Geological and Engineering‘Sweet Spots'in the Permian Lucaogou Formation,Jimusar Sag,Junggar Basin

Unconventional oil and gas resources require petrophysical logs to answer the question of how best to optimize geological and engineering‘sweet spots'.Therefore,the establishment of a key well with comprehensive descriptions of lithology,reservoir properties,hydrocarbon-bearing properties,electronic well log responses,source rock properties,brittleness,and in situ stress magnitude and direction is important for the effective exploration and production of unconventional hydrocarbon resources.Cores,thin sections,scanning electron microscopy(SEM)and comprehensive well log suites are used to build a key well for the Permian Lucaogou Formation,Jimusar Sag of the Junggar Basin.The results show that there are three main types of lithologies,including siltstone,mudstone and dolostone.Lithologies can be predicted using the combination of conventional well and image logs.The pore spaces consist of interparticle pores,intragranular dissolution pores and micropores.Nuclear Magnetic Resonance(NMR)T_(2)components longer than 1.7 ms are superposed as effective porosity.Permeability is calculated using the Coates model from NMR T_(2)spectra.The ratio of T_(2)components>7.0 ms to T_(2)components>0.3 ms is used to calculate oil saturation.TOC is calculated using theΔlog R method.Brittleness index is calculated using Poisson-Young's method,ranging from 13.42%-70.53%.In situ stress direction is determined,and in situ stress magnitudes(maximum horizontal stress SH_(max),minimum horizontal stress Sh_(min),vertical stress S_(v))are calculated using density and sonic logs.The strike-slip stress type(SH_(max)>S_(v)>Sh_(min))is encountered.The key well which comprehensively includes the above seven properties is established.Geological and engineering(geomechanical)‘sweet spots'are then optimized from the key well by fully analyzing lithology,reservoir property,oilbearing potential,in situ stress magnitude and brittleness.It is hoped that the results support engineers'and geologists'decisions for the future exploitation of unconventional hydrocarbon resources.

Genesis of granular calcite in lacustrine fine-grained sedimentary rocks and its indication to volcanichydrothermal events: A case study of Permian Lucaogou Formation in Jimusar Sag, Junggar Basin, NW China

Granular calcite is an authigenic mineral in fine-grained sedimentary rocks.Core observation,thin section observation,cathodoluminescence analysis,fluid inclusion analysis,scanning electron microscope(SEM),and isotopic composition analysis were combined to clarify the genesis of granular calcite in the lacustrine fine-grained sedimentary rocks of the Permian Lucaogou Formation in the Jimusar Sag,Junggar Basin.It is found that the granular calcite is distributed with laminated characteristics in fine-grained sedimentary rocks in tuffite zones(or the transitional zone between tuffite and micritic dolomite).Granular calcite has obvious cathodoluminesence band,and it can be divided into three stages.Stage-Ⅰ calcite,with non-luminesence,high content of Sr element,inclusions containing Cos,and homogenization temperature higher than 170℃,was directly formed from the volcanic-hydrothermal deposition.Stage-Ⅱ calcite,with bright yellow luminescence,high contents of Fe,Mn and Mg,enrichment of light rare earth elements(LREEs),and high homogenization temperature,was formed by recrystallization of calcareous edges from exhalative hydrothermal deposition.Stage-IlI calcite,with dark orange luminescence band,high contents of Mg,P,V and other elements,no obvious fractionation among LREEs,and low homogenization temperature,was originated from diagenetic transformation during burial.The granular calcite appears regularly in the vertical direction and its formation temperature decreases from the center to the margin of particles,providing direct evidences for volcanic-hydrothermal events during the deposition of the Lucaogou Formation.The volcanic-hydrothermal event was conducive to the enrichment of organic matters in fine-grained sedimentary rocks of the Lucaogrou Formation,and positive to the development of high-quality source rocks.The volcanic-hydrothermal sediments might generate intergranular pores/fractures during the evolution,creating conditions for the self-generation and self-storage of shale oil.

Organic-rich rocks;Paleoenvironment;Lucaogou Formation;Jimusar Sag;Junggar Basin

The Lucaogou Formation in the Jimusar Sag of the eastern Junggar Basin is an important sedimentary stratum accumulating huge amounts of lacustrine tight oil in China, where organic-rich rocks are commonly observed. Focusing on the Lucaogou Formation, a precise analysis of the inorganic and organic petrology and the inorganic geochemistry characteristics was conducted. The paleoclimate and paleoenvironment during sedimentation of the Lucaogou Formation were established,and the key factors that were controlling the accumulation of organic matter during this time were identified. The results of this study suggest that during the sedimentation of the Lucaogou Formation, the paleoclimate periodically changed from a humid environment to an arid environment. As a result, the salinity of the water and the redox environment fluctuated.During the sedimentation period, the lake showed su cient nutrient supplies and a high primary productivity. The interval studies in the Lucaogou Formation were divided into five sedimentary cycles, where the first, second, and fifth sedimentary cycles consisted of cyclical paleoclimate fluctuations varied from a humid environment to an arid environment and shifted back to a humid environment with levels of salinity from low to high and decreased again. The third and fourth cycles have cyclical fluctuations from a humid to an arid environment and corresponding salinity variation between low and high levels.During the period when organic-rich rocks in the Lucaogou Formation deposited in the Jimusar Sag, the paleoclimate and the water body were suitable for lower aquatic organisms to flourish. As a result, its paleoproductivity was high, especially during the early period of each cycle. A quiet deep water body is likely to form an anoxic environment at the bottom and is also good for accumulation and preservation of organisms. Fine-grained sediments were accumulated at a low deposition rate, with a low dilution of organic matter. Therefore, high paleoproductivity provided a su cient volume of organisms in the studied area in a quiet deep water body with an anoxic environment and these were the key factors controlling formation of organic-rich rocks.

Acid-base alternation diagenesis and its influence on shale reservoirs in the Permian Lucaogou Formation, Jimusar Sag, Junggar Basin, NW China

The diagenesis and diagenetic facies of shale reservoirs in Lucaogou Formation of Jimusar Sag were studied by means of microscopic observation and identification of ordinary thin sections and cast thin sections,X-ray diffraction,scanning electron microscope and electron probe tests.The results show that alkaline and acidic diagenetic processes occurred alternately during the deposition of Permian Lucaogou Formation in Jimusar Sag.The evolution of porosity in the shale reservoirs was influenced by compaction and alternate alkaline and acidic diagenetic processes jointly,and has gone through three stages,namely,stage of porosity reduction and increase caused by alkaline compaction,stage of porosity increase caused by acid dissolution,and stage of porosity increase and reduction caused by alkaline dissolution.Correspondingly,three secondary pore zones developed in Lucaogou Formation.The shale reservoirs are divided into three diagenetic facies:tuff residual intergranular pore-dissolution pore facies,tuff organic micrite dolomite mixed pore facies,and micrite alga-dolomite intercrystalline pore facies.With wide distribution,good pore structure and high oil content,the first two facies are diagenetic facies of favorable reservoirs in Lucaogou Formation.The research results provide a basis for better understanding and exploration and development of the Lucaogou Formation shale reservoirs.

Classification and control factors of pore-throat systems in hybrid sedimentary rocks of Jimusar Sag, Junggar Basin, NW China

Aiming at the complicated problem of the genesis of high-quality hybrid sedimentary rocks,the pore-throat systems,controlling factors and fluid mobility of hybrid sedimentary rocks in the Permian Lucaogou Formation in Jimusar Sag were examined.The results show that the hybrid sedimentary rocks contain 5 types of pore-throat system,intergranular(Type A),mixed intergranular-dissolved-intercrystalline(Type B),dissolved(Type C),mixed dissolved-intercrystalline(Type D)and intercrystalline(Type E)ones.The pore-throat systems are controlled by 3 major factors,the component content and arrangement(CCA)of hybrid sedimentary rocks,sedimentary environment and diagenesis.CCA controls the matrix support mode of hybrid sedimentary rocks,and therefore controls the types and changes of pore-throat system.The sedimentary environment mainly controls the macroscopic distribution of pore-throat system,i.e.,hybrid sedimentary rocks deposited in the near source and high-energy environment are characterized by high content of coarse-grained component,granular/interbedded-support mode,and development of Type A and Type B pore-throat systems.Hybrid sedimentary rocks deposited in the medium-energy environment far from source are characterized by dolomitic/mud support mode and Type C and Type D pore-throat systems.Hybrid sedimentary rocks deposited in low-energy environment far from source have mainly Type E and Type D pore-throat systems.Diagenetic processes such as compaction and calcite cementation make the proportions of Type A and Type C pore-throat systems decrease further.In the hybrid sedimentary process of sandy-mud,pore-throat system types show a change of"A→B→C→D",in that of dolomite-sand,pore-throat system types show a change of"A→C→D→E"or"B→D→E",and in that of dolomite-mud,pore-throat system types show a change of"D→E",which are affected in details by the contents of coarse-grain component,feldspar and dolomite.The reservoir with Type A pore-throats has the best physical properties and fluid mobility,and the reservoirs with Type D and Type E pore-throats have the poorest.The movable fluid distribution is related to the matrix support mode,and the larger pores in hybrid sedimentary rocks of dolomite/mud support mode have no obvious advantage in fluid mobility.The findings of this study provide a geological basis for evaluating and building reasonable interpretation model of hybrid sedimentary rocks sweet spot.

论清政府对吉木萨尔的经营措施及其意义

清代是吉木萨尔历史上的重要发展时期。这一时期,作为重要的屯垦基地,吉木萨尔发挥着对以乌鲁木齐为中心的东天山军政体系的战略支撑作用,因此,清政府对于吉木萨尔的经营是比较重视的,采取了设官驻兵、屯田移民、开设马厂、建筑城堡、发展文化教育等诸多措施,取得了明显的成效,使得包括吉木萨尔在内的东天山一带成为清朝在新疆统治较为稳固的地区,为同治年间清朝维持对东天山的控制以及将其作为收复新疆的战略基地创造了条件。

陆相混合细粒岩沉积微相及其对甜点的控制作用——以吉木萨尔凹陷芦草沟组为例

【目的】吉木萨尔凹陷二叠系芦草沟组发育了一套陆相混积沉积体系,混积细粒岩沉积微相类型及甜点储层分布规律等研究的不足制约了该区页岩油高效开发。【方法】综合岩心、露头、测井、X射线荧光光谱(X-Ray Fluorescence,XRF)元素录井、分析化验和试油试采等资料,采用岩相构型、沉积微相耦合分析和动静结合等方法,开展了沉积微环境及微相类型划分、沉积模式及其对甜点的控制作用等研究。【结果】(1)研究区主要发育浪成交错层理、水平层理、同生变形构造、黄铁矿、方解石条带、鸟眼构造和结核、缝合线构造、含生物化石和白云岩溶蚀孔8类沉积构造。研究区分为半深湖—深湖、混合浅湖和碎屑浅湖亚相,细分为半深湖泥、云坪、混合滩坝、混合浅湖泥、浅湖砂坝和碎屑浅湖泥等6种微相,不同微相沉积特征及其沉积机制差异明显。(2)建立了咸化湖泊相混积细粒岩沉积微相模式。芦一段自下而上从深湖—半深湖—浅湖演化过程,发育了浅湖砂坝、混合滩坝与云坪微相。其中,云坪呈连片状大范围分布,混合滩坝呈土豆状分布,发育程度较高,不同层规模有差异,浅湖砂坝发育程度一般,呈断续状局限分布,垂向上呈薄储集层与厚层泥岩叠置状。芦二段以浅湖为主,微相类型与芦一段类似,但形态、规模与叠置样式差异较大。云坪和混合滩坝发育数量和规模大大减小,浅湖砂坝则发育程度较高,呈大规模分散土豆状发育,垂向上呈厚层叠置状。不同位置剖面微相的叠置样式不同。(3)甜点段XRF元素分析显示,目的层沉积时为干燥炎热的半咸水环境到咸水过渡环境,古生产力水平较高;下甜点段为富氧环境,上甜点段则为厌氧亚还原到还原环境。(4)沉积微相控制了甜点分布和开发对策。混合滩坝微相Ⅰ类甜点发育程度高,非均质性弱,开发效果最好,采用大规模部署水平井平台化作业进行效益开发。云坪微相Ⅲ类甜点发育,非均质性强,开发效果一般,是后续接替区域。浅湖砂坝Ⅱ类甜点发育,整体分散状,连续性较差,非均质性强,开发效果较好。【结论】后续应在沉积微相空间分布精细研究基础上,参考核磁曲线参数部署水平井开发。

孔喉微观润湿性对页岩油赋存的控制作用——以准噶尔盆地吉木萨尔凹陷二叠系芦草沟组纹层状页岩为例

针对页岩不同类型储集空间中孔喉微观润湿性对其控制作用仍不明确的问题,以准噶尔盆地吉木萨尔凹陷二叠系芦草沟组页岩油储集层为例,综合运用扫描电镜、多阶热解、储集层定量荧光、核磁共振等分析方法,开展纹层状页岩储集空间特征及孔喉微观润湿性对页岩油赋存控制作用的研究。结果表明:芦草沟组主要发育“富火山物质+陆源长英质”纹层状页岩和“富火山物质+碳酸盐”纹层状页岩,其中“富火山物质+陆源长英质”纹层状页岩发育长石溶蚀孔隙和粒间孔隙,孔喉周缘矿物组分主要为长英质矿物组分,呈亲水性特征,主要控制游离态页岩油。“富火山物质+碳酸盐”纹层状页岩发育碳酸盐晶间孔和有机质孔隙,孔喉周缘矿物组分主要呈亲油性特征,控制吸附态页岩油。孔喉周缘主要为油润湿碳酸盐组分时,利于原油的聚集,但使得游离态的油含量比例下降。芦草沟组页岩游离油主要赋存于“富火山物质+陆源长英质”纹层组合的陆源长英质纹层中,成熟度较高、油质较轻。

吉木萨尔芦草沟组页岩油储层润湿性特征与影响因素分析

润湿性是页岩储层的重要物性之一,关系到开发方式的制定和生产制度的优化。借助Amott法与接触角法测定了吉木萨尔芦草沟组储层不同岩性样品的润湿性并对比了两种测试结果的差异;通过RoqSCAN技术测定了岩心表面矿物组分,结合原油组分分析了吉木萨尔芦草沟组储层在不同工作液下的润湿特征并分析了组分对润湿性的影响。此外,通过渗吸驱油实验讨论了润湿性对渗吸驱油效率的影响并筛选了适用于吉木萨尔的表活剂类型。结果表明:岩性与原油物性是影响吉木萨尔芦草沟组储层润湿性的关键因素,其中石英、绿泥石、伊利石含量更高的层段亲水性更强,白云石、黄铁矿、伊蒙混层及高岭石含量更高层段亲油性更强,长石含量对吉木萨尔芦草沟组润湿性的影响不大,原油中胶质沥青质含量更高层段亲油性更强。芦草沟组储层在地层水与瓜胶压裂液环境下普遍偏油湿,非离子类表活剂更加适用于吉木萨尔芦草沟储层,改变润湿性的性能更加稳定,能显著提高亲油岩心的渗吸驱油效率。

吉木萨尔凹陷陆相页岩油储层测井定量解释

以吉木萨尔凹陷二叠系芦草沟组陆相页岩油为研究对象,采用岩芯刻度测井和数据挖掘两种方法,分上、下甜点分别建立物性、含油性、微观孔隙结构及岩石力学等参数的测井定量解释模型,在矿场应用中储层评价精度得到大幅度提高,均达到85%以上。特别是多条曲线反演的渗透率模型,数据挖掘方法优选出3条测井曲线,既反映了绝对孔隙性对渗透率的贡献,又考虑了微观孔隙结构改造对渗透率的制约,用自然伽马和声波时差曲线分别表征泥质含量和压实胶结作用对渗流路径及渗流阻力的影响,相较于单因素模型,其计算精度提高了25.6%。另外,由于井眼环境、孔隙流体的重力分异以及地层在不同方向上的各向异性,水平井与直井测井曲线存在一定的偏差,基于直井测井曲线响应特征与岩芯分析资料建立的解释模型不能直接应用于水平井的储层评价。针对以上难题,建立两种测量方式测井曲线的转换图版和公式,在测井曲线转换的基础上,可以对水平段的储层进行定量解释。

湖相细粒沉积岩中晶粒方解石成因及其对火山-热液活动的指示——以吉木萨尔凹陷二叠系芦草沟组为例

以准噶尔盆地吉木萨尔凹陷二叠系芦草沟组细粒沉积岩中晶粒方解石为研究对象,综合运用岩心观察、薄片观察、阴极发光分析、流体包裹体测试、扫描电镜、同位素组成分析等手段,对湖相细粒沉积岩中自生矿物的成因开展研究。结果表明:晶粒方解石呈层状分布于沉凝灰岩发育层段或沉凝灰岩与泥晶白云岩过渡层段的细粒沉积物中,方解石具有明显的阴极发光环带,可分为3期:Ⅰ期方解石不发光,含有较高的Sr元素,包裹体中包含羰基硫成分,均一温度超过170℃,由火山-热液喷流物质沉积形成;Ⅱ期方解石呈亮黄色光,含有较高的Fe、Mn、Mg元素,轻稀土元素富集,包裹体均一温度高,为热液喷流的钙质环边重结晶形成;Ⅲ期方解石呈暗橙色发光的环带,含有较高的Mg、P、V等元素,稀土元素无明显分异,包裹体均一温度低,为埋藏过程中成岩转化形成。晶粒方解石在垂向上规律性出现,并且其形成温度由颗粒中心向边缘降低,为芦草沟组沉积时期的火山-热液活动提供了直接证据。沉积期火山-热液活动有利于芦草沟组细粒沉积岩中的有机质富集,对优质烃源岩发育有正面效应,并且火山-热液喷流物质在演化过程中易形成晶间孔缝,为页岩油自生自储创造了条件。

新疆吉木萨尔县国家森林公园苔藓植物多样性研究

通过鉴定采集于1993-2019年的951余份标本和文献查询,对吉木萨尔县国家森林公园苔藓植物多样性进行了研究,分析了该区域苔藓植物区系地理成分及特点.结果表明:1)吉木萨尔县国家森林公园共有苔藓植物43科、89属、230种,包括苔类植物门17科、23属、46种和藓类植物门26科、66属、184种,其中重新确定了曾有文献记载但缺少图文描述的宽齿显孔藓(Lewinskya vladikavkana)和摩拉维采木灵藓(Orthotrichum moravicum)两个种.2)优势科有8科,含40属133种,占总科数的18.60%和总种数的57.83%;优势属共5属,包含60种,占该区苔藓植物总种数的26.09%;单种科14个,占总科数的32.56%;单种属46个,占总属的51.69%.3)该地区苔藓植物区系成分主要以北温带分布成分为主,占总种数的64.60%.4)本区苔藓植物植被带可分为山地草原带(1100~1655 m)、山地森林带(1655~2700 m)、亚高山草原带(2700~2900 m)、高山草原带(2900~3200 m)和高山垫状植被带(3200~3900 m)五条带,其中山地森林带苔藓物种数量最多,共207种,占总种数的90.00%.

基于游客体验的乡村旅游发展问题及对策研究——以吉木萨尔县为例

近年来,随着全国休闲农业和乡村旅游呈现“井喷式”的增长态势,我国各地政府都开始围绕农村区域特色旅游产品项目开展深入研究,并获得丰硕成果。吉木萨尔县将发展农村旅游产品视为美好新农村建设的重要支点,但由于资金、人才队伍等缺乏,加之周边乡村旅游产品同质化严重,导致吉木萨尔县乡村旅游发展受限。因此,该文基于游客体验,通过问卷调查收集数据,对吉木萨尔县乡村旅游发展现状、存在问题进行研究,并提出相应的对策建议。

大学生村官职业稳定性影响因素及策略研究——以吉木萨尔县为例

近年来,随着振兴战略的推进和落实,乡村社会、经济、文化等事业发展已经进入一个全新的阶段。农村建设历来是国家重点建设的内容,大学生村官的出现为农村建设带来良好的发展前景。新疆2008年正式启动大学生村官工作,相对于其他实施大学生村官政策较早的省份而言,新疆大学生村官工作启动较晚。相关研究表明,新疆大学生村官对乡村发展产生积极的影响,但是,大学生村官的职业稳定性依然不高。该文通过大量文献阅读、问卷调查和实证分析等方法分析探讨影响大学生村官职业稳定性的因素。调研结果显示,大学生村官职业稳定性不高。究其原因主要包括大学生村官的薪资水平低、工作生活环境较差、自身能力受限、社会认知度低融村难以及政策的不完善。

吉木萨尔县的历史沿革与区域发展规划

新疆吉木萨尔县在汉代是西域都护府管辖的戊己校尉屯田地,在魏晋北朝时期属于西域高昌郡,唐代在此地设立北庭都护府。五代宋辽时期,这里先后被高昌回鹘、西辽统治,蒙元在此设立别失八里等处行尚书省。清统一新疆后,在这里设置济木萨尔巡检,后更名孚远县。新中国建立后,孚远县改名为吉木萨尔县,隶属昌吉州至今。作为乌鲁木齐东北部的重要卫星城,吉木萨尔县与阜康、奇台、巴里坤、富蕴、青河等地,共同拱卫着首府城市和新疆的安全。东天山北麓地区的各个城镇,通过公路铁路相互连接,组成了新疆地区通往中原内陆的重要通道。吉木萨尔县有着丰富的矿产资源和良好的自然环境,有利于各产业的均衡发展。以东天山北麓城镇群构建辐射带,不仅能促进该地区新时代中国特色社会主义政治、经济、文化事业的繁荣发展,同时也能为维护祖国统一与领土完整作出贡献。

准噶尔盆地吉木萨尔凹陷凝灰岩型致密油特征与成因

通过岩心和薄片观察,结合X光衍射、电子探针和地球化学分析,对准噶尔盆地吉木萨尔凹陷二叠系芦草沟组凝灰岩型致密油特征与成因进行综合研究。芦草沟组沉积岩中发育凝灰岩、沉凝灰岩和凝灰质白云岩夹层。凝灰岩类中碱性长石、石英均表现出富Sr特征,矿物地球化学分析显示其来自碱性—过碱性岩浆岩。白云石87Sr/86Sr值与地幔值非常接近,表明凝灰岩类组成矿物形成于与岩浆作用相关的热液环境。白云石Sr/Ba值较高,δ13C较重,扫描电镜下发现石盐晶体,表明芦草沟组沉积于较高盐度的环境。与火山作用、地幔热液有关的富Mg2+、Fe2+和高盐度湖泊环境促进了白云石的沉淀。致密油分布、烃源岩有机质丰度和储集层物性表明,火山活动提供的丰富营养物质控制了高丰度烃源岩形成。剩余粒间孔和溶蚀孔发育的凝灰岩、凝灰质白云岩为有利储集层发育层段。凝灰岩类控制了致密油的形成与分布。

致密油源储特征与聚集机理——以准噶尔盆地吉木萨尔凹陷二叠系芦草沟组为例

基于岩心观察、岩石样品薄片鉴定和X射线衍射矿物分析、烃源岩样品有机碳含量测定、岩石热解等方面的研究及储集岩高压压汞和核磁共振等分析,结合其埋藏及生烃史,分析准噶尔盆地吉木萨尔凹陷中二叠统芦草沟组烃源岩特征及储集岩特征,探究其源储组合及致密油聚集机理。芦草沟组烃源岩有机质类型总体上为Ⅰ型和Ⅱ型,TOC值平均为4.6%,整体上为优质烃源岩,处于低成熟—成熟阶段。烃源岩可划分为页岩、泥岩和粉砂质泥岩3类。芦草沟组储集岩整体上具有低孔低渗特征,高压压汞与核磁共振实验表明：纳米级孔喉（孔喉半径主体为50-500 nm）是储集空间的主体。储集岩可划分为泥质粉（细）砂岩、白云质粉（细）砂岩和砂屑白云岩3类。芦草沟组具有纵向上＂源储共生＂、横向上连续分布的源储组合关系,且烃源岩持续生烃。综合分析认为：自晚侏罗世至今,芦草沟组烃源岩大规模持续生烃增压为致密油聚集提供持续动力和物质供应,保障了石油在致密储集层中持续有效地充注聚集,形成大规模致密油资源。

吉木萨尔凹陷芦草沟组泥质岩类生烃潜力差异性分析

吉木萨尔凹陷芦草沟组为吉木萨尔凹陷最主要的烃源岩,该套烃源岩岩性多样,多为过渡性岩类,为了研究不同泥质岩类生烃潜力特征的差异性,以录井岩芯为基础,将泥质岩类划分为纯泥岩、砂质泥岩、灰质泥岩和云质泥岩四类,并主要从有机地球化学的角度对四类岩性泥岩的生烃潜力特征做出评价。结果表明,纯泥岩有机质丰度较云质泥岩、灰质泥岩、砂质泥岩略高;纯泥岩有机质类型最好,其次是灰质泥岩和云质泥岩,砂质泥岩干酪根类型最差。在此基础上,结合HI分析,认为纯泥岩生烃潜力最高,其次是云质泥岩、砂质泥岩,灰质泥岩生烃潜力最差。

烃源岩特征与生烃动力学研究——以准噶尔盆地吉木萨尔凹陷芦草沟组为例

准噶尔盆地吉木萨尔凹陷二叠系芦草沟组含有丰富的油气资源,其烃源岩主要有页岩、碳酸盐质页岩和粉砂质泥岩,它们均具有有机质丰度高、生烃潜力大、当前处于低成熟至成熟阶段、有机质类型以Ⅰ型和Ⅱ型为主的特征,在对其特征进行评价的基础上,选取中—低成熟度、有机质丰度较高的烃源岩进行开放体系条件下的热解实验和动力学模拟实验,进而研究烃源岩样品的生排烃特征。结果表明,芦草沟组烃源岩活化能主要为210 k J/mol;上述3种烃源岩中,页岩具有最高的生烃量和排烃效率,碳酸盐质页岩次之,而粉砂质泥岩的生烃量和排烃率均最低,但前两者却具有较高的滞留烃含量。综合前人的研究成果,最终认为芦草沟组烃源岩生烃增压作用是烃源岩排烃和致密油气聚集的主要动力,页岩和碳酸盐质页岩段是致密油勘探的目标层段。

吉木萨尔凹陷致密油储层物性定量预测

准噶尔盆地吉木萨尔凹陷致密油已成为近年中国非常规油气研究的热点,但储层预测多采用常规方法,难以应对致密油深入研究遇到的复杂问题。为进一步探索致密油储层预测的有效方法,解决致密油目前存在的储层预测难题,综合录井、测井和化验分析结果,将吉木萨尔凹陷芦草沟组致密油储层划分为上、下2套"甜点体",将孔隙度作为致密油"甜点"储层分类的单一敏感参数,并利用多属性综合分析方法确定上、下"甜点体"对孔隙度敏感的地震属性,再采用非线性回归算法,定量预测累计厚度大于4m的"甜点体"储层最大孔隙度。最终明确了吉木萨尔凹陷芦草沟组致密油优势储层发育在凹陷的南部,指明了吉木萨尔凹陷致密油下一步勘探方向。