Reservoir space of the Es_3~3–Es_4~1shale in Dongying sag

The Es3/3-Es1/4 shales in Dongying sag are source rocks with large reserves of shale oil and gas. For the iden- tification of development characteristics and geological significance of the reservoir space, FM1 logging, core observation, thin section analysis, X-ray diffraction, fluorescence microscopy, scanning electron microscopy, mercury porosimetry, low-temperature nitrogen adsorption, atomic force microscopy, and conventional physical property testing were used to study the petrology and reservoir space of the Es3/3-Es1/4 shale in Dongying sag. The results suggest that the shale is rich in carbonate minerals. Phanero- crystalline stratiform and lamellar argillaceous limestone and calcareous claystone are the oil- and gas-bearing lithofacies. The oil in the micropores is mainly present as membranes and clots. The shale reservoir space has a network structure with veins, carbonate and clay minerals, and micropores among pyrite and the matrix. The results provide the geological framework for future shale oil and gas explora- tion in Dongying sag.

Combination and distribution of reservoir space in complex carbonate rocks

This paper discusses the reservoir space in carbonate rocks in terms of types,combination features,distribution regularity,and controlling factors,based on core observations and tests of the North Truva Oilfield,Caspian Basin.According to the reservoir space combinations,carbonate reservoirs can be divided into four types,i.e.,pore,fracture-pore,pore-cavity-fracture,and pore-cavity.Formation and distribution of these reservoirs is strongly controlled by deposition,diagenesis,and tectonism.In evaporated platform and restricted platform facies,the reservoirs are predominately affected by meteoric fresh water leaching in the supergene-para-syngenetic period and by uplifting and erosion in the late stage,making both platform facies contain all the above-mentioned four types of reservoirs,with various pores,such as dissolved cavities and dissolved fractures,or structural fractures occasionally in favorable structural locations.In open platform facies,the reservoirs deposited continuously in deeper water,in an environment of alternative high-energy shoals（where pore-fracture-type reservoirs are dominant） and low-energy shoals（where pore reservoirs are dominant）.

Reservoir space types and the factors influencing the characteristics of spherulite in rhyolite

Oil-gas reservoir space types involving spherulite in pyromeride rocks are common in the Lower Cretaceous Shangkuli Formation, the Hailar Basin, China. The main types include interspherulite fissures, interlayer fissures, intraspherulite concentric rings and net microcracks, cavity pores, dissolution pores, and devitrification pores. The first two were found to restrict the effective plane porosity of interspherulite. Devitrification microporosities, microcracks, cavity pores, and spherulite diameter influence the effective plane porosity of intraspherulite. The degree of dissolution is determined by the degree of development and the type of intraspherulite microcracks. Another important role of ring and net microcracks is to connect devitrification pores to form a pore and fissure network. Finally, chilling contraction plays an important role in the form and development of interspherulite fissures, microcracks, and cavity pores. The diameter of spherulite restricts chilling contraction, especially when the diameter is between the common spherulites and lithophysae, thus benefiting microcrack and cavity pore formation. To summarize, devitrification microporosities represent excellent oil reservoir space, while offering micro-channels for the movement of formation water and organic fluids. However, the inclusion of microcracks improves this capacity.

The influence of pore structure on P-& S-wave velocities in complex carbonate reservoirs with secondary storage space

Secondary storage spaces with very complex geometries are well developed in Ordovician carbonate reservoirs in the Tarim Basin,which is taken as a study case in this paper.It is still not clear how the secondary storage space shape influences the P-＆ S-wave velocities （or elastic properties） in complex carbonate reservoirs.In this paper,three classical rock physics models （Wyllie timeaverage equation,Gassmann equation and the Kuster-Toks z model） are comparably analyzed for their construction principles and actual velocity prediction results,aiming at determining the most favourable rock physics model to consider the influence of secondary storage space shape.Then relationships between the P-＆ S-wave velocities in carbonate reservoirs and geometric shapes of secondary storage spaces are discussed from different aspects based on actual well data by employing the favourable rock physics model.To explain the influence of secondary storage space shape on V P-V S relationship,it is analyzed for the differences of S-wave velocities between derived from common empirical relationships （including Castagna＇s mud rock line and Greenberg-Castagna V P-V S relationship） and predicted by the rock physics model.We advocate that V P-V S relationship for complex carbonate reservoirs should be built for different storage space types.For the carbonate reservoirs in the Tarim Basin,the V P-V S relationships for fractured,fractured-cavernous,and fractured-hole-vuggy reservoirs are respectively built on the basis of velocity prediction and secondary storage space type determination.Through the discussion above,it is expected that the velocity prediction and the V P-V S relationships for complex carbonate reservoirs should fully consider the influence of secondary storage space shape,thus providing more reasonable constraints for prestack inversion,further building a foundation for realizing carbonate reservoir prediction and fluid prediction.

川中侏罗系自流井组大安寨段页岩油储层特征及其勘探启示

为进一步指导四川盆地侏罗系自流井组大安寨段页岩油的勘探与开发,亟需理清页岩油的有利赋存岩相。通过岩心观察、薄片鉴定、高压压汞、核磁共振、岩石热解等实验,分析大安寨段页岩层系不同岩相的储集空间类型、孔隙结构特征及含油性。结果表明,大安寨段主要发育块状(泥质)介壳灰岩、层状泥质介壳灰岩、层状介壳页岩、纹层状含介壳页岩、块状含介壳黏土质页岩和页理状含粉砂黏土质页岩6类岩相;页岩物性远优于介壳灰岩,且随着灰质含量的增加孔径逐渐增大,但总孔体积和总连通体积逐渐减小;大安寨段页岩层系平均游离油(S1)值为1.31 mg/g,含油性中等,页理状含粉砂黏土质页岩与纹层状含介壳页岩S1值较高,分别为2.37 mg/g与1.82 mg/g。页理状含粉砂黏土质页岩和纹层状含介壳页岩的储集性较好、含油性较高,两者构成的岩相组合可作为大安寨段页岩油的重点勘探对象。

四川盆地元坝地区千佛崖组二段细粒沉积岩岩相特征及储集性分析

四川盆地侏罗系千佛崖组页岩油气勘探前景良好,但目前对其细粒沉积岩基本沉积特征及发育规律的认识还不足。为此,利用细粒沉积学原理,依据岩心和测井资料,通过岩心精细描述、薄片鉴定、X衍射全岩分析及扫描电子显微镜观察等技术手段,精细描述了元坝地区千佛崖组二段(简称千二段)细粒沉积岩储层的物质组成、沉积构造、储集空间类型等地质特征,划分了岩相类型,并对主要岩相储层的物性特征和储集空间类型进行分析与比较,明确了有利层段发育位置。研究结果显示:(1)千二段陆相细粒沉积岩可划分成“黏土岩”和“粉砂岩”2种岩石类型,15种岩相类型。其中,富有机质块状黏土岩、富有机质块状含粉砂黏土岩、富有机质纹层状含粉砂黏土岩、富有机质条带状含粉砂黏土岩、富有机质块状粉砂质黏土岩和富有机质纹层状粉砂质黏土岩为6种主要岩相类型。(2)储层储集空间类型多样,包括黏土矿物层间缝、层理缝、黏土矿物晶间孔、黄铁矿晶间孔、溶蚀孔及有机孔等,其中黏土矿物晶间孔分布最为广泛。(3)6种主要岩相的平均孔隙度和渗透率分别为2%和0.023×10^(-3)μm^(2),富有机质纹层状含粉砂黏土岩、富有机质纹层状粉砂质黏土岩和富有机质块状粉砂质黏土岩的储集空间类型丰富,分布广、数量多,孔隙度与渗透率均高于其他岩相且TOC值较高,是最有利的储集岩相类型。(4)千二段有利层段位于其(1)小层全段、(2)小层的底部和(3)小层的中下部。

济阳页岩油开发“三元”储渗理论技术与实践

基于济阳坳陷页岩油储层上万米岩心资料与60余口水平井的开发实践,提出济阳页岩油“储元”、“缝元”、“压元”的“三元”储渗理论。“三元”协同支撑济阳页岩油的富集高产:“储元”控制页岩油的富集,咸化湖盆无机孔-缝及灰-泥优质纹层组构发育利于页岩油储集,高生烃能力、高游离烃含量为高产提供物质基础;“缝元”控制页岩油的渗流,天然裂缝为页岩油的运移和聚集提供渗流通道,压裂改造缝沟通天然裂缝形成复杂缝网,为高产提供渗流基础;“压元”控制页岩油的高产稳产,高地层压力为油气运聚提供原始动力,压裂增能可进一步提高岩石及流体弹性能,强化孔缝原油渗吸置换,减缓应力敏感性,为长期稳产提供能量基础。基于“三元”储渗理论,形成了以立体井网优化、立体均衡压裂、全周期优化调控为核心的立体开发技术,有效指导了现场生产实施,为济阳页岩油规模化效益开发提供技术支撑。

东营凹陷沙河街组页岩中纹层状亮晶方解石成因与储集意义

济阳坳陷东营凹陷古近系沙四段上亚段、沙三段下亚段是胜利油田页岩油的主要分布层位,发育富灰型、混积型、富长英质型3种页岩储层类型,其中富灰型页岩最为发育。富灰型页岩中亮晶方解石纹层发育段具有良好的储集性、含油性、渗透性、可压性特征,在牛庄、民丰、利津等洼陷多口水平井获得峰值日产油超百吨的良好效果。利用普通薄片、阴极发光、包裹体分析、同位素地球化学分析以及氩离子抛光扫描电镜等测试手段,分析了纹层状亮晶方解石的成因机制及其储集意义。结果表明,纹层状亮晶方解石分为重结晶的晶粒方解石纹层和生排烃形成的纹层状亮晶方解石脉。重结晶的晶粒方解石纹层是湖泊自生沉淀的泥晶方解石纹层在早成岩阶段原地重结晶形成的,其形成过程与浅埋藏期硫酸盐细菌还原作用密切相关,方解石晶体呈粒状,形态不规则,纹层厚度稳定,分布连续;纹层状亮晶方解石脉的形成则与有机质热演化成熟时期的生排烃密切相关,有机酸溶解了页岩中的泥晶方解石形成富碳酸盐流体,这些流体在生烃压力的作用下顺纹层间裂缝运移后再次结晶沉淀形成方解石脉体,纹层相对较厚,呈透镜状,平面上断续分布。2种亮晶方解石纹层中广泛发育层间缝(层理缝)、晶间缝和晶间孔、溶蚀孔,宏孔占比高,连通性好。亮晶方解石纹层与富有机质泥质纹层呈“层偶状”频互层,构成富有机质纹层状亮晶泥质灰页岩、富有机质纹层状亮晶灰质泥页岩2种岩相类型,“源储”一体,页岩品质好,是济阳页岩油富灰型页岩中最为有利的岩相类型。

塔里木盆地富满断控破碎体油藏储集类型特征与注水替油效果

塔里木盆地走滑断裂控制的超深油气藏是近年来中国油气勘探开发最重要领域之一,但目前该类型油藏的储集空间类型并不清楚,不同储集空间类型与注水效果关系不明确,严重制约了富满油田的高效开发。在充分分析野外露头、岩心、成像测井以及动态监测资料的基础上,系统剖析了断控破碎体的3种主要储集空间类型及其与注水效果的关系。提出了断控破碎体的概念,指出富满油田主要为断控破碎体油藏,研究结果表明:①断裂空腔型储集体主要分布在断裂带的核部,由断层滑动面产状变化引发内部体积调整形成了“空腔”型洞穴。埋藏条件下的储集空间相对较为封闭,内部孔隙空间较大,注水后原油置换率较高,部分油井动用储量的注水采收率可高达93%。②角砾间孔隙型储集体主要分布在断裂带的核部,由相邻的角砾相互支撑而形成角砾间不规则储集空间类型。该类储集体分布较为均匀,孔隙度中等,单位压降下的产液量较高,但是由于储集空间内部连接并不通畅,注水后置换率较低,需要研究探索构建立体结构井网来提高开发效果。③构造裂缝型储集体主要分布在断裂带的损伤带和过程带,在断层带的两侧和端部发育形成一定宽度的裂缝带。裂缝带周边也会发育少量孔隙,部分区域会形成一定的渗流优势通道,因此注入水的流失量较大,注水效果相对于断裂空腔型储集体较差。研究成果支撑了富满油田上产原油350×10^(4) t,可助推注水开发方案和提高采收率方案的优化,对同类型油藏高效开发具有重要的借鉴意义。

苏北盆地古近系阜宁组二段页岩油储集空间特征及甜点段评价——以溱潼凹陷QY1井为例

苏北盆地古近系阜宁组二段是常规油重点产层,同时也是中国东部陆相页岩油勘探开发的优选层位。对溱潼凹陷QY1井岩心样品进行分析测试表明,该套页岩具有低有机质丰度、较低镜质体反射率(R_(o))、矿物组分均衡及孔隙网络复杂的特点;运用岩石学及地球化学方法等对该页岩油储层的岩相特征、储集空间特征、含油性与可动性、脆性指数与可压性特征等进行研究,指明了生产甜点段。阜二段是一套混积页岩纹层型储层,矿物组成以黏土、长英质和碳酸盐矿物为主,有机碳含量平均值为1.32%,R_(o)为0.9%~1.1%;平均孔隙度中下部为4%,上部为2.2%。根据“有机质丰度+构造特征+岩性”将阜二段页岩划分为6种岩相,其储集性具有明显差异,纹层发育特征的差异是导致不同岩相具有不同储集空间特征的重要原因。除低有机质纹层/层状灰云质页岩外,其他岩相都具有较好的含油性;高有机质层状灰质页岩的有机碳含量最高。纹层数量与油气可动性具有较好的对应性,从中有机质纹层状含灰云页岩到高有机质块状泥岩,平均含油饱和度指数从202.62 mg/g降至77.83 mg/g。高有机质块状泥岩由于存在大量塑性矿物,造缝效果是6种岩相中最差的。中有机质纹层状含灰云页岩是最优岩相,中有机质层状含灰云页岩和中有机质纹层/层状灰云质页岩略差,但也可以作为优势岩相成为勘探开发的重点。根据优势岩相在纵向上的分布,优选阜二段Ⅰ亚段③—⑤小层和Ⅱ亚段②—④小层为该区地质甜点段。

郁江走滑断裂带北部储集空间发育特征及主控因素

为探索走滑断裂破碎带储集空间发育特征和形成机理,综合应用野外露头、遥感影像和岩心测试资料,对郁江走滑断裂带北部储集空间进行识别刻画和量化分析,并探讨其发育主控因素。结果表明:郁江走滑断裂带北部破碎带在平面上可分为北部张扭段和南部压扭段,不同段储集空间发育特征存在差异,张扭段裂缝开度更大,压扭段裂缝长度、裂缝线密度、破碎区面积和洞穴面积更大,总体上,压扭段储集空间发育规模相对较大;走滑断裂带构造应力是决定优势储集空间发育的外部因素,岩层厚度和岩石矿物组成是控制储集空间发育的内部因素,岩层厚度大于1 m且碳酸钙含量低于70%的碳酸盐岩经压扭作用改造后,可形成缝洞型储集体有利发育区。

Shale oil development techniques and application based on ternary-element storage and flow concept in Jiyang Depression,Bohai Bay Basin,East China

The ternary-element storage and flow concept for shale oil reservoirs in Jiyang Depression of Bohai Bay Basin,East China,was proposed based on the data of more than 10000 m cores and the production of more than 60 horizontal wells.The synergy of three elements(storage,fracture and pressure)contributes to the enrichment and high production of shale oil in Jiyang Depression.The storage element controls the enrichment of shale oil;specifically,the presence of inorganic pores and fractures,as well as laminae of lime-mud rocks,in the saline lake basin,is conducive to the storage of shale oil,and the high hydrocarbon generating capacity and free hydrocarbon content are the material basis for high production.The fracture element controls the shale oil flow;specifically,natural fractures act as flow channels for shale oil to migrate and accumulate,and induced fractures communicate natural fractures to form complex fracture network,which is fundamental to high production.The pressure element controls the high and stable production of shale oil;specifically,the high formation pressure provides the drive force for the migration and accumulation of hydrocarbons,and fracturing stimulation significantly increases the elastic energy of rock and fluid,improves the imbibition replacement of oil in the pores/fractures,and reduces the stress sensitivity,guaranteeing the stable production of shale oil for a long time.Based on the ternary-element storage and flow concept,a 3D development technology was formed,with the core techniques of 3D well pattern optimization,3D balanced fracturing,and full-cycle optimization of adjustment and control.This technology effectively guides the production and provides a support to the large-scale beneficial development of shale oil in Jiyang Depression.

Interaction Mechanism between Formation Process of Bank Collapse Disaster Chain and Territorial Space Utilization of Large Reservoirs

Number of reservoirs in China ranks the first in the world. Due to the complex geology, and superimposing rainfall and reservoir water fluctuation, the bank collapse chain is prone to disasters. The Yangtze River Reservoir is key geological disaster prevention area. Studying the process of reservoir disaster is significant because of the limited territorial space utilization. Scientific and technological issues, i.e., the mechanism of bank collapse disaster chain of large reservoirs, the interaction mechanism of bank collapse disaster chain and territorial space utilization, the early identification, monitoring technology and ecological prevention and control technology system of disaster chain, and the territorial space geological safety and control technology system are focused. We consider the material transformation, energy transfer and information transmission in disaster chain;adopt the survey, Space-Air-Ground integrated monitoring, theoretical analysis, numerical simulation and the multidisciplinary research methods;reveal the chain source development, evolution process of secondary and derivative disasters;explore the interaction mechanism of disaster chain and territorial space utilization;construct the system of early identification, monitoring, early warning, control and ecological preven-tion to achieve Emission Peak and Carbon Neutrality;provide theoretical and technical support for the territorial space geological safety, regulation and utilization of large reservoirs.

松辽盆地古龙凹陷白垩系青山口组页岩油储层中微米孔缝特征及油气意义

通过岩心观察、薄片鉴定、电子背散射、二次成像及能谱分析等多种实验手段,对松辽盆地古龙凹陷白垩系青山口组页岩油储层中的微米孔和微米缝进行了研究。研究结果表明:(1)古龙凹陷页岩油储层岩性为以页岩为主的细粒碎屑岩,矿物成分以黏土和长英质为主,在结构上显示出泥岩或页岩的特点,整体为长英质页岩;储层中微米孔、缝发育,类型多样。(2)研究区微米孔直径一般为1~2μm,最大可达70μm,多呈近圆形、扁圆形、多角形和不规则形,按成因可分为压实应力屏蔽孔、成岩自生孔、溶蚀孔、生排烃扩张孔、有机质孔和硅藻残留孔6类;压实应力屏蔽孔多发育在刚性矿物的两侧;成岩自生孔常发育在白云石、绿泥石、伊利石等成岩自生矿物中,以晶间孔为主;溶蚀孔多发育在碳酸盐矿物中,内部可见次生菌丝状絮凝体;生排烃扩张孔多呈垂直或近垂直成列产出,与轻质油形成的二次生烃和排烃有关;有机质孔发育在有机质内部,与植物的残留细胞及轻质油和天然气的充填有关;硅藻残留孔主要发育在硅藻内部和边缘,孔径较大,一般为数微米至数十微米。(3)研究区微米缝以顺层为主,宽一般为1~10μm,最大可达100μm,长主要为数微米至数十微米,可见毫米级;可分为成岩收缩缝、溶蚀缝、生排烃扩张缝和构造/剪切缝4类,成岩收缩缝以张性缝为主,缝弯曲,缝壁参差不齐;溶蚀缝宽度可达60~70μm,裂缝内可见自生黏土,缝两侧有黄铁矿、磷灰石和白云石等自生矿物;生排烃扩张缝两侧多锯齿状参差不齐,绕过刚性矿物;构造/剪切微米缝一般平直,有与剪切相关的其他裂缝伴生。(4)研究区不同尺度的孔、缝之间连通性较好,形成了“纳米孔+纳米缝、微米孔+微米缝、毫米孔+毫米缝”三级储集和输导体系。

塔北地区鹰山组下段—蓬莱坝组白云岩成因及控储意义

为确定塔北地区中—下奥陶统鹰山组下段—蓬莱坝组白云岩成因,通过岩心及岩石薄片观察,利用阴极发光、X射线衍射有序度、碳氧稳定同位素、锶同位素和稀土元素组成及配分模式分析,并将岩石学与地球化学特征结合,开展了塔北地区鹰山组下段—蓬莱坝组白云石化作用研究。粉—微晶白云石和粉—细晶他形脏白云石由同生期高盐度海水白云石化作用形成,流体主要源自地表低温蒸发条件下的高盐度海水;粉—细晶自形白云石由早成岩期浅埋藏白云石化作用形成,流体主要源自奥陶纪海水,流体温度因埋藏加深而升高;鞍形白云石由早成岩期热液白云石化作用形成,流体主要源自奥陶纪海水,且有后期深部岩浆热液加入。同生期高盐度海水白云石化作用不产生储集空间,但由于区域局限,蒸发强烈,可伴随石膏沉淀,石膏溶蚀后形成储集空间;早成岩期浅埋藏白云石化作用可形成自形白云石,促进晶间孔的发育,成岩后期溶蚀流体易进入,溶蚀形成晶间溶孔和溶蚀孔隙;早成岩期热液白云石化作用不利于储集空间的形成。

长岭断陷查干花次凹火石岭组火山岩喷发模式新认识

长岭断陷查干花次凹火石岭组火山岩岩石类型及岩性组合与典型火山碎屑岩存在差异,其岩心、薄片见火山灰球、淬碎角砾等特殊构造,储集层物性较差,无典型的火山岩丘状包络机构,火山岩可能形成于特殊的喷发环境。根据地震波反射特征、岩心描述、薄片特征及分析化验资料,识别不同喷发环境的典型标志,结合已钻井岩性组合、区域构造背景等,建立该区的火山喷发堆积模式。研究表明:该区火山岩经历了3个喷发期次,分别处于陆上、水陆交替和水下喷发环境。水下喷发火山岩纵横比小,常呈宽缓盾状,原生孔隙不发育,溶蚀孔、脱玻化孔等发育,储集空间整体以中—小孔隙为主。陆上喷发火山岩孔隙较发育,物性较好,为油气勘探开发的主要目标。

延安气田致密砂岩气藏开发井距优化研究

鄂尔多斯盆地延安气田上古气藏是典型的强非均质多层复杂叠置致密砂岩气藏,单井控制规模小、开发及动用难度大,为提高区块开发效果,在地质及气藏动态研究基础上,优选泄气半径法、干扰试井法、经济评价法对延安气田Y145井区开发井距进行优化调整。泄气半径法结果表明,井距在580~736 m较为合适;干扰试井法结果表明,山2层>500 m较为适宜,山1及盒8层控制规模相对山2较为有限;经济评价法结果表明,Ⅰ+Ⅱ类储量区整体经济极限井距为617 m,合理井距为702 m。综合3种方法的研究结果,得出在目前经济技术条件下,采用600~700 m井距逐步完成加密调整可进一步提高区块储量动用程度和整体采收率。该研究可为同类气田井网加密调整提供一定的理论依据。

不同序级走滑断裂对碳酸盐岩储集层发育的控制差异

断控岩溶体系储集空间结构差异制约该类油藏高效开发。目前,对高序级走滑断裂储集层储集空间结构研究较深入,但对低序级走滑断裂储集层储集空间结构研究较少。以塔里木盆地北部坳陷富满油田为例,从断裂活动强度、沉积环境、岩性等方面展开分析,对比不同序级走滑断裂储集层储集空间结构成因及差异,并分析了低序级走滑断裂的成因及勘探潜力。高序级走滑断裂活动强烈,储集层在剖面上呈倒三角式破碎,储集层规模由上至下逐渐减小;低序级走滑断裂活动强度相对较弱,储集层在剖面上呈正三角式破碎,储集层规模由上至下逐渐增大。低序级走滑断裂对地层的破碎规模影响有限,密集发育的裂缝网络可以导致储集层大规模破碎,影响储集层发育的主要因素是沉积环境和岩性。富满油田深层低序级走滑断裂由西向东可分为3个区域,勘探潜力大。

松辽盆地XS气田营城组火山岩储层储集空间类型及形成演化

为研究确定松辽盆地XS气田营城组致密火山岩储层储集空间类型及优质储层成因,综合岩石薄片、扫描电镜等多种技术资料,在XS气田营城组火山岩储层特征、储集空间研究基础上,恢复致密火山岩孔隙的形成演化。结果表明:(1)XS气田营城组火山岩储集空间包括原生孔、次生孔和裂缝3大类16种类型;(2)火山岩储集空间的形成经历了初始成岩、表生淋滤和埋藏成岩3个阶段,初始成岩期的冷凝成岩和气体逸出形成各类原生孔隙,虽然表生淋滤期热液蚀变和深埋成岩期碳酸盐胶结造成储层物性大量损失,但大气淡水和有机酸溶蚀形成的次生孔隙有利于物性改善,构造破裂形成的裂缝作为流体运移通道促进了次生溶蚀作用的进行;(3)岩性、岩相、构造和成岩作用共同控制了火山岩储集空间和物性的演化,其中岩性为次生改造提供了物质基础,岩相控制了原生孔隙的形成与分布,构造作用形成不同规模的裂缝,增加储集空间、沟通不同类型孔隙提高渗透性,不同类型胶结物的沉淀等成岩作用,造成原生孔隙丧失和次生孔隙破坏。该研究为XS气田优质储层预测和高效开发提供了依据。

超低渗油藏水平井井间干扰影响因素分析及井距优化

鄂尔多斯盆地超低渗油藏开发已进入中期,新井加密和老井重复压裂已成为区域采收率提高的重要手段,体现出井间距持续变小,压裂规模持续增长的趋势,导致出现井间干扰程度高以及单井产量快速递减等问题。为解决井间干扰程度评价及预防控制等问题,利用油藏数值模拟方法,建立了水平井组数值模拟模型,评价单井及井组压裂改造后动用范围,开展井间干扰程度影响因素分析。结果表明:基质渗透率及天然裂缝渗透率越高,单井压裂规模越大,井间距越小,井间干扰程度越明显。单井EUR和区块整体采收率存在最佳匹配关系,需要优化合理井距来平衡区块采收率和单井累积产量的关系。以上研究结果可为井距优化及重复压裂技术应用提供有效指导。