Based on image analysis methods such as rock thin sections,scanning electron microscopy,micro fluorescence,and cathodoluminescence,combined with testing techniques such as nuclear magnetic resonance and nitrogen adsorption,two typical lithofacies of the Paleogene carbonate mineral shale and mixed shale in Dongying Sag were studied.According to the mineral composition and occurrence,shale was divided into two types of structural units:carbonate laminas and mudstone laminas.By analyzing the mineral types and related pore development characteristics of them,two typical lithofacies reservoir characteristics were revealed.In view of the relative changes in geological elements during burial,the development conditions of shale reservoir space were discussed.The research results indicate that the Paleogene shale in Dongying Sag has diverse mineral components,characterized by the widespread development of multi-component carbonate minerals,local concentration of multiple sources of felsic detrital particle,and plastic filling of rheological components such as clay minerals and organic matter.The skeletal par-ticles limit the distribution boundaries of organic components,and the organic components contain some autogenous minerals.The pore filling materials are influenced by factors such as the high content of crude oil asphaltene and wax,as well as high sur-face solidification points.The organic components and inorganic minerals exhibit multiple chimeric characteristics.The shale fab-ric and complex evolution process jointly determine the diversity of pore types and development mechanisms.The carbonate min-eral shale develops nanoscale intracrystalline pores and micrometer-scale intergranular(solution)pores,characterized by large and well-connected pores,with relatively low porosity.Mixed shale develops nano-sub micron-sized interlamellar pores of clay minerals,which are small and poorly connected,with relatively high porosity.The interlayer fracture development zone has good reservoir properties,and the reservoir space is composed of multi-scale networks rich in matrix pores.In the overall background of rich organic matter,the Paleogene rich carbonate shale has the characteristics of the oil enrichment in matrix pores and at the laminae planes.

Shale oil in Jiyang continental faulted basin is a realistic new field for subsequent resource,with enormous exploration potential.It is an important resource base for the sustainable development of Shengli Oilfield.The results of geological research and exploration of shale oil were analyzed in Jiyang continental faulted basin in recent years,and the new progress was systematically reviewed in shale sedimentation,reservoir formation,hydrocarbon generation,shale oil enrichment theory,and supporting fractur-ing stimulation technologies for Jiyang continental faulted basin.The results show that ① A shale lithofacies classification scheme is proposed based on mineral composition,sedimentary structure,crystallization,and abundance of organic matter,which can be summarized as"four elements and three ends."The mechanism of"four paleo-environment factors control shale lithofacies"is re-vealed,and the orderly"ring-shaped"distribution of shale lithofacies is confirmed.② The core micro/nano CT scanning,argon ion polishing scanning electron microscopy,FIB-FESEM,nuclear magnetic resonance freeze-thaw,and small-angle X-ray scattering are integrated to form the quantitative characterization technologies of multi-scale shale pore and fracture systems.It is clear that the spaces of the shale reservoir in Jiyang continental faulted basin are divided into both pores and fractures,mainly inorganic pores and fractures.It is revealed that calcite recrystallization,dissolution,and conversion from illite/smectite to illite are the most critical res-ervoir formation mechanisms,and a reservoir model of shale pore and fracture network is established.③ The oil content evaluation method of organic-rich shale is developed,which reveals the characteristics of high paleo-productivity,early generation,and early enrichment of organic-rich shale in the saline lake basin.The shale oil resources in Jiyang continental faulted basin are estimated to be more than 1010 t.④ The shale oil enrichment is controlled by the spatiotemporal coupling of hydrocarbon generation and reser-voir formation of bedded/laminated shale,which is characterized by"early formation of saline source rock,inorganic pore,and fracture reservoirs,microscopic source-reservoir integration,and dual coupling enrichment."⑤ The comprehensive evaluation sys-tem and target selection process for shale oil exploration in continental faulted basins are established,which involves four character-istics and four determinations.⑥ The fracturing stimulation technologies are developed of"combined fracture network fracturing"and"horizontal well multistage fracturing"suitable for Jiyang continental faulted basin.According to the actual situation of Shengli Oilfield,the exploration idea is proposed of"increasing storage and production in main subsags,exploring new positions in small oil-rich subsags,implementing resources in peripheral small subsags,and taking into account the optimization of mineral rights,"to orderly promote the large-scale increase in storage and production of shale oil in Jiyang continental faulted basin.The relevant achievements and supporting technologies are significant for shale oil exploration and development in similar oilfields.

元古界基岩潜山油气藏是柴达木盆地北缘马海东地区油气勘探的重要领域之一,储层是影响基岩储集体油气富集的主要因素之一.根据野外露头、岩心、薄片、扫描电镜和成像测井等资料,对基岩储层的发育特征及控制因素进行研究.结果表明:马海东地区元古界基岩储层发育片岩、片麻岩、榴辉岩和角闪岩等4大类9种岩性,裂缝和溶蚀孔等2大类6种储集空间类型,储层物性以低孔-(特)低渗透为主;基岩裂缝是影响溶蚀孔、溶蚀裂缝发育和储层能否获得高产的关键,裂缝的发育程度主要受岩性、构造2个因素的控制,脆性矿物含量高的片岩、片麻岩裂缝发育程度高,断裂级别越大、活动时间越长、距离断裂越近,裂缝发育程度越高;断裂上盘、断裂交汇处是优势储层发育区.

以高分辨率层序地层学和沉积学理论为指导,通过综合运用地震、测录井、岩芯等资料,对马海东构造带古近系下干柴沟组下段进行了高分辨率层序地层学研究.研究区共识别出不同规模的层序界面共6种类型,包括角度不整合、大规模冲刷面、中等规模冲刷面、小型河道下切面、地层样式转换面和沉积环境转换面.在层序界面识别的基础上,将目的层段划分为1个长期基准面旋回(LSC1)、3个中期基准面旋回(MSC1 MSC3)和12个短期基准面旋回(SSC1-SSC12),其中MSC2发育低可容纳空间向上“变深”非对称型(A1)旋回结构,MSC1、MSC3发育高可容纳空间向上“变深”非对称型(A2)旋回结构.建立了研究区层序地层等时对比格架,探讨了各中期层序沉积微相特征和砂体展布规律,结果表明,MSC2中期旋回内发育辫状河道心滩沉积微相,沉积物以砂砾岩、含砾粗砂岩、中细砂岩为主,砂体垂向厚层叠置,横向广泛连通,为研究区最为有利砂体发育层段.

Drilling data and outcrops have both revealed marine source rocks in Qaidam Basin, and gas in claystone and shale of Car?boniferous strata has exhibited great exploration potential. Based on an integrated study of sedimentary environment, organic matter type, abundance, and maturity, combined with outcrop data, drilling data, seismic data and non-seismic data, the authors determined residual thickness of the Carboniferous strata in eastern Qaidam Basin. The results indicate that claystone and shale are mainly concen?trated in the Keluke Formation of tide flat facies in the upper part of Carboniferous strata. There are mainly two kinds of source rocks, namely carbonaceous mudstone and dark-colored mudstone with TOC of 3.08%, and the organic matter is classified as type II-III. Evaluation shows that about 73%of the matured-high matured samples are moderate-good source rocks, and they are mainly scattered in Gaqiu, Ounan, Huobuxun and Delingha sags, forming several thickness centers. Source rocks in Shihuigou area of Ounan sag and Huobuxun sag have most promising high resource potential, and possess favorable conditions for generating shale gas.

柴达木盆地北缘东段石炭系是侏罗系之外的另一套有利生烃层系,针对前人“石炭系为广泛分布于柴达木盆地各残留凹陷”的普遍认识与实际钻探不相符的矛盾,笔者充分利用野外地质调查、钻井、地震、电法等成果资料,通过露头引层、钻井标定、地震相与速度谱识别等方法手段,进行了石炭系顶底界面的追踪解释,重新厘定了柴北缘东段石炭系残留地层分布,并通过平衡剖面恢复分析了自古生代以来的构造演化特征及其对石炭系残留分布的控制作用.结果表明,柴达木盆地东部石炭系平面上残留分布于西段的尕丘凹陷和东段的欧南、霍布逊、德令哈等凹陷,发育尕丘、欧南、霍布逊等多个厚度中心;西段尕西鱼卡凹陷、马海大红沟凸起、大柴旦凹陷、红山—小柴旦凹陷等基本无石炭系残留;印支末期构造运动造成不同构造单元的差异隆升剥蚀是控制石炭系残留分布及其厚度差异的主要因素,燕山晚期和喜山晚期构造运动造成残留分布的分隔性较强.

针对柴北缘大柴旦地区北东、北西向两组逆冲推覆断裂交汇,构造变形极其复杂,构造解析困难的问题,充分利用野外地质调查、地震、重磁电、钻井(孔)等资料,理清了研究区主要断裂体系及其组合特征与展布规律.采用地表和地下构造、浅部和深部构造、地震和非震资料相结合的方法,开展了山前带构造建模研究与构造解析.通过研究,确定了研究区发育NW和近WE向两组断层和盆缘逆冲、盆内逆冲、盆内挤压-走滑等3类断裂体系,平面上具有分区、分带性;建立了盆缘、盆内不同构造变形机制的构造解释模型;共识别出了挤压、伸展和走滑等3大类8种构造样式,明确了构造样式组合模式及其分布规律,理清了研究区“南北分带、东西分区”的构造变形特征;南西-北东向构造演化剖面分析明确了盆缘、盆内推覆构造与盆内反冲构造后展式演化时序及其对中生界残留分布的控制作用.

针对柴东地区中、下侏罗统残余地层分布复杂、原始沉积分布认识不一等问题,充分利用侏罗系野外露头勘查、钻井(孔)、地震等成果资料,通过露头引层、钻井(孔)标定地震以及地震相、低速异常识别等技术手段,明确研究区中、下侏罗统残余地层分布规律;通过野外地质剖面实测、岩心描述,系统研究早、中侏罗世地层沉积特征和充填演化规律,结合中新生代盆—山演化关系,恢复研究区早、中侏罗世古沉积体系.研究结果表明,柴东地区下侏罗统仅分布于红山凹陷,分布面积约为640 km2;中侏罗统分布于红山—小柴旦、尕西—鱼卡、霍布逊和德令哈等6个残留凹陷,尕丘、大柴旦、欧南等凹陷不发育中、下侏罗统.柴东地区早侏罗世表现为冲积扇—辫状河—辫状河三角洲—浅湖—辫状河三角洲的沉积充填演化特征,主要物源来自北方的祁连山,次要物源来自南侧的柴南隆起;中侏罗世处于拗陷沉积阶段,表现为扇三角洲—辫状河三角洲—湖泊的水进半旋回沉积充填演化特征.

中下侏罗统是柴达木盆地东部中深层主力生烃层系,针对研究区前人“早—中侏罗世为广盆沉积、现今残留凹陷均有分布”的普遍认识与实际钻探的矛盾,以及侏罗系有效生烃中心不明确等问题,笔者从地面地质调查、山前冲断带构造建模入手,运用平衡剖面技术研究控凹断裂活动性及盆山演化过程,认为发育持续沉降型、构造正反转型、构造负反转型等三类凹陷;按照“七因素法”恢复了侏罗纪各时期盆地原型,认为柴东地区发育尕西鱼卡、红山—小柴旦、霍布逊、德令哈等4个早—中侏罗世分隔性湖盆,晚侏罗世才发展为统一沉积湖盆,纵向充填表现为早侏罗世伸展弱断陷、中侏罗世伸展拗陷湖沼相、半深湖相以及晚侏罗世挤压拗陷河流冲积相逐层超覆沉积、湖盆不断扩展的特征.中、下侏罗统有效烃源岩残留分布于原始湖盆改造后的尕西等4个持续沉降型凹陷以及鱼卡等两个构造正反转型凹陷.

中、下休罗统是柴达木盆地东部主力生烃层系,针对前人"早—中侏罗世广盆沉积、现今凹陷均残留分布"的普遍认识与实际钻探不相符的矛盾,在充分利用野外地质调查、钻井、地震、电法等成果资料基础上,系统梳理了侏罗系露头层段归属与横向差异,研究了早—中侏罗世原始沉积与残留分布规律,认为研究区早 中休罗世发育鱼卡、红山、德令哈、霍布逊等4个分隔性湖盆,并非广盆沉积,马海古隆起、欧龙布鲁克低凸起等造成原始沉积湖盆分割性较强;中、下侏罗统平面上局限分布于尕西、鱼卡、红山、小柴旦、霍布逊和德令哈等6个凹陷,并且在凹陷带、山前冲断带均有分布,并非与现今凹陷一一对应,欧南、大柴旦等凹陷均不发育中、下休罗统.其残留分布主要受控于早—中侏罗世原始沉积和燕山运动晚期隆升改造两大因素,平面上严格受南祁连、埃南等NW向控山、控凹断裂和马仙等NE向、近EW向调节断裂的双重控制,从而造成现今凹陷之间、控凹断裂上下盘之间中、下侏罗统残留厚度的差异.

从火山岩岩性、岩相特征、储集空间类型等方面研究了腰英台地区火山岩储层特征,分析了火山岩储层物性的影响因素.研究表明:区内火山岩储层主要为流纹岩与凝灰岩,岩相主要为溢流相和爆发相,孔隙类型主要为孔缝组合,储集空间为气孔、溶蚀孔、裂缝等;储层物性影响因素主要有火山岩的岩性、相带、埋深以及构造作用.

The beach-bar sandbodies of the Es4 in Dongying area are of the complex geologic characters of thin sand-in-mud layer and lateral variation large,complex distribution.Separation technology based on seismic semblance background can reveal more reflecting features of thin layers on seismic profile.A scheme of separation technology of semblance background has been built and applied to the reservoir prediction of beach-bar sandbodies of the Es4 in Dongying area.The results show that the seismic data resolution is raised,the more features of thin layers in seismic profile are revealed.This technology can display accurately the reservoir lateral variation in detail on the main target layers and instruct effectively oil and gas exploration in the area.

Diagenesis evolution of deep buried glutenite fans in the Dongying Sag of the Bohai Bay Basin is complicated with multiple influential factors.Reservoir beds are difficult to forecast.Based on microscopic observation of rock thin-sections,intrinsic and extrinsic factors controlling diagenesis evolution are dissected.It has been concluded that,on one hand,there are some advantageous factors influencing reservoir property including sedimentary facies,undercompaction,halite-gypsum pier cement,acidic fluid solution,early stage hydrocarbon infilling,tectonic movement and chlorite film.On the other hand,there are also some disadvantageous factors such as compaction,cementing of carbonate and sulfate,high content of clay minerals,crystallization of high salinity of formation water,and diffuse of dissolved salts.Firstly,middle fan facies,undercompaction,early stage hydrocarbon infilling and chlorite film are favorable for preservation of primary pore space.Secondly,halite-gypsum pier cement and tectonic movement are favorable for fracture development.Thirdly,solution of carbonate rock and feldspar by acidic fluid is the main factor controlling secondary porosity development.All the three elements constitute three-dimensional connected pore-fracture network which is effective to enhance reservoir property in deep buried glutenite.

文章分析了东营北部断裂带中层天然气藏的气体性质、储盖组合类型、温压环境对中层气成藏的影响以及断裂活动对中层气成藏的制约;剖析了三角洲沉积体系在中层天然气成藏中的纽带作用,建立了断裂带中层天然气运聚模式、成藏模式;总结出了中层天然气藏横向分布特征及纵向成藏序列,对于富油盆地断裂带天然气勘探具有很好的指导意义.

Helium content in natural gas reservoirs is very low, usually smaller than 0.1%. Gas helium not only has inmportant industrial values, but also is a major differential mark for the origin of natural gas especially nonhydrocarbons natural gas. In Hua-501 gas reservoir discovered in the Upper Tertiary Minghuazhen Formation (Nm) of Huagou area, the Jiyang Depression, the gas He content is up to 3.08%. The gas components of the gas reservoir is complex. It has not only nonhydrocarbons gas layers dominated by N 2 and CO 2, but also gas layers dominated by CH 4. It is a special gas reservoir of multiple and composite origins. δ 13 C CO 2 is equal to -8.3‰ , and 3He/ 4He is 4.47×10 -6 . These representative indexes reveal that N 2, CO 2, He and other nonhydrocarbons gases are mainly of mantle-source origins. δ 13 C 1 is equal to -48.8‰. This shows that gas CH 4 is organic genetic oil-type gas generated in the Lower Tertiary. The gas reservoir is located in the joint of the Jiyang Depression and the Luxi Uplift. It is controlled by the Gaoqing Fault which is a deep and large rift long activated since the Mesozoic, and is closely related to muti-stage magmatic activities. CH 4 gas layers and N 2, CO 2, He and other nonhydrocarbons gas layers are the products of two stages of accumulation. CH 4 accumulated early, and the accumulation of helium-enriched nonhydrocarbons gases happened within 3Ma from now.

花沟气田是胜利探区惟一的纯气田,天然气资源丰富,其分布复杂而又独具特点.与其他油气田相比,该气田存在多种成因类型的天然气藏,如甲烷气藏、二氧化碳气藏,以及甲烷、二氧化碳和氮的混源气藏.花501井氮气含量中混有高含量的氮气,其含量达到3.08%,国内少见,花4井还钻遇凝析气.文章结合近几年的研究成果,从气源、气藏类型、储集层特征等方面分析了多种类型气藏的成藏规律,有利于指导该区天然气勘探.