generating and self-preserving unconventional reservoirs with gypsum-salt rock as the seal,and they will certainly be the realistic domain for oil and gas exploration in the Leikoupo Formation of Sichuan Basin.
The Upper Permian Wujiaping Formation in Sichuan Basin exhibits varying sedimentary facies laterally,and there develops a set of marine black shale in the northern Basin.Taking Well Fengtan 1 in northeastern Sichuan Basin as an example,the geological conditions for shale gas were studied by petrological,geochemical,scanning electron microscopy,low-temperature nitrogen adsorption and methane adsorp-tion methods.The results are as follows:(i)Two sets of black shale are developed in the Formation in the syudy area.One is in the second mem-ber of Wujiaping Formation(Wu 2 Member),consisting of grayish black to black clay shales of shore-side tidal flat facies,with low brittleness index and weak fracturability.The other is in the third member(Wu 3 Member),consisting of black siliceous and calcareous shales of deepwater shelf facies,with high brittleness index and strong fracturability.(ii)The Wu 2 Member shales have the average TOC of 1.41%,of which the black shale is relatively thin,with TOC>2%and Type III organic matters.The Wu 3 Member shales have the average TOC of 3.52%,of which the black shale is 26 m in thick,with TOC>2%and Type II1-II2 organic matters.Both sets are in the over-mature stage.(iii)The Wu 2 Member shales have the reservoir spaces mainly consisting of intergranular pores in clay minerals and microfractures,with relatively underdeveloped or-ganic pores.The reservoir pores are dominated by mesopores,followed by micropores,with a volume of 0.006 6 cm3/g and a gas content of 1.519 0 cm3/g.The Wu 3 Member shales have the reservoir spaces mainly consisting of organic pores,which are dominated by micropores,followed by mesopores,with an average volume of 0.014 1 cm3/g and an average gas content of 2.307 0 cm3/g.The pore structure and gas content are controlled significantly by the organic matter abundance,but not obviously by the mineral composition.(iv)The Wu 2 Member shales demon-strate relatively poor geological conditions and weak exploration potential.In contrast,the Wu 3 Member shales have favorable conditions and also good gas potential,with superior gas content and organic matter abundance to the Lower Silurian Longmaxi Formation.
高产水、低产气是煤层气生产过程中常见的一种现象,查明煤层气井高产水原因、确定产水来源一直是行业性难题.为此,以柿庄南区块 3 号煤层高产水井为例,根据测井、录井、微地震监测及生产数据,运用排除法找到了该区高产水井产水高的原因,通过同位素示踪、产水量和含水层发育特征相关性分析等技术手段,弄清了高产水井的产水来源.分析结果表明:①断层和压裂缝沟通含水层是该区煤层气井高产水的主要原因;②断层沟通含水层型高产水井产出水主要为来自于上石炭统太原组及奥陶系的石灰岩岩溶水;③压裂缝沟通含水层型高产水井产出水主要来源于下二叠统山西组底部的K7 砂岩.
为查明川西北部地区是否发育完整的寒武系—奥陶系的地层格架,以赋予该地区地震资料新提出的德阳—绵阳拗陷地质意义以及支撑厘清该地区构造—沉积演化过程,从而更加精准服务于油气的风险勘探部署工作.利用野外剖面精测以及锆石U-Pb同位素定年分析等手段对川西北部地区多个寒武系—奥陶系剖面的岩石类型、沉积序列以及年代归属等进行了研究.研究结果表明:①川西北部地区原定义的"筇竹寺组"顶部最大沉积年龄峰值约为 505 Ma,磨刀垭组最大沉积年龄约为 479 Ma;前者限定了筇竹寺组顶部的沉积时限晚于芙蓉世,后者限定了其沉积时限晚于中奥陶世.综合表明研究区可能发育连续的寒武系—奥陶系,并非缺失中上寒武统—中下奥陶统.②川西北地区寒武纪—奥陶纪时期发育潮坪→浅水陆棚→滨岸→三角洲→碳酸盐岩台地沉积环境,经历了细粒碎屑岩→粗碎屑岩→碳酸盐岩的沉积充填过程.③沉积环境可能受到加里东期的郁南、都匀、广西等多幕次构造运动的影响.④研究结果不仅为前人新提出的该地区发育寒武纪—奥陶纪局部拗陷提供地质证据,而且为四川盆地西北缘构造—沉积格局的进一步厘定奠定了基础.
