预防油页岩地层钻进中压差卡钻的措施     

赵宪富  台沐礼  孙德学  张元清  吕洪富 《探矿工程》2008,35(9):21-23

分析了油页岩地层钻进中压差卡钻发生的原因,提出了预防压差卡钻的途径及处理方法,并通过工程实例来强调预防为主的重要性。  相似文献   

GYD-300型全液压动力头工程钻机的研制     

靳益民  高淑芳 《探矿工程》2008,35(12):23-25,34

GYD-300型全液压动力头工程钻机为全液压驱动,动力头反循环式机型。液压系统采用插装阀集成结构,电液复合操作。使用PC控制监测系统,适时检测孔底各相关压力,对不同地层进行范围设置,实现钻进过程中孔底的自动、手动恒压钻进。重点介绍了该钻机的结构特点、实验情况、主要技术参数等。  相似文献   

地幔岩中流体包裹体研究   总被引：5，自引：2，他引：3  

卢焕章 《岩石学报》2008,24(9):1954-1960

地幔岩石中的流体包裹体代表地幔流体的样品。地幔流体包裹体可以存在从地幔来的金刚石,地幔捕虏体和岩浆碳酸岩中。研究这些岩石和矿物中的流体包裹体可以得出其所代表的地幔流体的温度、压力、成分和同位素。我们目前见到的这三类地幔岩石的包裹体主要可在橄榄石、辉石、金刚石、方解石和磷灰石中见到。这些包裹体可以粗略地分为CO2包襄体和硅酸盐熔融体包裹体。又可细分为四类包裹体：（1）富碳酸盐的硅酸盐熔融包裹体。这种包裹体在金刚石、地幔岩捕虏体和岩浆碳酸盐岩中见到,它又可分为结晶质熔融包裹体和玻璃包裹体。（2）CO2包裹体。这种包裹体大多见于地幔捕虏体中,在金刚石和岩浆碳酸岩中也可见到。（3）含硫化物的包裹体。这种包裹体见于地幔捕虏体中,与纯CO2包裹体和含CO2的熔融包裹体共存。（4）高密度的流体包裹体。这种包裹体见于金刚石中,是一种高盐度、高密度的含K、Cl和H2O的流体包裹体,又可分为高卤水包裹体和含卤水的富硅的碳酸盐岩浆包裹体。从对金刚石、地幔捕虏体和岩浆碳酸盐岩中流体包裹体的研究表明,地幔流体存在不均匀性和不混溶性。  相似文献   

1.0GPa和常温至1100 ℃条件下角闪石斜长片麻岩的V_p变化:实验测量与理论计算   总被引：3，自引：0，他引：3  

蒋玺  周文戈  刘丛强  谢鸿森  刘永刚 《岩石学报》2008,24(10)

在1．0GPa、常温至1100℃条件下测量了角闪石斜长片麻岩的纵波速度（Vp）,并统计了不同温度实验产物中各种矿物的体积百分含量。结果显示,1．0GPa下,角闪石斜长片麻岩的Vp首先随温度升高（室温至700℃）缓慢降低约6％,然后（700—850℃）快速降低约6％,再（850～950℃）转而急剧升高15％～25％,最后（T〉950℃）又快速下降。实验产物分析表明在高温高压下α-石英-β石英相变和岩石部分熔融是岩石Vp异常变化的主要因素。由取样产物的矿物含量和弹性参数,计算了各温度条件下岩石的Vp得出与实验测量相同的波速-温度变化趋势,即Vp随温度升高先缓慢降低,接着快速降低后又急剧升高,最后又快速减小。实验测量和理论计算对比研究表明,通过高温高压下岩石中的物相变化观测结果进行岩石波速的计算,是检验岩石弹性波速测量结果和研究地球内部地震波结构的一种有效方法。  相似文献   

影响低渗透油藏低速非线性渗流的实验研究     

王正波  岳湘安  韩冬  王金峰 《矿物学报》2008,28(1):48-54

以膨胀性的粘土为主要研究对象,通过粘土浆体的流变性实验和填砂管渗流实验,并使用一种新研制的微流量测量工具,研究了低渗岩心在较低流速下的渗流特性;利用微尺度流动理论,Einstein粘度定律等进行了理论分析,对引起低渗透油藏低速非线性渗流的影响因素进行了初步的探索.结论认为,粘土的膨胀性以及其水化后形成浆体的流变性是引起低速非线性渗流的主要因素之一.  相似文献   

岩石破坏前后曲线分类及脆-延转换围压研究——蚀变岩常规三轴压缩试验Ⅰ   总被引：2，自引：0，他引：2  

杨根兰  黄润秋  蔡国军  付小敏  林锋  徐德敏 《岩土力学》2008,29(10):2759-2763

蚀变岩是工程中少见的软弱岩类,在西南某重大水电工程中,蚀变岩处于工程的重要部位,为保证工程的长期稳定性,对蚀变岩力学特性进行了深入全面的试验研究.通过对孔隙度不同的饱水蚀变岩进行系统的常规三轴压缩试验和总结分析,提出了蚀变岩三轴压缩下破坏前应力.应变曲线可分为3大类,破坏后应力-应变曲线亦可分为3大类的形态模式.并得出结论:蚀变岩的破坏类型受围压与孔隙度的共同影响,在给定的12 MPa围压下蚀变岩以脆性破坏为主,只有孔隙度大于16%且围压大于4 MPa时才有可能进入脆-延转换状态,且脆-延转换围压随孔隙度增加而降低,临界状态应力比随孔隙度增大而增加.  相似文献   

Numerical Experiment on Two-Dimensional Line Thermal     

J.H.W.LEE  G.Q.CHEN 《中国海洋工程》2002,16(4):453-467

The time evolution of a two-dimensional line thermal-a turbulent flow produced by an initial element with signifi-cant buoyancy released in a large water body, is numerically studied with the two-equation k - e model for turbulence closure. The numerical results show that the thermal is characterized by a vortex pair flow and a kidney shaped concentra-tion structure with double peak maxima; the computed flow details and scalar mixing characteristics can be described by self-similar relations beyond a dimensionless time around 10. There are two regions in the flow field of a line thermal: a mixing region where the concentration of tracer fluid is high and the flow is turbulent and rotational with a pair of vortex eyes, and an ambient region where the concentration is zero and the flow is potential and well-described by a model of doublet with strength very close to those given by early experimental and analytical studies. The added virtual mass coeffi-cient of the thermal motion is found to be approximat  相似文献   

Effect of Cyclic Loading Frequency on Undrained Behaviors of Undisturbed Marine Clay   总被引：2，自引：0，他引：2  

陈云敏  姬美秀黄博 《中国海洋工程》2004,18(4):643-651

Based on a series of cyclic triaxial tests, the effect of cyclic frequency on the undrained behaviors of undisturbed marine clay is investigated. For a given dynamic stress ratio, the accumulated pore water pressure and dynamic strain increase with the number of cycles. There exists a threshold value for beth the accumulated pore water pressure and dynamic strain, below which the effect of cyclic frequency is very small, but above which the accumulated pore water pressure and dynamic strain increase intensely with the decrease of cyclic frequency for a given number of cycles. The dynamic strength increases with the increase of cyclic frequency, whereas the effect of cyclic frequency on it gradually diminishes to zero when the number of cycles is large enough, and the dynamic strengths at different frequencies tend to the same limiting minimum dynamic strength. The test results demonstrate that the reasons for the frequency effect on the undrained soil behaviors are beth the creep effect induced by the loading rate and the decrease of sample effective confining pressure caused by the accumulated pore water pressure.  相似文献   

一种计算台风风场的方法     

陈孔沫 《热带海洋学报》1994,(2)

揭示Ｒａｎｋｉｎｅ涡风场模式和Ｊｅｌｅｓｎｉａｎｓｋｉ风场模式之间的联系，并设计了一种台风风场分布模式，它的风速分布曲线落在Ｊｅｌｅｓｎｉａｎｓｋｉ和Ｒａｎｋｉｎｅ涡两个风场模式的风速分布曲线之间，具有一个既优于Ｊｅｌｅｓｎｉａｎｓｋｉ又优于Ｒａｎｋｉｎｅ涡的风速衰减速率，因此它同时克服了Ｒａｎｋｉｎｅ涡模式计算风速偏小和Ｊｅｌｅｓｎｉａｎｓｋｉ模式计算风速偏大的缺点，以一种比较合理的变化趋势向远方衰减，成为一个比较切合实际的台风风场分布模式。同时，文中提出的移行台风风场计算方法对宫崎正卫、上野武夫和Ｊｅｌｅｓｎｉａｎｓｋｉ模式都有一定的改进。  相似文献   

Geophysical evidence of mud diapirism on the Mediterranean Ridge accretionary complex   总被引：2，自引：0，他引：2  

A. Camerlenghi  M. B. Cita  B. Della Vedova  N. Fusi  L. Mirabile  G. Pellis 《Marine Geophysical Researches》1995,17(2):115-141

Mud volcanoes, mud cones, and mud ridges have been identified on the inner portion of the crestal area, and possibly on the inner escarpment, of the Mediterranean Ridge accretionary complex. Four areas containing one or more mud diapirs have been investigated through bathymetric profiling, single channel seismic reflection profiling, heat flow measurements, and coring. A sequence of events is identified in the evolution of the mud diapirs: initially the expulsion on the seafloor of gasrich mud produces a seafloor depression outlined in the seismic record by downward dip of the host sediment reflectors towards the mud conduit; subsequent eruptions of fluid mud may create a flat topped mud volcano with step-like profile; finally, the intrusion of viscous mud produces a mud cone.The origin of the diapirs is deep within the Mediterranean Ridge. Although a minimum depth of about 400 m below the seafloor has been computed from the hydrostatic balance between the diapiric sediments and the host sediments, a maximum depth, suggested by geometric considerations, ranges between 5.3 and 7 km. The presence of thermogenic gas in the diapiric sediments suggests a better constrained origin depth of at least 2.2 km.The heat flow measured within the Olimpi mud diapir field and along a transect orthogonal to the diapiric field is low, ranging between 16 ± 5 and 41 ± 6 mW m^–2. Due to the presence of gas, the thermal conductivity of the diapiric sediments is lower than that of the host hemipelagic oozes (0.6–0.9 and 1.0–1.15 W m^–1 K^–1 respectively).We consider the distribution of mud diapirs to be controlled by the presence of tectonic features such as reverse faults or thrusts (inner escarpment) that develop where the thickness of the Late Miocene evaporites appears to be minimum. An upward migration through time of the position of the décollement within the stratigraphic column from the Upper Oligocene (diapiric sediments) to the Upper Miocene (present position) is identified.  相似文献