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1.
随钻地层压力测试可在钻井的过程中实时提供地层压力信息,达到提高钻井效率,优化钻井工艺的目的。但由于钻井过程中泥浆滤液侵入地层,造成近井地带地层出现增压效应,增压效应导致随钻地层压力测试结果失真。因此,针对随钻地层压力测试过程中存在的增压效应,分析增压效应产生的主要原因和形成机理,建立了泥饼形成条件下增压压力的理论模型,采用该模型模拟了不同地层、地层流体、泥饼和井筒环境下的增压响应规律,揭示了随钻地层压力测试增压效应的响应机理。研究表明,地层渗透率、泥饼渗透率和过平衡压力的大小是影响增压效应的主要因素,在地层渗透率较低、泥饼渗透率较高情况下增压效应明显增大。  相似文献   

2.
本文对钻穿效应和屏蔽效应的实质进行了进一步的探讨,并从哈特里一福克法的计算结果给出了一些定量的依据。  相似文献   

3.
本文系统研究了周期表中65种元素的有效核电荷,利用原子(或离子)的半径及电子的屏蔽效应和钻穿效应,讨论了惰性价电子效应产生的普遍性;并根据周期表中元素的性质,揭示了这一效应所表现出的规律性。  相似文献   

4.
本文在简述“电子云钻穿效应”的产生历史和介绍其主要内容之后,从量子力学观点对它的根据及应用作了分析与讨论,认为:“电子云钻穿效应”的量子力学基础不牢靠;把它说成是“径向分布能量效应”的论据不能令人信服;用以解释能级交错等问题也是值得进一步探讨的.  相似文献   

5.
综合原子半径、钻穿效应、镧系收缩等理论 ,以氮族元素为例 ,从原子结构角度 ,分析产生“惰性电子对效应”的原因  相似文献   

6.
针对高速背板的过孔Stub效应设计了几种优化方法:对单过孔,采用高速布线中换层尽量远或采用背钻工艺以减少Stub效应对信号的影响;对差分过孔,在差分过孔旁边打一对地过孔和对差分残段进行背钻处理以减少Stub效应对信号的影响.利用HFSS建立三维模型以验证方法的有效性,仿真结果表明,本文方法消除了过孔Stub效应、改善了信道的信号质量.  相似文献   

7.
本文结合SPZ型深孔喷射钻具的研制与实验,着重分析了喷射效应在钻削过程中的应用,建立了流体系统的数学关系式,为深孔喷射钻的设计提供了必要的理论依据。  相似文献   

8.
从经济和工艺技术方面考虑,在硬岩地区进行地铁隧道的开挖,最适合的方法就是钻爆施工方法。但是钻爆法施工产生的爆破地震效应会对地表建筑物产生较大的危害,尤其是紧贴既有建筑物的浅埋中等断面隧道。控制爆破的地震效应,就要对爆破方法进行地震效应的研究。文章采用显示动力学分析有限元软件ANSYS/LS-DYNA3D对传统乳化炸药爆破方式和引进的金属膨胀剂爆破方式进行数值模拟,利用计算出爆破振动速度的时程和爆破破碎围岩的效果进行对比分析,并评价2种爆破方式的优缺点。  相似文献   

9.
随钻D-T中子孔隙度测井低灵敏度和岩性影响校正方法研究   总被引:1,自引:1,他引:0  
为了提高随钻氘-氚(D-T)中子孔隙度测井的测量精度,通过研究其在多种岩性、孔隙度地层中的响应,对比与化学源的响应差异,分析所测孔隙度灵敏度及精度偏低的原因,并提出对应的校正方法。结果表明:由于D-T源能量较化学源高,地层密度对含氢指数测量影响增强,使得随钻D-T中子孔隙度测井地层孔隙度灵敏度偏低,且受到泥页岩效应的影响较大;密度校正后,地层孔隙度灵敏度显著提高,且受到岩性的影响降低,尤其是泥页岩效应几乎被完全消除。因此,通过对随钻D-T中子孔隙度测井结果的校正,测量灵敏度和精度都得到大幅提高,可以较好地替代化学源测量地层中子孔隙度。  相似文献   

10.
结合井眼环境下随钻测井电磁场数值模拟计算的研究结果,分析了中浅电阻率和相位移深中浅电阻率这两大类随钻电阻率曲线异常变化的主要特征和产生的原因。并以中海油渤中地区哈里伯顿公司EWR–Phase 4随钻测井仪器所测量的这两类电阻率曲线为例进行详细阐述。选取了3口典型井的随钻幅度衰减和相位移电阻率曲线,通过对地层岩性、渗透性、泥浆侵入,机械钻速、井眼环境等几个因素的分析,特别是对极浅、浅、中和深电阻率曲线的变化范围和变化趋势等曲线特征进行了分析。研究认为,电阻率曲线异常主要表现为佐罗效应、"窗帘花边"效应和极化角突变等几种主要类型,而引起这种异常变化的原因既有井眼或地层倾斜的影响,也有薄互层、非均质性、螺纹井眼以及钻铤侧向震动等诸多方面的影响。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

14.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

15.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

16.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

17.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

18.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

19.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

20.
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