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271.
In this study, X-ray diffraction, N2 adsorption (N2A), and mercury intrusion (MI) experiments were used to investigate the influence of acid treatment on pore structure and fractal characterization of tight sandstones. The results showed that acid treatment generated a certain number of ink-bottle pores in fine sandstone, aggravated the ink-bottle effect in the sandy mudstone, and transformed some smaller pores into larger ones. After the acid treatment, both the pore volume in the range of 2–11 nm and 0.271–8 μm for the fine sandstone and the entire pore size range for the sandy mudstone significantly increased. The dissolution of sandstone cement causes the fine sandstone particles to fall off and fill the pores; the porosity increased at first but then decreased with acid treatment time. The fractal dimension obtained using the Frenkel-Halsey-Hill model was positively correlated with acid treatment time. However, the total fractal dimensions obtained by MI tests showed different changes with acid treatment time in fine sandstone and sandy mudstone. These results provide good guiding significance for reservoir acidification stimulation.  相似文献   
272.
<正>Exploration at home and abroad have proved that oil and gas preserved in mud-shale reservoir is frontier for oil industry,marine mud-shale in America and marine/terrestrial mud-shale in China both exhibited good potential(Zhang et al.,2008;Nie et al.,2009;Li et al.,2010;Dong et al.,2011;Jiang et al.,2012).Although study on shale gas started late in China with many topics  相似文献   
273.
The Bohai Bay Basin contains many depressions with varying degrees of hydrocarbon enrichment associated with the geological structures of different depressions. This study discussed the relationship between the geological structures and hydrocarbon enrichment of the depressions in the Bohai Bay Basin. Based on the Paleogene strata distribution and the length to width ratio of different depressions, their geological structures are divided into three types in plan-view: open(length/width 2), narrow(length/width 4) and transitional types(length/width 2–4). In cross section, the geological structures can be divided into dustpan I, dustpan II and double-faulted types. Based on tectonic evolution and sedimentary characteristics, the depressions are classified into early-formed, inherited and late-formed categories. Generally, narrow depressions are mainly located in the northeast and southwest of the Bohai Bay Basin, while open depressions are dominantly distributed in the central area of the basin; late-formed depressions are mainly around the Bohai sea area, and early-formed depressions are mostly located in the periphery of the basin. Geological structures of the depressions control the formation of the source, reservoir and cap rocks as well as hydrocarbon accumulation setting, and further influence the pay zones and oil-bearing sequence. In detail, dustpan II and doublefaulted depressions mainly have A-type sags, which often possess better hydrocarbon generation conditions than dustpan I ones; hydrocarbons in open dustpan II depressions tend to accumulate in the central uplift areas or buried hill, while those in narrow dustpan I depressions always accumulate in gentle slope belts. The oil-bearing sequence for different evolutional depressions corresponds well with the sedimentary strata of the main development stages of depressions. In early-formed depressions, hydrocarbons are mainly enriched in deeply buried reservoirs, while in late-formed depressions hydrocarbons are abundant in the relatively shallow traps. In summary, most inherited and late-formed dustpan II depressions are enriched in hydrocarbons due to their extensive source rocks and good source–reservoir–seal assemblages, whereas dustpan I and early-formed depressions are relatively poor in hydrocarbons.  相似文献   
274.
The fibrous mineral veins are widespread in mudstones. According to the different microscopic morphology of the minerals, the fibres can be divided into stretched crystals, elongate-blocky crystals and the very fibrous crystals. Veins can also be classified according to the growth direction of these crystals into stretched veins, syntaxial veins and antitaxial veins. The resulting texture in the vein depends on the morphology of the fracture surface, the width of the fracture and the growth habit of the vein forming mineral. The crack-seal mechanism can only interpret the formation of the stretched crystal veins and the elongate-blocky crystal veins, and the antitaxial well-developped fibrous veins form without fracturing and the growth competition is inhibited during the rock deformation, which implies that the nutrient transport is by diffusional flow transport. Horizontal crack is the primary condition of the formation of the antitaxial bedding-parallel fibrous calcite veins in muddy hydrocarbon source rocks. The formation of the horizontal crack which caused by the abnormal high pressure can enhance the hydrocarbon generation efficiency and has a great effect on the rate and direction of hydrocarbon migration in the local. The presence of the veins indicates the hydrocarbon fluid can migrate laterally along the layers. The antitaxial bedding-parallel fibrous calcite veins in muddy hydrocarbon source rocks can be the sign of the generation and migration of hydrocarbon under the abnormal high pressure condition in petroleum-bearing basins.  相似文献   
275.
276.
通王断裂带沙河街组油气成藏主控因素研究   总被引:1,自引:0,他引:1  
通王断裂带地区位于济阳坳陷东营凹陷南斜坡东部,沙河街组是本区的主要含油层系。通过烃源岩分析、储集层类型划分、孔隙流体动力场的描述、优质输导体系类型及断裂构造特征的研究,认为牛庄洼陷烃源岩主要为沙四上和沙三段深湖相一半深湖相暗色泥岩、油页岩,油气以生油洼陷为中心,呈环状或半环状分布;沙三段大型三角洲相储集砂体、沙四段中上部的滨浅湖近岸砂坝、远岸砂坝和席状砂岩储层是主要储集层类型;砂体一断层类输导体系是本区优质输导体系,牛庄洼陷北部发育的高压型复式温压系统,使油气顺着断层、砂体向南部通王断裂带常压常温和常压高温区运移。通王断裂带的油气藏主要是受断裂控制的构造油气藏,王家岗油田往西的中浅层是断层类油藏的有利地区,王家岗地区北部和陈官庄地区的西北部,是沙三段隐蔽油气藏以及断层-岩性复合型油气藏勘探的有利勘探地区。  相似文献   
277.
济阳坳陷阳信-花沟-平南地区CO2气藏的储层和盖层   总被引:8,自引:0,他引:8  
程有义 《沉积学报》2001,19(3):405-409
济阳坳陷是渤海湾盆地的一个次级构造单元,其中部阳信-花沟-平南地区是主要的二氧化碳 (CO2 )气藏产出区。该地区CO2 气藏的储层主要有下古生界海相碳酸盐岩、下第三系湖相碳酸盐岩和三角洲相砂岩、以及上第三系河流相砂岩。下古生界碳酸盐岩储层分布于其北部潜山带,储集空间以构造裂缝和溶蚀孔隙为主。下第三系湖相碳酸盐岩储层分布于平方王地区的沙四和沙一段。下第三系三角洲相砂岩储层主要发育于高青-平南、林樊家和阳信等地的沙河街组。上第三系河流相砂岩储层分布十分广泛,但总体来讲,其北部地层砂泥比 (5 0 %~ 70 % )较高,砂岩单层厚度 (2 0~ 40m)大,孔隙度大,渗透率高;而南部地层砂泥比小,砂岩单层厚度薄,孔隙度小,渗透率低。研究区CO2 气藏的盖层以泥质岩类为主,致密砾岩次之。它们均为有效盖层。沙三段、沙一段、馆陶组上部至明化镇组下部泥质岩集中段是CO2 气藏最重要的三大区域盖层。沙四段致密砂砾岩盖层主要分布于八里泊残丘潜山的顶部,构成潜山圈团的盖层,其渗透性很低。与烃类甲烷气藏相比,两者的储层类型基本相同,但对于盖层而言,由于CO2气分子半径较烃类甲烷气分子半径大,因而CO2 气藏对盖层的要求比烃类甲烷气藏低。  相似文献   
278.
辽河西部凹陷沙三段浊积岩储层中钙质夹层研究   总被引:29,自引:0,他引:29  
本文阐明了辽河西部凹陷高升、兴隆台、曙光和冷东四个地区沙三段浊积岩油气储层内的钙质夹层识别标志,定性、定量地揭示了它在剖面和平面上空间分布规律,探讨了它的成因机制,指出了钙质胶结作用和钙质夹层对储层性质与油气分布的重要影响。  相似文献   
279.
《Applied Ocean Research》2007,29(1-2):80-85
An approach by which the scour depth around a spherical body and the self-burial depth of such a body in random waves can be derived is presented. Here the formulas for scour and self-burial depths of a spherical body by Truelsen et al. [Truelsen C, Sumer BM, Fredsøe J. Scour around spherical bodies and self- burial. ASCE J Waterway Port Coast Ocean Eng 2005;131(1):1–13] for regular waves are used. They are combined with describing the waves as a stationary Gaussian narrow-band random process to derive the scour and self-burial depths in random waves.  相似文献   
280.
根据地化指标及测井资料分析了准噶尔盆地西北缘克-乌断裂带断理解活动以及断裂带岩性(火山岩、碎屑岩)对油气分布的影响。认为断裂活动及断裂带岩石物性对油气分布具有明显控制作用,在断裂活动期间,断裂带为油气运移提供良好通道,成熟度较低的油气通过断裂带运移至上覆地层;断裂活动平静期,断裂带碎屑岩对油气起封闭作用,火山岩断裂带仍是油气运移通道。成熟度较高的油气经过火山岩运移到断裂带内缘聚集成藏,在断裂带外缘,由于碎屑岩封闭作用及成熟度料高油气的排替作用,油气成熟度呈现“上低下高”的分布格局。  相似文献   
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