气藏压裂水平井产能预测新方法

根据流体力学理论和动量定理，结合气体的性质和实际气体的状态方程，建立了气藏压裂水平井地层渗流和水平井筒管流耦合的计算模型，并给出了模型的求解方法。运用该模型对长庆油田低渗气藏进行了实际计算，同时分析了井筒半径、水平段长度、裂缝条数以及管壁粗糙度等参数对井筒压力损失和压裂水平气井产能的影响。计算结果表明，水平井筒内的压力损失对压裂水平井的生产动态有一定的影响；水平井内每条压裂缝的产量并不相等，端部裂缝的产气量高于中部裂缝的产气量；水平井筒内的压力呈不均匀分布，从指端到根端压力逐渐降低。     

低渗气藏压裂水平井渗流与井筒管流耦合模型

目前国内外压裂水平井已成为开发低渗透油气藏的重要手段,正确预测压裂水平井的产能对水平井的开发方案设计、地层及裂缝参数等敏感性分析具有重要的指导意义。应用复位势理论和势的叠加原理,考虑气体在地层中渗流和井筒内管流的耦合,根据流体力学理论和动量定理,结合气体的性质和实际气体的状态方程,建立低渗透气藏压裂水平井地层渗流与水平井筒管流耦合的渗流模型及其求解方法。结合长庆低渗气藏实际进行对比计算,结果表明：（1）水平井筒内的压力损失对压裂水平气井的生产动态有一定的影响;（2）井筒内的压力呈不均匀分布;（3）每条裂缝的产量并不相等。在此基础上还分析了井筒半径、水平段长度、裂缝条数以及管壁粗糙度等参数对井筒压力损失和压裂水平气井产能的影响,得出一些有用的结论。     

水平井压裂裂缝起裂及裂缝延伸规律研究

水平井压裂可以有效提高低渗透油气藏水平井的采油速度和最终采收率,裂缝起裂和裂缝延伸规律是水平井压裂的关键问题之一.建立了水平井压裂裂缝起裂压力计算模型,通过分析求解模型可以得出:井筒方位角不同,最小水平主应力和垂直主应力对裂缝的起裂压力影响规律不同,在井筒方位角为0°时最不容易起裂,而在井筒方位角为90°时最容易起裂;对比分析了现有裂缝延伸模型,得出全三维裂缝延伸模型适合水平井压裂裂缝延伸模拟;分析了产层和盖层的应力差对裂缝缝高的影响,计算结果表明,当隔层与产层的应力差大于5MPa时,裂缝被限制在产层内.     

裂缝参数对压裂水平井入流动态的影响

基于拟稳态等效井径模型、裂缝内变质量线性流模型、水平井筒变质量流模型和完井表皮系数模型,根据势叠加与连续性原理,建立压裂水平井裂缝变质量流与油藏渗流的耦合模型,分析裂缝半长、裂缝宽度、裂缝渗透率对水平井筒和裂缝的入流速度及压力降分布、压裂水平井产能的影响.结果表明:随裂缝半长、裂缝宽度、裂缝渗透率增大,水平井段入流速度、产量减小,压裂水平井和裂缝产量增大;裂缝宽度越宽、裂缝渗透率越大,裂缝入流速度越大,裂缝内压降损失越小;越靠近外侧的裂缝入流速度越快,裂缝内压力损失越大.     

分段压裂水平井的温度分布预测模型

温度预测模型是实现基于分布式温度测试(DTS)解释产出剖面的基础,但定量预测低渗气藏压裂水平井温度剖面仍是一个难题。为此,建立了一套考虑多种微热效应的低渗气藏压裂水平井耦合温度预测模型,模拟了一口低渗气藏压裂水平井的温度剖面,分析了温度剖面特征,并采用正交试验分析法评价了压裂水平井温度剖面对不同因素的敏感性。研究结果表明：①压裂水平井温度剖面呈现出不规则的“锯齿状”,任一“锯齿”都对应着一条有效人工裂缝;②各级裂缝处的井筒温降基本上与裂缝半长呈正相关关系;③从趾端到跟端,各级裂缝位置处的井筒温降与裂缝半长的比值(△T/xf) 依次递减;④压裂水平井温度剖面对各因素的敏感性依次为：裂缝半长>产量>地层渗透率>井筒半径>地层孔隙度>裂缝导流能力>水平倾角。该研究成果为实现基于DTS解释压裂水平井产出剖面提供了模型基础和理论支撑,对于压裂水平井改造效果评价和出水位置定量诊断具有重要意义。     

分段压裂水平气井产能数值模型建立

随着水平井分段压裂技术在致密气藏开发中广泛应用,压裂后产能的预测对开发此类气藏具有重要意义。应用复位势理论和势叠加原理等基本渗流理论,结合水平井压后裂缝形态和单相气体渗流机理,推导出考虑水平井筒内压降损失时的产能预测新模型。模型综合考虑了多条裂缝间的相互干扰和各条裂缝的长度、缝宽、导流能力、缝间距对各条裂缝产量的影响以及水平井筒内压降损失对产能的影响,建立了考虑多因素的水平气井产能数值模型。编制了模拟计算软件。并以长庆油田某致密气藏区块为例进行了裂缝方案优化设计。研究成果对于低渗致密气藏井网部署及开发方案编制具有一定的指导意义。     

裂缝性地层中水平井压裂裂缝起裂新模型

对裂缝性地层中的水平井进行水力压裂时,井筒附近的天然裂缝会对压裂产生影响。现有压裂裂缝起裂压力计算模型所考虑的影响因素各有侧重,且尚未考虑井筒附近天然裂缝产生的诱导应力场对起裂压力造成的影响。本文基于弹性力学及岩石力学理论,综合考虑了井筒周围天然裂缝的诱导应力、压裂液渗滤效应、岩石温度变化、封隔器影响等因素,建立了一个适用于裂缝性地层中的水平井压裂裂缝起裂压力计算模型,且计算简便便于推广。本文根据实例计算分析了天然裂缝影响起裂压力的各个因素,并进行了对比。计算结果表明,一定条件下井筒周围天然裂缝对起裂压力影响明显,采用以前的起裂压力计算模型误差较大。     

低渗气藏水平井不同完井方式产能预测研究

根据气藏内气体的流动模型和水平井筒内流体的流动模型,建立了气藏-水平井筒流体流动的耦合模型,该模型充分考虑了气藏内的各向异性和气体的非达西流动.利用拟压力采用非稳态方法求解气藏水平井的产能模型,预测了裸眼完井、射孔完井和压裂完井的水平井气井产能,分析了影响产能的因素,并将其与直井压裂的产能进行了对比.     

低渗透油藏压裂水平井产能计算新方法

应用复位势理论和势的叠加原理,推导出考虑裂缝与水平段同时生产的油层中渗流模型;应用流体力学理论、质量守恒定理和动量定理,推导出考虑水平井简沿程油层流体流入和裂缝流体流入的井筒内压降计算模型.在此基础上建立了油层中渗流和井筒内管流耦合的产能模型,并给出其求解方法.实例计算结果与实验结果对比表明,进行压裂水平井生产动态分析时,不能忽略水平井筒沿程油层流体流入的影响;水平井筒内的压力降对产量有一定的影响,水平井筒长度存在最优范围;各条裂缝产量不相等,裂缝条数存在最优范围.     

低渗气藏水平井不同完井方式产能预测研究

根据气藏内气体的流动模型和水平井筒内流体的流动模型，建立了气藏-水平井筒流体流动的耦合模型，该模型充分考虑了气藏内的各向异性和气体的非达西流动．利用拟压力采用非稳态方法求解气藏水平井的产能模型，预测了裸眼完井、射孔完井和压裂完井的水平井气井产能，分析了影响产能的因素，并将其与直井压裂的产能进行了对比．     

Markedness and its Interpretation in Language Use

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

Features of Women's language

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.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

低渗透非均质砂岩油藏启动压力梯度研究

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。     

On Tragic Consciousness In The Works By Ernest Hemingway

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.     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to