通过系统分析四川盆地中部地区（川中地区）大安寨段致密油的基本地质特征,结合大量勘探开发数据,解剖致密油高产稳产主控因素及勘探方向。大安寨段致密油具有如下特征：资源量大,丰度低;储集层总体致密,发育相对优质储集层;源储一体（或紧邻）,油气运聚有利;不同类型孔隙普遍含油,连续分布。开发实践揭示,致密油高产稳产井主要分布在滨湖沉积亚相中的裂缝-孔洞型储集层中,裂缝在大安寨段致密油高产稳产影响因素中至关重要,天然气在石油运聚以及油井的高产中起到了重要驱动（气驱）作用。结合高产稳产特征、勘探开发成效以及钻井投资成本等因素综合评价认为,川中南部地区的大安寨段为四川盆地侏罗系致密油效益勘探开发的现实领域。图7表5参18

By systematically analyzing the basic geological characteristics of tight oil in Jurassic Da’anzhai Member in the middle of Sichuan Basin (Central Sichuan area) and combining with a large number of exploration and development data, we examine the main controlling factors and exploration direction for high and stable production of tight oil. Tight oil in the Da’anzhai Member has the following characteristics: large and low abundance resources; generally tight, relatively high quality reservoirs; adjacent source rocks and reservoirs, favorable migration and accumulation of oil; extensive oil-bearing pores. Development practice reveals that the high and stable production oil wells for tight oil are mainly distributed in fractured vuggy reservoirs in the shore-lacustrine sedimentary subfacies, and fractures are very important in affecting the high and stable production of tight oil in the Da'anzhai Member. Natural gas plays an important role (gas drive) in petroleum migration and accumulation and high production of oil wells. Combined with the characteristics of high and stable production, exploration and development results, drilling cost and other factors, it is considered that the Da’anzhai Member located in the middle and south part of Sichuan Basin is a promising field for exploration and development of tight oil in the Jurassic of the Sichuan Basin.

油气勘探开发领域从常规油气向非常规油气跨越，是石油工业发展的必然趋势，二者在油气类型、地质特征及聚集机理等方面明显不同。常规油气研究的灵魂是成藏，目标是回答圈闭是否有油气；非常规油气研究的灵魂是储层，目标是回答储集有多少油气。非常规油气主要表现在连续分布、无自然工业产量。目前，常规油气面临非常规的问题，非常规需要发展成新的“常规”。伴随技术的进步，非常规可向常规转化。常规油气聚集包括构造油气藏、岩性-地层油气藏，油气以孤立的单体式或较大范围的集群式展布，圈闭界限明显，储集体发育毫米级—微米级孔喉系统，浮力成藏。非常规油气聚集包括致密砂岩油和气、致密碳酸盐岩油和气、页岩油和气等，一般源储共生，大面积连续或准连续分布于盆地斜坡或中心，圈闭界限不明显，页岩系统储集体广泛发育纳米级孔喉，浮力作用受限，油气以原位滞留或短距离运移为主。以中国重点盆地致密油和致密气为例，系统分析了其地质特征与勘探潜力。非常规油气储集空间主体为纳米级孔喉系统，局部发育微米—毫米级孔隙，其中页岩气储层孔径为5～200 nm，致密灰岩油储层孔径为40～500 nm，致密砂岩油储层孔径为50～900 nm，致密砂岩气储层孔径为40～700 nm。针对全球石油工业和纳米等技术的快速发展，提出了“纳米油气”的概念，指出“纳米油气”是未来石油工业的发展方向，需要发展纳米油气透视观测镜、纳米油气驱替剂、纳米油气开采机器人等换代技术，油气智能化时代将随之到来。

通过对四川盆地侏罗系石油的资源潜力、油藏类型、裂缝型储层及勘探开发技术适应性等4个方面进行的再认识，作者认为：①四川盆地侏罗系的石油资源量可能比目前的（10~11）×10⁸t 要大得多。②它是一种特殊类型的大面积非常规致密油聚集，没有明显圈闭界限；没有明显边、底水及油水界面，属“无水油藏”；浮力与重力分异不明显，缺少大规模二次运移，源内或近源聚集；储层具有特低孔渗、双重介质特征；大面积整体含油，多层系叠合连片，“连续”分布在斜坡及凹陷区，不受局部构造控制而受岩性控制，含油范围以油井分布范围划定，往往是先有产量后有储量。③不能把侏罗系油层简单定性为“裂缝型”，裂缝是测试及生产初期获得高产的必要条件，但各类孔隙对储量和长期低产稳产有重要贡献。④这类非常规致密油的储量规模很大，但是要采用以压裂为主的非常规技术进行开采。建议以龙岗地区沙溪庙组为突破口，推动四川盆地石油勘探开发打开一个新局面。

<p>The present paper made a re-recognition of Jurassic oils in Sichuan in terms of the four aspects, such as resource potential, reservoir types, fractured reservoirs and techniques of exploration and development. The paper has drawn the following conclusions. ①The Jurassic oil resource in Sichuan may be much more than the presently discovered amount of 1.0~ 1.1 billion tons.②The Jurassic oil resource is a special large-area and non-conventional compact oil accumulation that has no clear trap boundaries, no clear edge-water, bottom-water and oil-water boundaries like a &ldquo;water-free reservoir&rdquo;, and no clear differentiation between buoyancy and gravity. Their reservoirs are characterized by inner-source or near-source accumulation rather than large-scale secondary migration, ultra-low permeability, dual media, large-area entire oiliness, superimposed and linked multi-measures, &ldquo;continuous&rdquo; occurrence on slopes or in depressed areas, being restricted by lithology rather than local structures, and delimitating oil-bearing and well distribution areas frequently by output instead of reserve.③Jurassic reservoirs can not be simply defined as &ldquo;fractured type&rdquo; because various pores contribute significantly to both the reserves and long-term low but stable production though fractures are the prerequisite for a high output at the testing or production beginning. ④These exists a great reserve for this kind of non-conventional compact oils in the central-northern Sichuan, however, a non-conventional technique consisting mainly of hydraulic fracturing should be adopted in development. It was proposed that Shaximiao Formation in the Longgang area should be a prospecting target, which will be a breakthrough to open a new era for petroleum exploration in Sichuan Basin.</p>

致密油的分布呈现大面积低丰度含油背景下局部富集的特征，亦只有在富集区内才能获得可观的商业油流。因此，甜点区的优选是致密油地质研究的重点。为分析致密油的富集规律，服务致密油甜点评价，以四川盆地侏罗系大安寨段为例，依托油田详实的生产数据，运用成藏物理模拟实验、显微薄片、场发射扫描电镜资料，并结合综合地质成图，对致密油的富集主控因素进行了研究。结果表明，研究区致密油的富集具有强烈的非均质性，占总井数22.5%的高产井产出了84.4%的油气，致密油富集程度的差异在盆地和区带尺度的分布上持续存在，并分别受不同因素的差异化控制。在盆地尺度下，受二次运移的影响，烃源岩只能控制致密油的分布外边界，在有利烃源岩区内部无法严格约束甜点区分布。在区带尺度下，有利沉积相带控制了致密油富集区带的分布。致密油富集甜点受有利成岩相和裂缝的控制。基于上述认识，建立了一套致密油富集甜点评价参数体系，为致密油甜点选区提供支持。

The tight oil is characterized by large scale distribution with low abundance, and accumulating in local areas. Only in enrichment regions, commercial oil production can be acquired. Thus, the evaluation of sweet spot is the key work of geological research of tight oil. Da′anzhai member in Sichuan Basin was taken as an example to study the accumulation pattern of tight oil, to serve the sweet spot evaluation of tight oil. Based on the large amount of production data from the oil field, accumulation physical analog experiment, thin sections, and Field Emission Scanning Electron Microscope (FESEM) were utilized to research the main controlling factors on tight oil accumulation, combined with the geologic mapping. According to the study, the accumulation and distribution pattern of tight oil shows a severe heterogeneity in the study area. High production wells, 22.5% of all wells, produced 84.4% hydrocarbon in all production of the study area. This heterogeneity continuously exists both in basin and play scales. In different scales, the accumulation was controlled by different factors. In basin scale, due to the secondary migration, source rock could only control the distribution boundary of tight oil, and was unable to control the distribution of favorable play within the source rock area. In play scale, favorable sedimentary facies controlled the distribution of tight oil accumulation area. The final tight oil accumulation sweet spots were controlled by the favorable diagenesis facies and fractures. Based on the study, a set of evaluation parameters for the tight oil accumulation sweet spot was established to support the profitable area evaluation.

四川盆地侏罗系发育3套半深湖亚相富有机质页岩，具有叠置发育、广覆分布的特征，半深湖亚相页岩具有"高TOC、高孔隙度、高含气量"的特点。四川盆地侏罗系多口井、多个层段的陆相页岩油气近期取得勘探新突破，勘探潜力巨大、资源丰富，是继五峰组—龙马溪组海相页岩气之后的重点资源接替领域。经过细粒岩综合评价研究发现其具有强非均质性，通过建立"四元"岩相划分方案，明确了陆相页岩油气富集高产主控因素：半深湖亚相富有机质页岩提供了物质基础、良好的构造保存及高压条件是关键、适宜的热演化程度及微裂缝发育有利于油气富集及烃类流动、地质—工程一体化研究是高产的保障。侏罗系陆相页岩油气资源潜力大、天然气当量为6.0×10¹²m³，占四川盆地天然气总资源量的27.7%，是"十四五"（2021—2025年）期间增储上产的重要领域。川东北地区多层页岩叠置发育、川南地区半深湖亚相页岩大面积展布，是重要的勘探有利区，其中，中国石油化工集团有限公司所属矿权区的天然气总资源量为2.94×10¹²m³、原油为12.03×10⁸t，是西南地区油气勘探开发的重要资源接替阵地。四川盆地陆相页岩油气勘探开发仍处于初期，在细粒岩沉积储层、油气藏性质、富集高产主控因素、适应性的工程压裂改造技术等多方面仍存在不足，尚需加大科技攻关及深入实践，力争实现"十四五"期间四川盆地陆相页岩油气的更大突破及规模性增储上产。

Three sets of bathyal lacustrine organic-rich shale are developed in the Jurassic of Sichuan Basin, characterized by superposed development and broad distribution; the bathyal lacustrine shale is characterized by "high TOC, high porosity and high gas content". Recently, new breakthroughs have been made in the exploration of continental shale oil and gas in multiple wells and sections of the Jurassic in Sichuan Basin, boasting of great exploration potential and abundant resources, which are key replacement resources instead of the marine shale gas in Wufeng Formation and Longmaxi Formation. Through comprehensive evaluation of fine-grained rocks, it is found that the continental shale oil and gas have strong heterogeneity. On this basis, a quaternary lithofacies division scheme was established to clarify the main controlling factors for the enrichment and high production of continental shale oil and gas. Specifically, the bathyal lacustrine organic-rich shale provides the material base, good tectonic preservation and high-pressure conditions are the key conditions, appropriate thermal evolution and microfracture development are conducive to hydrocarbon enrichment and flow, and the geology-engineering integrated research can guarantee high production. The Jurassic continental shale oil and gas resources have great potential, with the natural gas equivalent of 6.0×10¹²m³, accounting for 27.7% of the total natural gas resources in Sichuan Basin. This is an important field for increasing reserves and production during the "14th Five-Year Plan" period (2021-2025). Multilayer superimposed shale is developed and bathyal lacustrine shale distributes extensively in northeastern Sichuan, which are important favorable zones for exploration. Sinopec has the total natural gas resources of 2.94 × 10¹²m³ and crude oil of 12.03×10⁸ t in these areas, which are important replacement resource fields for oil-gas exploration and development in Southwest China. The exploration and development of continental shale oil and gas in Sichuan Basin is still in the early stage, and there are still deficiencies in research of fine-grained rock sedimentary reservoirs, reservoir properties, main controlling factors of enrichment and high production, and applicable engineering fracturing technology. It is still necessary to make more efforts to tackle key scientific and technical problems and practice deeply, and strive to achieve greater breakthroughs in the exploitation of continental shale oil and gas in Sichuan Basin during the "14th Five-Year Plan" period and increase reserves and production on a large scale.

随着认识的不断深入和工程技术的进步，页岩油气已经正式进入我国储量序列，正在有序开发。通过岩心、露头、钻井、测井以及大量的分析化验资料，对四川盆地侏罗系大安寨段湖相页岩油气的形成地质条件和资源潜力进行系统分析和评价。研究结果表明：①大安寨段湖相页岩主要发育在大一三亚段浅湖、半深湖泥，有机碳含量平均为1.15%，有机质类型均以Ⅱ型干酪根为主，镜质体反射率介于0.8% ～ 1.4%，处于成熟—高成熟阶段，页岩厚度大，生烃能力强，具备形成页岩油气的物质基础。②大安寨段页岩以黑色、灰黑色页岩与生物介壳灰岩不等厚互层为主，脆性矿物平均含量为63.4% 含量较高；页岩孔隙度平均为5.92%，储集条件好，储层发育微米- 纳米级孔隙，具备储集页岩油气的储集空间，有利于页岩储层的改造。③大安寨段湖相页岩油气具有埋藏浅、保存条件好、压力系数高等优越条件，按照有机碳含量TOC>1.5% 的范围，计算页岩油资源量为70×108 t，页岩气的资源量为3.5×1012 m3 ，结合大安寨段页岩油气评价指标，优选出射洪—遂宁—南充—蓬安—仪陇—南部页岩油气勘探有利区近1×104 km2 ，并建议在公山庙、龙岗地区开展先导试验工作。

可动页岩油综合定量评价是优选研究区有利区块、有利层段、有利岩性组合的基本依据,侏罗系页岩油是四川盆地当前勘探的重点层系,但对其大安寨段页岩油可动性的综合评价和可采层段预测还未见报道。以大安寨段储层为研究对象,通过扫描电镜、低温氮气吸附等微观实验手段,研究不同岩性组合的储集空间、赋存机理及孔隙结构特征;在烃源岩特征基础上,分析大安寨段储层的含油性和吸附差异性;根据基础含油性分析,进一步通过动态岩心实验深入分析目标储层的可动性,并明确其可动性影响因素;最后,通过可动性影响因素分析,依据模糊层次分析法、和积法、平移极差变换法,建立了大安寨段页岩油可动性综合评价指标体系和综合量化方法,筛选了页岩油可动性主要影响因素,优选了大安寨段有利岩性组合,并预测了相应的有利开采层段和可动资源量,通过勘探突破井获得了证实。研究结果表明:大安寨段介壳灰岩致密、泥页岩微裂缝欠发育,含油性最好的纹层状灰质介壳页岩的OSI(即热解游离烃量S₁与有机碳含量的比值)可达121.86 mg/g,页岩油可动性最好的是不等厚泥页岩与介壳灰岩互层,其采油指数达34 mg/g。因此,大安寨段可开采的页岩油为互层型/夹层型岩性组合页岩油,致密介壳灰岩顶底板间夹层频率高的大安寨段一亚段下部和大安寨段二a亚段上部、以及大安寨段二b亚段为预测可开采层段,平面上分布在南充—阆中—仪陇—平昌一带、涪陵和三台地区,Ⅰ类有利区页岩凝析油可动资源为1.91×10⁸t、凝析气可动资源为3 232.39×10⁸m³,具有良好的前景。

四川盆地侏罗系大安寨段为典型的淡水湖相沉积，前期评价致密油资源量高达9&times;10⁸t，展示出巨大的勘探开发前景。在烃源岩、储层特征分析的基础上，结合大量的生产动态数据，重点解剖了淡水湖相沉积区源储配置关系对致密油富集区的控制作用。通过解剖表明，淡水湖相沉积区源储配置关系受沉积微相控制，可以划分为厚储下薄源上、厚储上薄源下、厚储夹厚源、薄储夹厚源以及源储侧向接触5种类型。实验模拟表明，源储空间配置关系是控制致密油富集程度的关键。典型油田勘探开发实践揭示，滨湖沉积相带下的厚储下薄源上配置类型最好，浅湖沉积相带下的厚储夹厚源配置类型其次，半深湖沉积相带下的薄储夹厚源配置类型相对较差。根据上述源储配置模式和目前的勘探开发实践情况可以得出，滨湖沉积相带是致密油的现实勘探区域，半深湖沉积相带是页岩油气的勘探区域。这一认识可以为四川盆地侏罗系大安寨段致密油、页岩油气的勘探开发评价提供一定依据。

In order to reveal the characteristics of nonmarine organic-rich formations and the productivity of different types of stratigraphic structure sections, taking the Da&rsquo;anzhai member of Jurassic Ziliujing Formation and the fifth member of Triassic Xujiahe Formation in Sichuan Basin as examples, this paper divided the statigraphic structure section by making the ratio of shale to gross and thickness of single sand （limestone） as standards based on the field observed profiles, drilling data and sedimentary settings, and compared with the structure sections of Bakken Formation in North America. The nonmarine organic-rich stratigraphic structure sections were divided into five types: tight sandstone （limestone）, sandstone-rich （limestone-rich） with shale, sandstone （limestone） and shale interbed, shale-rich with sandstone （limestone） and shale. The tight sandstone （limestone） oil and gas coexist with shale oil and gas in nonmarine organic-rich formations, and the shale oil and gas are mainly produced in the last three types of structure sections. There are multiple productive targets in nonmarine organic-rich formations, so, it is proposed that the formation of organic-rich shale interbedded with limestone or sandstone should be considered to explore as a whole.

川东地区侏罗系自流井组大安寨段具有“近源成藏”特征。通过烃源岩评价、流体包裹体分析、埋藏史恢复等方法，对川东地区侏罗系自流井组大安寨段储层特征与油气成藏进行了研究。研究结果表明: ①川东地区侏罗系自流井组大安寨段泥页岩有机质类型主要为Ⅱ型，实测残余有机碳质量分数平均为0.67%，生烃潜量为1.53mg/g，有机质热演化程度为1.1%～1.3%，总体上，大安寨段烃源岩有机质丰度中等偏下，处于生烃高峰期。②研究区大一亚段岩性以介壳灰岩和灰岩为主，构造缝为最主要的储集空间类型，其次为沿构造缝发育的溶孔(洞)、溶蚀微孔，储层物性较差，为特低孔特低渗储层。③研究区大安寨段油气藏存在2期原油充注和1期天然气充注，2期原油充注时间分别为距今约140Ma和25Ma，其中第一期为相对低成熟度的原油充注，第二期为相对高成熟度的原油充注，且后者为主要充注期，天然气充注时间与第二期原油充注时间一致，主要为原油伴生气。

The Da’anzhai member of Jurassic Ziliujing Formation in eastern Sichuan Basin has the typical characteristics of near-source hydrocarbon accumulation. By means of source rock evaluation，fluid inclusion analysis and burial history recovery，the reservoir characteristics and hydrocarbon accumulation of Da’anzhai member of Jurassic Ziliujing Formation in eastern Sichuan were studied. The results show that: (1) The organic matters of Da’anzhai member of Jurassic Ziliujing Formation in eastern Sichuan Basin are mainly type Ⅱ. The measured residual organic carbon mass fraction is 0.67%，the hydrocarbon generation potential is 1.53 mg/g，and the thermal evolution degree of organic matter is 1.1%-1.3%. On the whole，the source rocks of Da’anzhai member have medium to low abundance of organic matters，which is at the peak of hydrocarbon generation. (2) The lithologies of the first submember of Da’anzhai member in the study area are mainly shell limestone and limestone，and the structural fractures are the main reservoir space，followed by dissolved pores (caves) and dissolved micropores developed along the structural fracture. The reservoirs have poor physical properties with ultra-low porosity and ultra-low permeability. (3) There are two stages of crude oil charging and one stage of natural gas charging in the reservoirs of Da’anzhai member in the study area. The two stages of crude oil charging time are about 140 Ma and 25 Ma respectively. The first stage is relatively low maturity crude oil charging，the second stage is relatively high maturity crude oil charging，and the latter is the main charging period. The natural gas charging time is the same as the second stage of crude oil charging，which is mainly associated gas of crude oil.

在致密灰岩储层特征认识的基础上，利用薄片鉴定、测井响应、叠前地震波形指示反演（SMI）等方法对四川盆地公山庙西地区大安寨段致密灰岩储层特征及高产主控因素展开了详细研究。研究结果表明：①四川盆地公山庙西地区大安寨段灰岩储层可分为厚层型和薄层型2种类型。灰岩储层平均孔隙度为1.2%，平均渗透率为0.05 mD，为特低孔、低渗储层，储集空间主要为次生溶孔和微裂缝；②根据断层规模、断穿层位及平面上的断距，将研究区断层分为一级、二级和三级，其中大安寨段主要受一级和二级断层影响，与断层伴生的裂缝体系有效改善了储层物性；③研究区有利相带控制了油气的分布，断储配置关系控制了油藏的产能，可分为“薄层灰岩+一级断缝”与“厚层灰岩+一级/二级断缝”2种高产模式。

On the basis of the understanding of the characteristics of tight limestone reservoirs in the Da’anzhai Formation in the western area of Gongshanmiao of Sichuan Basin，the development scale of the fracture system was identified and graded by using the methods of thin section identification，logging response，and SMI And the main controlling factors of tight oil and high yield in the Da’anzhai Member were studied. The results show that：（1）The limestone of the Da’anzhai section is divided into two types of reservoirs：thick-bedded limestone and thin-bedded limestone. The limestone reservoir has an average porosity of 1.2% and an average permeability of 0.05&#215;10^-3 μm²，which is a very low porosity and low permeability reservoir，and dissolution is an important factor in the formation of reservoir properties，and the reservoir space is mainly secondary dissolved pores and micro-fractures.（2）According to the size of the fault，the fault layer and the fault distance on the plane，the fault is divided into primary，secondary and tertiary. Among them，the Da’anzhai section is mainly affected by the primary and secondary faults，the fractures associated with faults can effectively improve the physical proper ties of the reservoir.（3）It is concluded that favorable facis development and t relationship of fault-reservoir con figuration are the control factor to determine the high yield of the reservoir. There are two high-yield models： “thin limestone first-level fracture”and“thick limestone first-level/second-level fracture”.

通常地层压实背景趋势是直接通过井上趋势拟合得到，往往存在较大的误差，导致地层压力预测不准。四川盆地渝西区块深层页岩气勘探开发有利区的储层中普遍存在地层超压现象，常规的地层压力地震预测方法难以准确地获取地层压实背景趋势。通过实际测井分析，基于岩石物理理论，利用岩石物理模型构建了地层压实背景趋势，有效提高了地层压实背景趋势的建模精度。将岩石物理建模构建的正常压实背景趋势与实测参数代入体积模量方程中，实现了渝西区块地层压力的地震预测。对比结果表明，预测的地层压力参数与多口井的地层压力实测参数较为吻合，取得了良好的应用效果。

Seismic prediction of formation pressure is of great significance to the evaluation of powerful gas-producing areas and exploration and development of shale oil and gas reservoirs. The study area of western Chongqing is a favorable area for exploration and development of deep shale gas. The shale gas resources in the area are abundant, and formation overpressure is common in the reservoirs. However, due to complex geological conditions, it is difficult to accurately obtain the formation compaction background trend while using conventional formation pressure seismic prediction methods, making it difficult to properly solve the seismic prediction of formation pressure. Usually, the formation compaction background trend is obtained directly through well trend fitting. The established formation compaction background often has large errors, resulting in inaccurate formation pressure prediction. Therefore, this paper constructs the formation compaction background trend through actual logging analysis, based on rock physics theory and rock physics model, which effectively improves the modeling accuracy of formation compaction background trend. By substituting the normal compaction background trend and measured parameters constructed by petrophysical modeling into the bulk modulus equation, the seismic prediction of formation pressure of the study area of western Chongqing in the Sichuan Basin is achieved, and good application results are achieved. By comparing with the actual drilling measured results, it is found that the predicted formation pressure parameters are consistent with the measured formation pressure parameters of multiple wells, indicating the applicability and accuracy of the method.