There is abundant remaining petroleum in the southwestern Qaidam basin.In the past, more attention was paid to find structural reservoir than lithologic reservoir.In recent years, under the guidance of exploration methods of lithological reservoirs, that is hydrocarbon enriched in depression, accumulated in slope zones, petroleum\|bearing new layer searched, and superposition continuity explored, the breakthrough of petroleum exploration in Hongliuquan slope and Wunan slope of southwestern Qaidam basin was gotten.The discovery of large scale special lithologic reservoir in Yuejin slope was done.Since the low degree of exploration and limited know about lithological reservoir, the exploration of lithologic reservoirs in the southwestern Qaidam basin is still on exploratory stage, and a set of mature and effective methods are not formed yet.Based on exploration achievement of lithologic reservoirs in Qaidam basin, a set of methods fitting for lithologic exploration in the Qaidam basin was gotten, in combination with successful exploration experiences in other basins.These main methods included re\|examination of old wells, classification of sequence stratigraphy, division of sediment system and integrated reservoirs prediction.Good petroleum exploration in Qaidam basin was gotten by these integrated methods with industrial flow for many wells.

柴达木盆地西南区(柴西南)剩余油气资源量巨大，过去勘探思路主要以寻找构造油藏为主，岩性油气藏为辅。近几年来在“围绕富烃凹陷，主攻斜坡区带，寻找新的层系，力争叠合连片”的岩性油气藏勘探思路的指导下，主攻岩性油气藏勘探，在柴西南红柳泉斜坡及乌南斜坡的岩性油气藏勘探均获得突破，跃进斜坡也发现了规模较大的特殊岩性储集体。由于勘探程度和认识上的制约，柴西南的岩性油气藏勘探还处于探索阶段，还没有形成一套成熟有效的技术方法。利用柴西南岩性油气藏勘探实践成果，结合其他盆地的成功经验，总结了一套适合柴西南岩性油气藏勘探的技术方法。这些关键技术主要包括：老井复查评价技术、层序地层划分技术、沉积体系划分技术、储层综合预测技术。综合运用这些技术方法在柴西南的岩性油气藏勘探中已经取得了良好的勘探效果，多口钻井获得工业油气流。

The faulted-topographic break zone is a zone of depositional slope with apparently abrupt-change caused by longtime activities of homo-depositional tectonics.A lowstand fan of the zone mainly consists of underwater alluvial fans,larger turbidite fans, smaller lowstand delta and lowstand fan delta.Lowstand turbidite fans in the steep gradient zone and distant part of the fan-shaped delta are distributed in low terrace,and main body of the fan-shaped delta and the incised-valley fillings are distributed in high terrace while near shore part of the delta and the alluvial fans are developed in higher terrace.During quick subsidence of the depositional base-level,continental incised-channels were formed on the slow slope zone and underwater alluvial fan bodies were developed down below the slope.When the base level was slowly uplift,incised channel fillings were formed on the faulted topographic break zone and down below the zone underwater alluvial fan sandbodies and distant turbidite fan bodies were developed.It is believed that original subtle litho-reservoir could be easily formed in lowstant fans of the faulted-topographic break zone.This kind of reservoir is characterized by its closer distance to source rocks,by well-developed porosity and by superior dredging conditions.

断裂坡折带为同沉积构造长期活动引起的沉积斜坡明显突变的地带,其低位扇主要包括水下冲积扇、大型浊积扇、小型低位三角洲和低位扇三角洲。陡坡带低位浊积扇及扇三角洲远端部分分布于低台阶,扇三角洲主体、下切谷充填分布在高台阶,更高处为三角洲近端部分及冲积扇。缓坡带在沉积基准面快速下降时,其上产生陆上下切水道,其下形成水下冲积扇砂体;当基准面缓慢上升时,在断裂坡折带之上形成下切水道充填,之下发育水下冲积扇砂体和远岸浊积扇砂体。断裂坡折带低位扇易形成原生隐蔽岩性油气藏,此类油气藏具有离源岩近、次生裂隙发育和疏导条件优越的特征。

柴西南地区具周缘前陆盆地性质，新生代以来长期处在近南北挤压应力体制下，主要受到来自南面主动挤压力作用而形成，其演化历史可以分为挠曲拗陷、逆冲、强烈逆冲、表层滑脱褶皱等四个主要演化阶段。文中根据断裂活动强度、基底卷入程度及断裂变形等特征，将柴西南地区断裂分为基底卷入高角度逆冲断层、基底卷入低角度逆冲断层、调节型逆冲断层和高角度反向逆冲断层等四种主要成因类型。基底卷入高角度逆冲断层及基底卷入低角度逆冲断层与造山隆起和盆地沉降具良好的耦合和同步发育关系，断面倾角与昆仑造山挤压强弱相关，对盆地内次级构造单元的形成和沉积具有一定控制作用。调节型逆冲断层，主要起调节挤压块体横向位移和变形差异以及构造枢纽作用，对地层展布无控制作用。高角度反向逆冲断层的级别低，形成较晚，与沉积作用无关。

Based on interpretation of seismic data in western Qaidam Basin，the active models，active time and spatial growth of dominating Cenozoic faults are explored in this paper. The results show that the evolution of faults can be divided into two relatively fast phases： 1)During the deposit time between the Lulehe Fm. and the Upper Xia Ganchaigou Fm.(～54～31 Ma). 2)Since the deposit time of the Xia Youshashan Fm.(～22 Ma～present). The latter phase was more robust，especially since～8 Ma(since the deposit time of the Shizigou Fm.)，the NWW faults begin to active significantly which indicates the most drastic tectonic collision process. Quantitative analysis of the proxy of the growth faults also correspond with the two phases. Together these indicate that the collision between Indian and Eurasia continents has a twostages feature after～55 Ma they will provide some new convincible evidence for the multistages uplift of the NE Tibetan Plateau. 

基于主干地震剖面的解释结果，本文探讨了柴达木西部地区新生代主控性断裂的活动模式、活动时间及空间演化过程。结果表明，断裂演化明显存在两个大的旋回：路乐河组—下干柴沟组上段沉积期间（约54～31 Ma）和下油砂山组沉积至今（约22 Ma至今）； 其中第2个构造期断裂活动强烈，尤其是狮子沟组沉积以来（约8 Ma至今），中部及北部区域北西西向断裂开始大规模逆冲活动，反映了盆地晚期强烈变形过程。断层生长指数定量分析结果与其空间演化过程相吻合，共同记录了印度—欧亚板块碰撞远程效应控制下的柴达木盆地在新生代具有阶段性变形特征，从而为青藏高原东北部分阶段隆升模式提供了新的证据。

The viewpoint that slope break belt developed both in the marine basin and the nomarine rift basin played important controlling effect on sequence and sediment frameworks has got extensive concern and been widely accepted in recent years. According to the combination characteristic of seismic profiles and sedimentary microfacies，studies on the Triassic Yanchang Formation in the Ordos basin show that sedimentary slope break belts were also developed in the large depression lacustrine basin, and could be clearly recognized either in the deep water or in the shallow water. Deposits of the deepwater gravity flows such as the sandy debris flows and the turbidity flows were mainly controlled by the slope break belt in deep water, whereas deposits of tractive current like subaqueous distributary channels in the deltafront were controlled by that in the shallow water. Further studies suggest that, except for sandbody origin types, the deepwater and shallowwater sedimentary slope breaks also have obvious controlling effect on thickness, plane distribution, and physical properties of the sandstones.  In addition, it is suggested that petroleum distribution was also controlled to a certain extent by the slope break belt. Although oil reservoirs can be found everywhere in the Yanchang Formation, most of the larger lithologic reservoirs are located either below the slope breaks or in the LST(lowstand systems tracts) sandstones neighboring the sequence boundary, or controlled by both of the slop break belt and the sequence boundary. 

在海相盆地和断陷湖盆中都发育坡折带，并对层序和沉积起重要控制作用，这一观点已得到广泛关注并被普遍接受。利用地震反射剖面及沉积微相组合特征，对鄂尔多斯盆地三叠系延长组的研究表明，在大型坳陷湖盆中也发育坡折带，按照在湖盆中的所处位置，可明显划分出深水沉积坡折与浅水沉积坡折两类，前者位于三角洲坡型前缘深水区，后者位于三角洲台型前缘或三角洲平原附近。研究表明，深水沉积坡折主要控制砂质碎屑流与浊流等深水重力流砂体沉积，浅水沉积坡折主要控制正常牵引流三角洲前缘水下分流河道砂体沉积。进一步研究认为，除对砂体成因类型具有控制作用外，深水与浅水沉积坡折对延长组中部砂体厚度变化、平面展布形态以及砂体物性变化也具有明显控制作用。在此基础上，文章还讨论了坡折带对油气分布的控制作用，认为延长组油气分布受坡折带与层序格架双重控制，坡上/坡下、高位域/低位域/水进域均能成藏，但规模较大的油气田大多数都位于层序界面附近，要么受坡折带控制，要么受低位域砂体控制，或者二者共同控制。

The slope breaks are developed widespread in Jurassic large down warped lake basin, the Northwestern Area, Junggar Basin. Their genetic types can be divided into fracture slope break, bending slope break, sedimentary slope break and erosional slope break. For their showing mutual grades characteristics along source area direction, they also can be divided into basin margin slope break and inner basin slope break according to their natural geographical positions.The genetic mechanism of the slope breaks includes deep seated thrust structure, inherited paleohigh and interior basin secondary fault,etc., and the scale of slope breaks intimately relates with the size and the period of tectogenesis. Because of the variance of tectonic activity in different period and district range, the slope breaks formed by tectonic have multi period, episode, differential motion, inherited and invert characteristics. The slope breaks obviously control the stratigraphic overlap, the longitudinal lithologic combination and the longitudinal and lateral distribution of depositional systems. So, we establish a reasonable pattern that the slope breaks control nonstructural traps and guide the regional exploration of nonstructural traps, which has the significance to further prospect for large scale nonstructural traps and traps group.

准噶尔盆地西北缘侏罗纪坳陷湖盆坡折带十分发育,具有断裂坡折带、挠曲坡折带、侵蚀坡折带和沉积坡折带等多种成因类型。坡折带在顺源方向具有多级特征,把坡折带按地理位置的差异分成盆缘坡折带和盆内坡折带。其中深部逆冲构造、继承性古隆起、盆内次级断层活动等构造运动是坡折带发育最主要的成因机制,坡折带发育规模与构造活动的大小、期次息息相关。由于构造在不同时期不同地域范围内其活动强度的差异,所形成的坡折带具有明显的多期、幕次性、差异活动以及继承与转化性等特征。同时坡折带在对地层超覆叠置、岩性纵向组合以及沉积体的纵横向展布上具有重要的控制作用,以此为基础建立了坡折带控制非构造圈闭的模式,对进一步寻找大规模的非构造圈闭或非构造圈闭群具有参考意义。

With the increasing need for exploration and development, lithologic reservoir has become an important domain for oil and gas exploration in southwestern Qaidam Basin. However, due to multiphase tectonic overprinting activities, the distribution of lithologic reservoir in southwestern Qaidam Basin is indistinct and the next exploration area is indefinite. Through this study, seismic activity is found to be very intensive in southwestern basin due to the influence of basin edge and northwestern second order fault. Seismites related to earthquake are found in deep and shallow beds. Lots of deformation structures are found, such as small step faults, liquid sandstone dikes, vibrating liquid curling structures, sand volcanos, flame structures, pseudoconcretions, seismite sand pillows, seismite sand ball structures, pinch and swell structures, etc. Some rock types are also observed, such as folding seismites, cracked seismites, autoclastic breccias, intraclastic subbreccias. In fact, these smites can greatly increase the permeability of reservoir, which provides a new perspective for oil and gas exploration and development. More importantly, the paleoearthquake is a significant event that triggers seismites, initiates a landslide at the delta front easily, and creates some sediment phenomenon, such as slump fans and turbidities. This kind of reservoir will become a new growth point of reserves. With this thought, by seismic pre-stack multi-attribute prediction and advanced pre-stack AVO inversion prediction, slip blocks are found on Yuedong ramp region in southwestern Qaidam Basin and deposition model is built correspondingly. This might be a breakthrough of previous exploration ideas of \"search for oil around sags\" in this area. It is clearly put forward that paleosag is still an important exploration domain for lithologic reservoirs.

随着勘探和开发的需要，岩性油气藏成为柴达木盆地西南区石油勘探的一个重要领域，然而由于受多期的构造叠加改造，致使柴西南区岩性油气藏分布规律不清，勘探接替领域不明确。笔者通过研究发现，由于受盆缘及其北西向二级断裂的影响，盆地西南区地震活动强烈，深、浅层均发现一系列与地震有关的震积岩，可见阶梯状小断层、液化砂岩脉、振动液化卷曲变形构造、砂火山、火焰状构造、假结核、震积砂枕、震积砂球构造、串珠状构造及震褶层等原地震积岩的软沉积物变形特征，另外可见地震引起的重力滑塌或泥石流形成的滑塌构造和角砾岩化变形特征，诸如震裂岩、震塌岩、自碎屑角砾岩、液化角砾岩、内碎屑副角砾岩等异地震积岩。事实上这些震积岩能够极大地改善储集层渗透性,使渗透率大幅度增加,为油气勘探和开发提供了新的视角和领域。更为重要的启迪是形成震积岩的古地震具有重要的触发机制，很容易引起三角洲前缘相的岩性发生滑塌，进而形成滑塌扇、浊积等一系列沉积现象，这种储集体将成为油田储量增长的新亮点，本着这种思想，笔者通过叠前地震多属性的预测及先进的叠前AVO反演预测，在柴西南区跃东斜坡带发现这种滑塌体的存在，并建立了相应的沉积模式图。这样将可能突破了以往该区“环凹找油”的勘探思路，明确提出了古凹陷区仍然是柴西南区寻找岩性油气藏的一个主要领域。

Slope break is a geomorphologic concept, which refers to a zone where there is an abrupt change in topographic slope.Slope break can develop not only in sedimentary basins,but also in denudation areas. It would be of stratigraphic sequences in marine sedimentary basins shows that the type I sequences in a basin with shelf slope break margin or growth fault (faulted slope break)margin,unconformity and incised valley can be formed above the slope break,while basin-floor fan,slopee fan and other aktian deposits,as well as lowstand wedges can be deposited below the slope break during the lowstand.This sedimentary system constitute a typical LST sediments.The concept of structural slope break has been advanced in recent years in the rift lacustrine basins. Structural slope break refers to the sedimentary slope break caused by the long activity of syndepositional structures. The structural slope break, on the one hand, has a strong impact on the accommodation and deposition in the basin, and on the other hand, controls the spatial distribution of the sedimentary facies.There are various kinds of faulted slope breaks,such as salient-gentle slope margin, gentle slope-subsag margin,salient-steep slope margin, steep slope-subsag margin, etc.And it has been further clarified that incised valleys, lowstand river-delta and lake-floor fans can be developed in the LST in the lake basin, which would constitute the potential reservoirs in deeper part in the basin.The distribution of these sediments have clearly been controlled by the structural slope breaks in the basin margin.The study of the Paleogene in Dongying sag shows that there are multistage slope breaks ,such as faulted, flexural, depositional and erosional slope breaks in the half graben-like rift lacustrine basin. The large syndepositional faults that act as the boundary of tectonic subunits, such as salient, slope (fault bench) and subsag, would often become faulted slope breaks.As a result,there will be various types of faulted slope breaks successively developed from the steep slope to gentle slope belts,including salient-steep slope, steep slope-subsag,salient-gentle slope, gentle slope-subsag margins.Nearby these slope breaks,some smaller syndepositional faults can become auxiliary faulted slope breaks and constitute various complex plane combination patterns. Above and below the faulted slope break on the edge of salient may develop erosional slope break. Flexural slope break are mainly associated with syndepositional anticline and nose,which are developed best on both limbs of central anticline-belt and on delta front.The most typical depositional slope break is that developed along the long-axis on Dongying delta front.Faulted slope break controls the development of lowstand fan and compound lithologic-structural traps, depositional slope break controls the distribution of lowland fan,highstand slumping turbidity fan and lithologic traps,while flexural and erosional slope breaks control not only the development of sandbody,but more apparently control the development of stratigraphic overlap, truncation wedge-out and stratigraphic traps.Finally, different kinds of slope breaks developed in the rift lake basin distribute extensively and appears multistage slope breaks.The slope break controls significantly the development of stratigraphic depositionnal and non-structural traps. Combination of oil and gas reservoirs usually occur near the slope break.A thorough study of the genetic type and distribution of slope breaks and their control on sedimentary facies and reservoirs in the maturely explored area as Dongying sag would certainly establish a vast domain in the study of rift basins in eastern China.

对东营凹陷下第三系的研究表明,在箕状断陷湖盆中发育有多级坡折带,其成因类型有断裂坡折带、挠曲坡折带、沉积坡折带和侵蚀坡折带。作为凸起、斜坡(断阶)和洼陷等次级构造单元之间分界线的大型同沉积断裂往往形成断裂坡折带,从而从陡坡带到缓坡带依次发育有凸起-陡坡边缘、陡坡-洼陷边缘、凸起-缓坡边缘、缓坡-洼陷边缘等断裂坡折带。在这些坡折带附近的较小的同沉积调整断层可以形成更次级的断裂坡折,并形成各种复杂的坡折平面组合样式。在凸起边缘断裂坡折带的上下有时会形成侵蚀坡折带。挠曲坡折带主要与同沉积背斜、同沉积鼻状构造相伴生,其中在中央背斜带两翼、陡坡带的滚动背斜带和缓坡带的鼻状构造的两翼最为发育。沉积坡折带发育在大型三角洲前缘,以沿长轴发育的东营三角洲前缘最为典型。断裂坡折带控制了低位扇体以及岩性-构造复合圈闭的发育,沉积坡折带控制了低位扇、高位滑塌浊积扇以及岩性圈闭的展布,而挠曲坡折带和侵蚀坡折带除了对砂体有控制作用外,更突出地表现为对地层超覆、削蚀尖灭线以及对地层圈闭发育的控制。坡折带附近是非构造油气藏发育的有利场所,进一步勘探的潜力巨大。

Qaidam Basin is a superimposed basin developed under the different tectonic backgrounds during Cenozoic. Because of multi stage tectonic activities, multiple sets of rift system developed. The Wunan area in the southwestern margin of the Qaidam Basin was intensely affected by a series of faulting movement of Neocene in the north of Kunlun Mountain, and developed seismite presented serious seismic related soft sediment deformation structures. The Neocene soft sediment deformation structures in the Wunan oilfield consist of load casts, flame structures, pillow structures, ball structures, pseudonodules, pillow beds, liquefied sandstone vein, liquefied mudstone vein, water escape structures, micro fault, micro fracture, pinch and swell structures, micro corrugated lamination. Seismites can be subdivided into many types, such as seismic corrugated rocks, shattered rocks, seismic collapse rocks and autoclastic breccias. When earthquake was active, a great amount of micro fractures formed and connected with original pore．Though the porosity of reservoirs would not be improved greatly, the permeability of reservoirs can be improved obviously. Seismites, especially the shattered rocks and seismic breccias, are potential reservoirs and will become new exploration areas in the near future．

柴达木盆地为一新生代以来形成的叠合盆地，由于多期构造活动，盆内形成了多组断裂系统。受新近纪昆仑山北侧断裂活动的影响，盆地西南缘乌南地区地震活动强烈，发育一系列与地震有关的震积岩，形成多种类型的与地震活动有关的软沉积物变形构造。乌南油田新近系的软沉积物变形构造主要包括重荷模、火焰构造、震积砂枕、砂球构造、假结核、枕状层、液化砂泥岩脉、泄水构造、层内错断、地裂缝、串珠状构造、微褶皱纹理等。本区震积岩的岩石类型主要包括震褶岩、震裂岩、震塌岩、自碎屑角砾岩等。地震活动使岩层产生大量的微裂缝，裂缝沟通了原有的孔隙。尽管储集层孔隙度没有大幅度增加，但能够极大地改善储集层渗透性，使渗透率大幅度增加。震积岩特别是震裂岩和震碎角砾岩是一种潜在的油气储层，为油气勘探和开发提供了新的视角和领域。

A great deal of soft-sediment deformation structures with seismite characteristic were found in the lacustrine strata of the Pleistocene in the southwestern margin of Qaidam Basin.Soft-sediment deformation markers mainly include liquefied sandstone(mudstone)vein，liquefied breccia，load structure，ball-pillow structure，liquefied convolute deformation structure etc .，and the syn-seismic structure deformation markers were also developed including large-scale syn-seismic fault，seismic fissure，syn-fold.The discovery of seismites in the southwestern Qaidam Basin indicates that tectonic movements were frequent and intense since the Pleistocene along the northern margin of the Kunlun Mountain and in the Qaidam Basin.The seismites made it possible to study the tectonic activities since the Pleistocene which has important significance for the study of the Qinghai-Tibet Plateau，basin-mountain coupling and paleo-earthquakes.

在柴达木盆地西南缘更新统湖相地层中发现了大量具有震积岩特征的软沉积物变形构造，层内发育有液化砂（泥）岩脉、液化角砾岩、负荷构造、火焰构造、球—枕状构造、液化卷曲变形层等一系列软沉积物变形标志，此外剖面内还发育了大型同震断层、震裂缝、同震褶皱等一系列同震构造变形标志。该区震积岩的发现表明，更新世以来昆仑山北缘及柴达木盆地地区仍处于频繁而强烈的活动状态，通过震积岩层可以更加深入地了解柴达木盆地更新世以来构造活动状况，这对于研究青藏高原隆升及其盆山耦合、古地震活动等都有着十分重要的意义。