Time and Temperature Factors in Construction of Rock Strength Criteria

Using the synthesis of the kinetic concept on solid strength and the Coulomb - Mohr strength theory as the base, the failure conditions taking into account the time and temperature factors are obtained.     

气腿式凿岩机的使用和故障排除的几种方法

YT— 2 4型气腿式凿岩机在煤矿掘进中广泛使用 ,要科学地使用操作和维护 ,出现机器凿岩速度降低、水针折断、气水联动失灵等故障 ,应分析原因 ,采用有效的措施排除 ,保证生产的顺利进行     

国内外钻探用金刚石复合片性能的研究

主要介绍国内外金刚石复合片性能及采用四高复合片钻探硬岩的初试,为快速钻探提供一个新的途径.     

岩盐钻井水溶双井连通开采工艺的研究与推广

文章就全国井矿盐采区多年的开采工艺技术，进行了系统的研究与总结，并提出了岩盐钻井水溶开采双井连通的各种开采工艺及其关键技术，具有很强的适用性和推广价值。     

非均匀裂缝性油藏压力动态

在介绍具有连续基质颗粒大小分布和孔间表皮裂缝性油藏的不稳定压力分析模型的同时。提出了代表实际变化的裂缝密度和均匀性油藏的基质岩块大小分布概率密度函数，给出Laplace空间井筒压力解。该理论通过裂缝跨度变化拓宽了以前的双孔隙油藏模型，在不考虑孔间表皮的情况下，对非均匀裂缝性油藏压力动态进行了分析。     

高应力复合型软岩巷道支护技术研究

以某矿井底车场巷道为例，通过对围岩物化分析、力学参数、地应力测试，现场工程地质调查及巷道破坏特征分析，针对该矿软岩巷道围岩变形量大和流变变形显著这两个特点，提出了一次支护采用强力锚喷网、二次支护采用锚注支护是适合该矿岩体特点的合理支护形式，并在该矿西大巷延拓及井底车场巷道、硐空修复中成功应用，取得了良好的技术经济效果。     

PRO——一种新的地震资料处理方法

PRO(影像的参数展开)技术是由俄罗斯地球物理学家开发的一种崭新的地震资料处理技术。本文从PRO基本原理入手,简单介绍了PRO的速度分析原理。PRO速度分析和成像均以信号的椭圆展开和参数展开为基础,其中参数展开方法考虑波型转换、介质的横向不均匀造成传播速度的变化。该技术抛开了传统共中心点叠加的思想,从根本上解决了以CMP方法为基础的传统地震处理技术遇到的困难。通过模型与实例分析对比,PRO比传统CMP方法更优越。     

Use of pyrogenic silicas for petroleum oil polar fraction characterisation. Fourier transform infrared spectroscopy and microelectrophoresis studies

In the power transformer, the presence of polar or charged species in the insulating oil can cause failure and electric discharges. Solid substrates such as silica can be used to extract the polar species and to refine the oil in order to prevent future failure in the power transformer. However, the use of silica for petroleum oil separation and refining will depend on the silica characteristics such as surface charge, surface composition, specific surface area and particle size.Various pyrogenic silicas having various specific surface areas (49-200 m² g⁻¹) and particle sizes (207-500 nm) were used to extract the polar fractions from the neat transformer insulating oils (a new, NO, and used, UO2, oils). The oil covered silica samples were investigated by diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy in the range 4000-600 cm⁻¹. The bare silica surfaces present two main hydroxyl components, a sharper peak at 3745 cm⁻¹, I₃₇₄₅, due to isolated silanols and a second broad, which spreads over 3745-3000 cm⁻¹, I_3745-3000, due to H-bonded silanols. The relative intensities of the two components, I₃₇₄₅/I_3745-3000, varied for the bare and the oil covered silicas depending on the solid surface characteristics. The adsorption of the NO polar fraction onto silica leads to strong reduction in intensity of the sharper peak in favour of the broad one. However, the adsorption of the UO2 polar fraction onto silica leads in all cases to the decrease in the intensity of the both silica OH components. Further, the UO2 adsorption on the silica leads to the apparition of a broad peak at low frequency in the region 3250-3300 cm⁻¹ which, is due to the associated phenolic groups of UO2 oil polar fraction. The analysis of the DRIFT spectra for various samples indicates that the oil polar fraction resembles to asphaltenes compounds.The microelectrophoresis method used to investigate the surface charge at the water/oil polar fraction covered silica interface, indicates negatively charged particles. Further, the negative charge increased with the pH, as resulting from the increase of the ionisation and/or the amount of the oil polar carboxylic and phenolic groups. The oil polar fraction, i.e. the asphaltene components, in contact with both the silica surface and water at high pH values rearrange, due to their amphiphilic character.Finally, the use of the silica substrates seems to be suited to extract and analyse polar species present in petroleum oil. A correlation is found between the nature of the oil, its functionalities, and the magnitude of its zeta potential value at the water/oil covered silica interface.     

Silica removal from Mokai, New Zealand, geothermal brine by treatment with lime and a cationic precipitant

Preliminary experiments using two chemicals (CaO, a quicklime, and a cationic nitrogen-bearing precipitant, EC-004) to remove silica from geothermal brine were undertaken at the Mokai geothermal plant, New Zealand. The brine was mixed with the reagent (CaO or EC-004). The reaction was studied from the start of the experiment (NRT, 0 min, no retaining time) and after 15 min (15RT) at 90 °C. The concentration of silica in the brine was initially 954 mg/l, and decreased linearly with increasing reagent concentration. When CaO is added, the silica concentration at 15RT was 200 mg/l lower than at NRT and became almost zero on addition of 1.5 g/l. In contrast, when EC-004 is added, the total silica concentration nearly reaches the solubility of amorphous silica at 90 °C. In order to prevent silica scaling in Mokai brines cooled to 90 °C, the CaO and EC-004 added should be individually adjusted to 0.5 g/l and 80 mg/l, respectively.