提取断层位移突变信息的一种方法与实践

本文提出了一种适合于跨断层形变测量数据处理的相对分析平差原理,并应用突变论方法分析了相对位移突变及其稳定性问题,实例验证了方法的正确性。     

Research on thermal structure and thermal stress of the crust in Bohai Sea and its surroundings

In this paper, the three-dimensional thermal structure and the two-dimensional thermal stress caused by the horizontal inhomogeneity of the thermal structure in the crust of the Bohai Sea and its surroundings were analyzed using the geothermal and the crust structural data by means of the finite element method. As resulted, the horizontal distribution of the temperature in the upper crust is obviously different from that in the lower crust in most part of the region. But the horizontal distribution of the heat flow is constant in the crust. There is a belt where the thermal structure of the crust is intensely changed around Tangshan. There are some different characteristics of the thermal stress of the crust around Tangshan, in the North-China plain, in the Bohai Sea gulf, and in the middle part of the Bohai Sea. Utilizing those results, the distribution features of the seismic activity in the region were explained in this paper. The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,14, 29–35, 1992. This project is supported by the Chinese Joint Seismological Science Foundation.     

Calcium Isotopic Fractionation during Ion‐Exchange Column Chemistry and Thermal Ionisation Mass Spectrometry (TIMS) Determination

Significant isotopic fractionation can occur during column chemistry and determination by mass spectrometry. Improper correction may produce uncertainties in the isotopic composition of geological samples. We investigated calcium isotopic fractionation during these two processes and set up a model to check data quality. The δ^44/40Ca_915a value of IAPSO seawater in different Ca cuts (e.g., 0–20, 20–40, 40–60, 60–80 and 80–100%) on column chemistry ranged from ~ 4‰ to 0‰. The more Ca was eluted, the lower the δ^44/40Ca_915a value of the elution was found. The isotopic fractionation of calcium on the column appeared to follow the exponential law. However, TIMS instrumental fractionation during Ca runs did not always follow the exponential law due to mixing effects from sample reservoirs on the filament. Our results show that errors could be caused if the instrumental fractionation deviates from the exponential law, especially when the fractionation degree is large. To improve the measurement uncertainty, a model is proposed to check the behaviour and degree of instrumental fractionation, which will provide a quick and reasonable verdict on the data quality of TIMS runs.     

Effect of fibre inclusion on dynamic properties of clay

One of the causes of heavy damage due to earthquake motions is the role of soft clay in amplifying bedrock ground motions. Improving the soil conditions using polypropylene fibres at a site in order to mitigate earthquake damage could be one of the methods to modify site conditions. In this study, the optimum fibre contents were obtained for mixtures of clay with two different types of fibre. Then the dynamic properties of polypropylene fibre reinforced clay with different fibre contents were determined using resonant column testing. The study showed that the inclusion of fibre at optimum fibre content can improve the dynamic properties of clay at the low shear strains used. Test results indicated that both the shear modulus and damping increased. Hence, the inclusion of fibre in clay can provide a double benefit for the dynamic response of a site by increasing the stiffness of the site and reducing its amplitude of vibration.     

Dynamics of fluid and heat flow in a CO2-based injection-production geothermal system

CO2 is now considered as a novel heat transmission fluid to extract geothermal energy. It can be used for both energy exploitation and CO2 geological sequestration. Here, a 3-D, “two-spot” pattern well model is developed to analyze the mechanism of CO2-water displacement and heat extraction. To obtain a deeper understanding of CO2-geothermal system under some more realistic conditions, heterogeneity of reservoir’s hydrological properties is taken into account. Due to the fortissimo mobility of CO2, as long as the existence of highly permeable zone between the two wells, it is more likely to flow through the highly permeable zone to reach the production well, even though the flow path is longer. The preferential flow shortens circulation time and reduces heat-exchange area, probably leading to early thermal breakthrough, which makes the production fluid temperature decrease rapidly. The analyses of flow dynamics of CO2-water fluid and heat may be useful for future design of a CO2-based geothermal development system.     

Experimental Study on Hydrodynamic Characteristics of Vertical-Axis Floating Tidal Current Energy Power Generation Device

To study the characteristics of attenuation, hydrostatic towage and wave response of the vertical-axis floating tidal current energy power generation device (VAFTCEPGD), a prototype is designed and experiment is carried out in the towing tank. Free decay is conducted to obtain attenuation characteristics of the VAFTCEPGD, and characteristics of mooring forces and motion response, floating condition, especially the lateral displacement of the VAFTCEPGD are obtained from the towing in still water. Tension response of the #1 mooring line and vibration characteristics of the VAFTCEPGD in regular waves as well as in level 4 irregular wave sea state with the current velocity of 0.6 m/s. The results can be reference for theoretical study and engineering applications related to VAFTCEPGD.     

基于非线性最小二乘法的石英水平摆倾斜仪格值标定

采用非线性最小二乘法对石英水平摆倾斜仪格值标定的秒采样数据进行拟合。通过Levenberg-Marquardt算法实现迭代计算过程,准确求解光记录位移信号参数并计算标定格值。仿真和台站标定实验结果表明,采用非线性最小二乘法计算倾斜仪秒采样数据的标定格值与倾斜仪校准格值的一致性较好。     

涪陵页岩气田生产套管防漏堵漏技术对策与实践

页岩气生产井投产前,都要进行大规模分段压裂,生产套管必须能承受不低于90 MPa的施工压力。2013年涪陵工区试验井组相继出现2口井稳不住压现象,导致长水平段分段压裂的储层改造工艺受限,该问题一时成为制约涪陵页岩气田钻井生产和质量的一大“瓶颈”。为此,从生产套管设计、施工、治理3个方面进行了防漏堵漏技术措施研究,并取得一些进展,较好地满足了页岩气高效开发的需要。本文介绍了涪陵页岩气一期产建套管防漏堵漏对策与实践成果,为国内类似页岩气区块的开发提供借鉴和参考。     

富拉尔基浅层水平井钻井技术应用分析

齐齐哈尔富拉尔基油田拥有丰富的浅层稠油资源,油藏埋深浅,油层薄,由于地面条件限制不能采用直井开发,长城钻探工程有限公司钻井三公司在该区块施工了7口浅层水平井。浅层水平井钻井因地面与目的层距离短,钻井完井过程中面临一些特定的技术难题。针对施工难点进行分析,从钻具组合设计、地质导向技术和钻井液优化设计三方面出发,实现安全优质高效钻井。