The Z Block is located in the eastern part of the Yishan Slope in the Ordos Basin, adjacent to the western margin of the Jinxi flexual fold belt and the volcanic rock massif to the west. The block has a thick and well-developed coal-bearing stratum in the Paleozoic Era, and exploration breakthroughs have been made in the multi-layered strata of the Paleozoic Era, indicating great exploration potential. However, the complex structural and enrichment conditions caused by the compression of the Jinxi flexual fold belt and the Zijinshan volcanic rock massif have seriously hindered the understanding of the structural, reservoir, and enrichment laws of the coal series gas, which has severely constrained the exploration and development progress of the area. Therefore, based on the comprehensive control factors of structure, reservoir, and magmatic thermal effects, this study explores the coal series gas accumulation model in this area. The research results show that: 1) The coal seam in the Z Block is well developed, with sufficient gas supply, and the sandstone reservoir in the coal-bearing stratum of the Paleozoic Era is well developed, providing a good foundation for the accumulation and enrichment of coal series gas; 2) Influenced by the Jinxi flexual fold belt in the east and the volcanic activity in the west, the block shows a two-uplift and one-depression feature, and the central gentle zone is a favorable area for coal series gas exploration; 3) Three sets of faults are developed in the Paleozoic Era, which play a controlling role in the vertical accumulation of tight gas in the area. The conclusion is that the central gentle zone of the Z Block is mainly composed of coalbed gas and tight sandstone gas, and its accumulation and enrichment are controlled by multiple factors such as structural evolution, magmatic activity, and sedimentary reservoir distribution. The research results provide a direction for the exploration of coal series gas in the area.

Canyons in carbonate depositional settings, as important elements of the source-to-sink system, remain poorly studied compared to those in siliciclastic depositional environments. The latest high-resolution three-dimensional seismic data, well logs, and core data at the eastern edge of the Precaspian Basin are used to investigate the geomorphology, infillings, and depositional process of a unique carbonate-filled canyon in the Carboniferous KT-II formation parallel to the carbonate platform, which is distinct from other slope-perpendicular canyons. The canyon has a total length of more than 52.3 km with a nearly N-S orientation and an S-shaped geometry, and the whole canyon can be divided into three segments by two knickpoints. The slope-parallel orientation of the canyon is mainly controlled by the palaeogeomorphology and reverse faults. Due to the collision of the Kazakh and European plates in the early-middle Visean (early Carboniferous), the canyon was formed in a northern tilted, elongated, and restricted palaeotopographic feature between uplifts. The development of reverse faults related to tectonic movement controlled the variations in the width of the canyon and the positions of the knickpoints. Tectonics controlled the orientation and formation of the canyon, while sedimentary processes contributed to its infilling. The well-seismic tie analysis indicated two distinct periods of the canyon fillings, Ss1 and Ss2, which were separated by a second-order sequence boundary. The lower part contained sediments supplied by both sides of the canyon through channels or gullies, and the upper part was dominated by a carbonate platform that prograded from the eastern side of the canyon. The evolution of the canyon can be subdivided into three stages. The increasing stage was mainly characterized by significant upslope erosion through headward retrogressive mass failures in the slope-parallel confined negative relief to form the canyon during the lowstand system tract of Ss1. Subsequently, in the early filling stage, the carbonate factory was productive during the highstand, and massive excess carbonate sediments were transported into the adjacent canyon by channels or gullies on both sides and deposited. The canyon was basically filled, and the morphology became much gentler. During the subsequent late filling stage, the carbonate platform was flooded again during the highstand, and the production rates of the carbonate factory greatly increased. The lateral progradation of carbonate platforms accelerated on the canyon of the early filling stage and further into the inner sag.

鄂尔多斯盆地东缘石楼北区块的二叠系山西组S23亚段是致密气勘探的重点层系,区块内钻井较少,钻探程度低.S23亚段储层薄且致密,非均质性强,岩性横向变化快,常规地震反演方法储层预测效果差,严重制约了致密气的勘探.为此,综合利用钻、测井资料和三维地震数据,开展古地貌、地震属性、测井相分析,刻画了石楼北区块S23亚段各沉积微相的展布;在此基础上开展了基于相控的地质统计学反演预测砂体展布,预测结果与钻井一致性高.研究成果为石楼北地区资源量的预测和下一步钻井部署提供了依据.

浅水三角洲是沉积学和油气勘探开发领域的热点,目前研究主要集中在大型坳陷型盆地内,部分学者研究证明在断陷湖盆萎缩期或裂陷初期也存在浅水三角洲沉积,但研究较为薄弱.本文利用岩心、测井、地震以及分析化验资料,对Muglad盆地研究区内Aradeiba组浅水三角洲的沉积有利条件、沉积特征以及垂向演化特征进行了深入剖析,结合湖平面变化、物源供应等情况,建立其沉积演化模式.研究区在Aradeiba期构造相对简单,基底起伏不大,地势宽缓;古气候温暖潮湿,利于母岩区风化作用的进行,物源充足;古水体水浅动荡,具备形成浅水三角洲的有利沉积条件.综合组分、沉积构造、岩心旋回及粒度、录井等多方面资料,分析研究区内发育的浅水三角洲.取心段由多个小型冲刷面或沉积间断面分隔的正韵律叠加而成,每个正韵律下部为中-粗砂岩沉积,发育强水动力沉积构造,顶部则多为杂色泥岩.石英含量很高,分选好,砂岩粒度概率曲线以两段式为主,跳跃总体含量较高,也有一定量的悬浮总体,反映了浅水牵引流的沉积特点.根据Ara-deiba组岩心相及测井相特征,研究区内主要为浅水三角洲前缘沉积.延伸远并且多分叉的水下分支河道发育,表现出高幅箱型-高幅钟型-中高幅薄箱型等多种测井相类型;河口坝在测井曲线上呈中高幅漏斗型.Aradeiba组自上而下划分为5个小层,结合测井解释成果、岩心相与测井相特征以及砂岩含量图,对不同小层的垂向沉积特征分析,发现不同小层主体沉积微相发生明显演化.综合湖平面、构造演化等因素,提出Unity凹陷Aradeiba组各小层沉积演化模式.裂陷初期,湖平面上升,第5小层主要为远砂坝、席状砂沉积;随着断裂活动加强,物源充足,浅水三角洲规模增大,第4、第3小层分别主要为水下分支河道、河口坝沉积;第2小层沉积时,湖泊水动力增强,分支河道发生明显席状化;伴随湖平面快速上升,第1小层主要为浅湖相泥岩披覆沉积.以上分析,对于加深Muglad盆地的沉积学认识并拓展油气勘探的领域和范围具有一定的指导意义.

When reservoir prediction is carried out in a deep-water carbonate-distributing area without any exploration well,it is commonly not only easy to judge reservoir-free bioherms erroneously as real organic reefs only according to the mound seismic reflection configuration that is considered as the proof of reef existence but also easy to ignore the shoal flats without the feature of mound seismic reflection which are likely to be reservoirs.Contrasting seismic reflection with seismic velocity in feature,it is shown that some deference and correlation exist among reefs,bioherms and shoal flat bodies.A reef is characteristic of the mound reflection configuration with high velocity,and a bioherm is of same mound reflection configuration but with low velocity while a shoal flat(body) is of high velocity without the mound reflection configuration.Based on such features,a new method is built for predicting reef reservoirs and shoal flat reservoirs in deep-water areas.This method is applied to predict once more the middle Miocene Meishan carbonate reservoir in some deep-water area of Qiongdongnan Basin.The re-prediction gives a different result that a large part of reefs that were predicted before into "reefs" are reclassified into bioherms and meanwhile shoal flats with a such large area nearly as the distribution area of the reefs are unexpectedly discovered.It is proved that it is an accurate method for predicting carbonate reservoirs in deep-water area.