低渗透油藏CO2驱油开发方式与应用     

陈祖华 《现代地质》2015,29(4):950-957

CO₂驱是一种能大幅度提高原油采收率的三次采油技术,国内该项技术的研究和应用起步较晚,多以先导试验为主。苏北盆地溱潼凹陷经过10余年的探索,已经在5个低渗油田开展了CO₂驱先导试验和推广应用,针对这5个油藏利用一维细管模拟和油藏数值模拟方法开展了注气时机、段塞尺寸和注气部位的研究,并应用典型实例进行了分析,认为先期注入提高混相压力,可更有效地缩短两相区过渡带,增加油相中溶解的CO₂含量,降低油相粘度和油气界面张力,进而提高混相程度,更有利于驱油;采用大尺寸段塞可加大CO₂波及区域,较好地保持地层能量,从而提高油井见效率,增强驱替效果;高部位注气可有效地抑制重力超覆,减少CO₂气体过早地产出和突破的机会。就苏北盆地低渗油藏而言,采用先期注入、大尺寸段塞和高部位注气不失为一种成熟有效的提高采收率方法。  相似文献   

特超稠油油藏水平井蒸汽驱油物理模拟实验     

郑贺梅  刘鹏程  郑舰 《现代地质》2015,29(6):1467-1474

以胜利油田A区块特超稠油油藏为目标区块,自主研发了高温高压二维比例物理模型,研究了不同开发阶段水平井蒸汽驱油机理,开展了油藏压力、井底干 度、注汽强度对水平井蒸汽驱的效果影响的研究。物模实验结果显示,蒸汽驱整个过程分为三个阶段：存水回采期、汽驱受效期、蒸汽突破期。存水回采期蒸汽腔向水平方向扩展,以水平驱替方式为主 ;汽驱受效期蒸汽腔向垂向和水平方向扩展,以水平驱替方式为主,纵向泄油为辅;后期蒸汽突破,蒸汽腔继续向上方扩展,以纵向泄油为主,实现油层整体动用。5 MPa时转蒸汽驱的采出程度高于7 MPa时转蒸汽驱的采出程度;蒸汽驱的井底蒸汽干度应不低于0.4,蒸汽干度越高,水平井蒸汽驱的开发效果越好;注汽强度为1.9 t/(d·ha·m)时温度场最为发育。同时,在高压下提高干度可实现水 平井蒸汽驱的有效开发。以上的实验结果较好地指导了胜利油田A区块特超稠油油藏水平井蒸汽驱开发,取得了明显的开发效果,该研究对于类似稠油和超稠油油藏水平井蒸汽驱开发具有重要的指导意义 。  相似文献   

不同时间尺度、季节的气温数据空间平稳特征及其对插值结果的影响     

郭春霞  诸云强  孙伟 《地理研究》2015,34(9):1675-1684

不同时间尺度、季节的气温数据表现出不同的空间平稳特征。为探讨分析空间平稳性对气温插值的影响规律,采用趋势线法对气温数据进行空间平稳性探索,并对比分析不同空间平稳性条件下,普通线性回归、普通克里格、回归克里格的气温插值精度及插值结果的空间分布特点。结果显示：冬季日均、月均气温与年均气温呈现空间非平稳,插值精度随时间序列的增长而提高,随着气温数据逐渐趋于稳定,精度提高的幅度逐渐下降;夏季日均、月均气温呈现空间平稳,随时间序列的增长,插值精度的提高并不显著;夏季日均气温各插值方法的插值精度普遍高于冬季日均气温。与普通克里格相比,回归克里格能有效提高空间非平稳数据的插值精度。时间序列的增长削弱了不同插值算法之间的插值精度差异和插值结果空间分布差异。  相似文献   

沈阳市2017年地下水枯水期与丰水期水化学类型对比研究     

由钰婷 《地下水》2019,(1):47-50

沈阳市属于温带季风性气候,夏季多雨冬季干旱,枯水期和丰水期区别明显,对于地下水水化学类型有较大影响。本文使用阿列金分类法进行评价,得到CⅢCa全年都为绝对优势,丰水期占比较枯水期更大;枯水期与丰水期水化学类型差别较小,说明丰水期降水对于各县区的水化学类型影响较小,反而枯水期地下径流路径更长,溶出更加充分;从各县区看,康平县、法库县丰水期和枯水期水化学类型基本比重没有大的变化,新民市、沈北新区、于洪区、东陵区、辽中区、苏家屯区水化学类型均有一定差异;枯水期和丰水期各县区水化学类型都以Ⅲ型水为主。  相似文献   

Sedimentary control on the formation of a multi-superimposed gas system in the development of key layers in the sequence framework     

《Marine and Petroleum Geology》2017

Based on core observations, well logs and test results of siderite-bearing mudstone from the Benxi Formation to the Member 2 of the Shanxi Formations in the Linxing block, northeastern Ordos Basin, a logging identification model for siderite-bearing mudstone (key layer) was established. The porosity characteristics and sealing property were quantitatively evaluated by logging data. Sedimentary control on the formation of multi-superimposed gas-bearing system in the development of key layers in the sequence framework was also discussed. The results showed that the siderite-bearing mudstone has obvious logging response characteristics, e.g., high photoelectric absorption cross-section index (PE), high density (DEN), high amplitude natural gamma ray (GR), low acoustic (AC), low resistivity (M2RX) and low neutron porosity (CNCF). The quantitatively evaluated results of the porosity characteristics and sealing property for the key layer showed that the key layer has the characteristics of low porosity (with an average of 1.20 percent), low permeability (with an average of 2.29 × 10⁻⁸μm²), and high breakthrough pressure (with an average of 12.32 MPa) in the study area. This layer acts as an impermeable gas barrier in a multi-superimposed gas system. The results also indicated that the material composition of the multi-superimposed gas-bearing system can be established by the sequence stratigraphic framework. The sedimentary evolution results in a cyclic rhythm of material composition vertically. The spatial distribution of the corresponding transgressive event layer near the maximum flooding surface (MFS) in the sequence framework restricts the spatial distribution of the key layer with high breakthrough pressure and low porosity, which constitutes the gas-bearing system boundary. The siderite-bearing mudstone formed near the MFS in the second-order sequence and constitutes a stable comparison of the first-order gas-bearing system boundary, which has a wide range of regional distribution and stable thickness. The siderite-bearing mudstone formed near the MFS in the third-order sequence is often incompletely preserved due to the late (underwater) diversion channel erosion and cutting. This layer forms the coal-bearing reservoirs, which we termed as a second-order gas-bearing system in adjacent third-order sequences to form a uniform gas-bearing system.  相似文献   

广海湾康氏小公鱼的产卵期及其鱼卵数量变动          下载免费PDF全文

田丰歌  郑琰晶  肖瑜璋  方宏达 《应用海洋学学报》2017,36(3):395-402

根据2013~2015年在台山市广海湾海域(21°52'~21°56'N,112°46'~112°53'E)进行逐月调查的资料,分析了该水域康氏小公鱼(Stolephorus commersonii)鱼卵在一年中出现的时间、数量变动特征以及期间的海水温盐特征,并讨论了康氏小公鱼产卵期与水温变化的关系.结果表明,广海湾康氏小公鱼的产卵期开始于每年3月左右,结束时间在各年份不同,一般在9~11月之间.康氏小公鱼鱼卵在一年中分多个批次出现,一般可出现2~4个批次,其中第一批次为产卵盛期,数量高峰大约出现在4月前后.鱼卵出现期间平均水温的范围为19.8~31.3℃,平均盐度范围为7.66~33.65,从出现频次上看,其所在环境以高温低盐为主.康氏小公鱼产卵所需的最低温度在20℃左右,在产卵期开始前,海水温度何时升至此温度,决定了一年中康氏小公鱼鱼卵最早出现的时间.对比不同纬度的海域,康氏小公鱼产卵期的开始时间随纬度的升高而向后推迟.  相似文献   

1991～2013年发生在西沙永兴岛的台风风暴潮统计特征分析          下载免费PDF全文

梁海萍  梁海燕  陈海南  陈道严 《应用海洋学学报》2017,36(2):243-248

利用1991～2013年西沙海洋站实测的潮位、气压、风资料,统计分析发生在西沙永兴岛的台风风暴潮特征.统计结果为以后的台风风暴潮增水预报工作提供一定借鉴.统计分析发现：发生在永兴岛的台风风暴潮过程年最大增水值基本在34cm处上下波动,最高预警级别仅为蓝色;最大增水有明显的年际变化特征,预计接下来10a左右发生在永兴岛的台风风暴增水值大体逐年递减;最大增水若与极大天文潮相叠加,在永兴岛可能出现灾害性高潮位;年最大增水有明显的季节特征,在夏季最强,其次为秋季,冬季和春季最弱;台风中心经过时由负压引起的增水较为明显,单峰型、双峰型和振荡型的增水曲线形态均有出现;影响西沙永兴岛的热带气旋的年最大风速年际与季节性变化是导致永兴岛台风风暴潮特征的主要成因之一.  相似文献   

流域水文年及丰枯水期划分方法          下载免费PDF全文

刘赛艳  解阳阳  黄强  蒋晓辉  李向阳 《水文》2017,37(5):49-53

研究流域水文年及丰、枯水期划分方法,为水文水利计算提供科学依据。通过分析流域径流变化特点,提出径流累计距平法。将该方法用于黑河上游流域,结果表明:该方法为黑河上游流域确定了合理的水文年及丰、枯水期;在不同水文年起讫日下,黑河上游流域年径流时间序列的统计特性和典型年的径流年内分配特征发生显著变化。因此,径流累计距平法可用于划分流域水文年及丰、枯水期,统一水文年划分方式对水文水利计算十分必要。  相似文献   

蒙古野驴(Equus hemionus)昼间行为时间分配初探   总被引：1，自引：0，他引：1  

刘伟  杨维康  黄怡  徐文轩  林杰  夏参军  徐峰  David Blank 《干旱区地理》2012,35(4):607-614

于2007 年和2010 年采用焦点动物取样法研究了新疆卡拉麦里山有蹄类野生动物保护区蒙古野驴昼间行为时间分配和活动节律,共采集行为数据460 h,观察蒙古野驴2 760 头次,将蒙古野驴昼间行为分为采食、移动、警戒、休息和“其他”5 类。采用卡方检验分析不同季节各种行为时间分配,结果表明：季节因素对蒙古野驴行为时间分配存在极显著影响（χ2=79.06,df=12,P<0.01）。采用ANOVA分析同季节不同行为间差异,结果表明,春季：移动、警戒、“其他”两两间无显著差异（[WTBX]P＞0.05）,其余两两间差异显著（P＜0.05）;夏季：仅移动与“其他”间无显著差异（P＞0.05）;秋冬季：仅警戒与“其他”间无显著差异（P＞0.05）。对蒙古野驴昼间活动节律研究结果表明,蒙古野驴采食时间比例在春季各时段均较高（＞45%）,仅中午（14:00～15:00）有1个低谷（27.62%）,夏秋季则为晨昏采食模式,冬季采食峰值（87.85%）在中午时段（13:00～14:00）。休息和采食高峰在各季节交叉出现,呈现此消彼长的趋势。各季节移动主要发生在晨昏时段。蒙古野驴以特定的行为时间分配模式和活动节律适应环境条件季节性变化,如气候条件、食物资源、人为干扰、生理期、昼间长度、捕食风险等。  相似文献   

Topographic predictors of susceptibility to alluvial fan flooding,Southern Apennines   总被引：2，自引：0，他引：2  

N. Santangelo  J. Daunis‐i‐Estadella  G. Di Crescenzo  V. Di Donato  P. I. Faillace  J. A. Martín‐Fernández  P. Romano  A. Santo  V. Scorpio 《地球表面变化过程与地形》2012,37(8):803-817

The flooding susceptibility of alluvial fans in the Southern Apennines has long been neglected. To partly address this oversight, we focus on the region of Campania which contains highly urbanized piedmont areas particularly vulnerable to flooding. Our findings are based on stratigraphic analysis of the fans and morphometric analysis of the basin‐fan systems. Using geomorphological analysis we recognized active alluvial fans while stratigraphic analysis together with statistical analysis of the morphometric variables was used to classify the fans in terms of the transport process involved. The results indicate that in the geological context examined, the best discrimination between debris flow (Df) and water flood (Wf) processes is achieved by means of two related variables, one for the basin (feeder channel inclination, Cg) and one for the fan (fan length, Fl). The probability that an unclassified fan belongs to group Wf is computed by applying a logistic function in which a P value exceeding 0.5 indicates that a basin/fan system belongs to group Wf. This important result led to the classification of the entire basin/fan system data. As regards process intensity, debris flow‐dominated fans are susceptible to the occurrence of flows with high viscosity and hence subject to more severe events than water flood‐dominated fans. Bearing this in mind, the data gathered in this study allow us to detect where alluvial fan flooding might occur and give information on the different degrees of susceptibility at a regional scale. Regrettably, urban development in recent decades has failed to take the presence of such alluvial fans into account due to the long recurrence time (50–100 years) between floods. This paper outlines the distribution of such susceptibility scenarios throughout the region, thereby constituting an initial step to implementing alluvial fan flooding control and mitigation. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献