Production of gas from coal seams in the Upper Silesian Coal Basin in Poland in the post-injection period of an ECBM pilot site     

Frank van Bergen  Pawel Krzystolik  Niels van Wageningen  Henk Pagnier  Bartlomiej Jura  Jacek Skiba  Pascal Winthaegen  Zbigniew Kobiela 《International Journal of Coal Geology》2009,77(1-2):175-187

A pilot site for CO₂ storage in coal seams was set-up in the Upper Silesian Coal Basin in Poland in the scope of the RECOPOL project, funded by the European Commission. About 760 tons CO₂ were injected into the reservoir from August 2004 to June 2005. Breakthrough of the injected CO₂ was established, which resulted in the production of about 10% of the injected CO₂ in this period. This paper reports on activities performed under the European Commission project MOVECBM that aimed at the assessment of the storage performance of the reservoir in the follow-up period, i.e. whether the injected CO₂ was adsorbed onto the coal or whether it was still present as free gas in the pore space. The injection well was used for this purpose, as the production well had to be abandoned for permitting reasons. Several operational periods can be defined between the last injection in June 2005 and the abandonment of the well in October 2007. In the first period the well was shut-in to observe the pressure fall-off, from about 15.0 MPa at the wellhead after the last injection until about 4.5 MPa at the end of 2005. This pressure fall-off curve showed that the reservoir permeability was very low. This seemed to confirm the observed swelling of the coal during the injection period. In the first months of 2006 the pressure at the wellhead was decreased by releasing gas in a controlled way. The amount and composition of the gas were measured. As a result of the pressure reduction, the well flooded with water. A production pump was placed on the former injection well, enabling active production from the coal from March to September 2007. Results of these operations showed that whereas the gas production rates were as expected based on the experience with the production well, the water production was remarkably low. This could be related to permeability issues or, alternatively, indicate a drying effect of the CO₂ in the reservoir. Further, the gas composition showed a predominance of CO₂ over CH₄ during the gas release that changed gradually into a predominance of CH₄ over CO₂ during the production phase. Although stabilization was not reached within the given production period, the composition approached a 60% methane, 40% CO₂ ratio. This indicates that the exchange of these gases is more complex than often envisaged. After removal of the pump the well was filled with water, which ceased the gas release. This indicates that the pressure in the reservoir was back to its original, hydrostatic, state. As the total volume of CO₂ produced was only a fraction of the amount that was injected, it can be concluded that the CO₂ was taken up by the coal and is currently adsorbed. This gives confidence in the long-term stability of the injected CO₂.  相似文献   

辽宁沿海早、中期全新世海进中的一次海退事件探讨          下载免费PDF全文

方晶  武亚芳  李瑞武  周江  康玲玲  柴锐  马楠 《地学前缘》2009,16(2):396

通过分别对辽东半岛东侧大洋河平原中部的D65孔岩心做连续的硅藻分析,以及对辽东半岛西侧的长兴岛八岔沟古泻湖平原B3孔、下辽河平原的机械钻孔X33及手动钻孔X11和X21等钻孔岩心做连续的粘土混浊水电导率测定,得到各岩心的硅藻图谱/或粘土混浊水电导率图谱。显示出在这些海岸平原均有厚度在6m以上的海相层存在。表明全新世海侵时海水达到并长期占据这些海岸平原。同时还显示在这些海相地层的5～7m深处,普遍存在一层陆相或海陆交互相地层,通过对各地点已有的14C年代数据分析,推测这层陆相层或海陆交互相地层应该形成于全新世海面上升的早全新世—中全新世时期。表明全新世海进期当中,辽宁沿海普遍存在一次海退地质事件。从下辽河平原样品的14C测年数据,推测这次海退时期大致在9300～8000aB.P.(校正年)。  相似文献   

Midale油田奥陶系白云岩储层格架与油藏特征     

蒲仁海  卿海若 《沉积学报》2004,22(2):234-243

综合三维地震、钻井、岩心和薄片资料分析了该油藏的储层展布格架、油藏构造及演化、油藏类型和控制因素等。在钻井剖面对比图上依据密度和中子测井,将白云岩储层可划分为4个小层。第1、2小层由于位于圈闭构造的较高部位因而通常含油。第3、4小层可能由于在某处与第1、2小层连通,虽然也具低幅度构造和更大的厚度及孔隙度,但多为水层;又因其容易侧向尖灭,故有可能形成地层圈闭。三维地震解释和正演模型均表明,当第1、2小层较厚时,常对应于强振幅和高频反射;当第3、4小层较厚且4个小层并存时会在原储层反射位置下方多出一个波峰同相轴,而且第3、4小层的尖灭通常伴随着该同相轴的终止。这一点有助于寻找与第3、4小层上倾尖灭有关的圈闭。Midale油藏的空间分布受局部低幅度构造和储层小层发育状况的双重控制。油藏驱动机制可能为边水和底水两种类型的结合。根据地震剖面上的地层关系和由三维地震资料所做的古构造演化图来看,油藏低幅度构造的形成与后期地层在前寒武基岩古隆起上的披覆及该隆起在后期多次不整合发生期间的重新活动有关。圈闭雏形形成于早志留到中泥盆世,最终定型于晚白垩世。区域构造演化和油气运移研究表明,有利的油气聚集带位于某些靠近油源区的古鼻隆的东北翼。  相似文献   

A continuum representation of fracture networks. Part II: application to the Äspö Hard Rock laboratory     

Urban Svensson   《Journal of Hydrology》2001,250(1-4):187-205

A method to represent fracture networks in a continuum model is evaluated by an application to the Äspö Hard Rock Laboratory (HRL). The basic approach of the method is to first generate a fracture network, based on data from field measurements and then represent the network as grid cell conductivities, using a staggered grid arrangement. It is argued that the resulting conductivity fields capture the correlation and anisotropy structures, as well as the mean conductivity, of the rock in a realistic way. The main objective is to evaluate if the suggested method can be used in an application to a real site. The objective is formulated in three questions: ‘Can the method utilize available field data?’, ‘Can the generated fields be calibrated and conditioned?’ and ‘Are realistic distributions of pressure, flow and density obtained?’. From the application to the Äspö HRL, it is concluded that the hydraulic conductivity fields, generated by the suggested method, can utilize field data and be calibrated. It is also demonstrated that realistic distributions of pressure, flow and density can be simulated.  相似文献   

Photogrammetric Digitising Systems     

F. Urban 《The Photogrammetric Record》1981,10(58):510-510

  相似文献   

A constitutive model for rock accounting for viscosity and yield stress degradation     

Pawel A. Nawrocki  Zenon Mrz 《Computers and Geotechnics》1999,25(4):80-280

A viscoplastic constitutive model of rock is proposed for which both yield stress and viscosity undergo variation during the deformation process. The model is initially formulated for a uniaxial stress state; its extension for a general stress state is also provided. Model parameters are determined from compression tests at different values of strain rate, and its application to simulate results of such tests is given. The examples of stress redistribution in a coal seam due to progressing longwall exploitation are presented by applying the developed degradation model. The model provides good simulation of material response in both stable and post-critical stages.  相似文献   

Erwiderung zur Diskussion Pavillon     

H. Urban 《Mineralium Deposita》1969,4(4):412-414

Ohne Zusammenfassung  相似文献   

Note on dispersion in an ocean surface Ekman layer due to variable wind forcing     

Dr. Lars Rahm  Dr. Urban Svensson 《Ocean Dynamics》1993,45(1):43-54

  相似文献   

The sensitivity of some high-latitude boreal forests to climatic parameters   总被引：1，自引：0，他引：1  

Gordon B. Bonan  Herman H. Shugart  Dean L. Urban 《Climatic change》1990,16(1):9-29

A gap model of environmental processes and vegetation patterns in boreal forests was used to examine the sensitivity of permafrost and permafrostfree forests in interior Alaska to air temperature and precipitation changes. These analyses indicated that in the uplands of interior Alaska, the effect of climatic warming on the ecology of boreal forests may not be so much a direct response to increased air temperature as it may be a response to the increased potential evapotranspiration demands that will accompany climatic warmings. On poorlydrained north slopes with permafrost, the drier forest floor reduced the flux of heat into the soil profile. This was offset by increased fire severity, which by removing greater amounts of the forest floor increased the depth of soil thawing and converted the cold black spruce forests to warmer mixed hardwood-spruce forests. On well-drained south slopes, the increased potential water loss reduced available soil moisture, converting these mesic sites to dry aspen forests, or if too dry to steppe-like vegetation. Increases in precipitation offset the effects of increased potential evapotranspiration demands and mitigated these forest changes.  相似文献   

Chemical and geochemical studies of Lake Biel   总被引：1，自引：0，他引：1  

Urs P. Nyffeler  Paul W. Schindler  Urban E. Wirz  Dieter M. Imboden 《Aquatic Sciences - Research Across Boundaries》1983,45(1):45-61

The mixing and transport processes in Lake Biel have been studied using the heat and excess Rn-222 as natural tracers. The mixing parameters were established in terms of coefficients of eddy diffusion in a two-dimensional box model. To account for observed transient Rn-222 distribution, transport by advection had to be included in the model calculations. Part I: Peter W. Santschi and Paul W. Schindler: A mass balance for Lake Biel and its implications for the rates of erosion of the drainage area. Schweiz. Z. Hydrol.39, 182–200 (1977).  相似文献