柴达木盆地英雄岭页岩油地质特征、评价标准及发现意义

柴达木盆地英雄岭地区古近系下干柴沟组上段页岩油获勘探重大突破,但成湖相烃源岩低有机碳含量与页岩油成因机理、页岩油评价标准、资源潜力不清等问题,制约了英雄岭页岩油评价和勘探.把英雄岭地区以富有机质纹层状页岩与灰质白云岩高频间互为特征的页岩型和混积型页岩油类型作为攻关重点,通过大量岩心、钻井、地震及化验资料分析和综合研究,...     

动水条件下巷道灾害治理技术

长期动水条件作用下巷道会发生局部渗水、漏水以及顶、底板发生破坏,严重影响巷道服务年限,并造成重大安全隐患,针对这种环境下巷道破坏的特点与机理,通过大量工程实例对比,提出了注浆结合锚杆支护对巷道进行综合治理,增强巷道整体稳定性与防渗性,从而延长巷道服务年限,对相关工程的维护具有指导意义。     

Two-Phase (Air and Water) Flow through Rock Joints: Analytical and Experimental Study

This research study deals with the characterization of two-phase flow in a fractured rock mass. A comprehensive mathematical model with which to predict the quantity of each flow component in a single joint is developed. A joint with two parallel walls filled with layers of water and air (stratified) is analyzed. The effects of mechanical deformation of the joint, the compressibility of fluids, the solubility of air in water, and the phase change between fluids have been taken into account to develop analytical expressions which describe the behavior at the air–water interface. The model was calibrated using a newly designed two-phase (high-pressure) triaxial cell. Tests were conducted on fractured hard rock samples for different confining pressures with inlet water and inlet air pressures. As in single-phase flow, it was found both experimentally and theoretically, that the flow quantities of each phase decreases considerably with an increase in confining stress. The results also confirm that the effect of joint deformation and compressibility of fluids governs the flow volume of two-phase flow. Good agreement was obtained between the experimental data and numerical predictions.     

济阳坳陷渤南洼陷湖相碳酸盐岩成烃特征

在济阳坳陷渤南洼陷沙河街组下部发育了一类以泥质灰岩、泥灰岩和泥质白云岩为主的富含有机质的湖相碳酸盐岩。其有机显微组分以矿物沥青基质和沥青质体为主;可溶有机质中饱和烃/芳烃值低,非烃和沥青质含量高;分子标志物的原始生物骨架结构保存好,重排类化合物含量低,有机含硫化合物丰富,并发育诸多特殊类型的标志物。湖相碳酸盐岩所表现出的这些特征与其特殊的沉积环境密切相关,硫酸盐还原菌、绿硫菌、蓝细菌等微生物是该类烃源岩形成的重要物质基础。综合考虑沉积相差异和成熟度的影响,可将二苯并噻吩与菲的比值大于1、重排甾烷及C₃₀重排藿烷极不发育、富含2-甲基藿烷和30-降藿烷系列等条件作为判识湖相碳酸盐岩生油的标志。渤南洼陷湖相碳酸盐岩至少出现过两期生烃高峰,具备形成大规模商业性油藏的能力,可以成为我国陆相湖盆下一步优选的勘探目标。     

Microbial and Waterflooding of Fractured Carbonate Rocks: An Experimental Approach

Fractures and fractured zones require special attention while formulating a reservoir development plan. They may improve or hinder the oil production. Conductive fracture rocks may provide the required permeability to drain an oil saturated low permeability rock matrix. Low sweep efficiency of many oil reservoirs is the result of channelling of injected water through high permeability zones that are normally associated with naturally fractured systems in heterogeneous reservoirs. In this case, a substantial amount of effort needs to be focused on improving the distribution of injected water in the wellbore through different treatments, such as using gelling agents, cements, cross-linked polymer and emulsions. Other alternatives such as microbial and surfactant based methods have been proposed. This paper presents the results of research conducted on thermophilic bacteria that were obtained from UAE local environment. Coreflooding experiments were conducted on fractured single cores to show the effectiveness of microbial treatment. Different fracture angle orientations of 45°, 90°, and 180° relevant to the axis of the flow were investigated. The effect of matrix permeability on the treatment was also studied. A comparison between water flooding and microbial flooding of fractured systems was conducted. A non-invasive imaging technique—Scanning Electron Microscopy (SEM)—was employed to visualize changes on the surface of the fracture as a result of bacteria flow through the system.     

Slope stability problems of the weak rocks in the Asarsuyu pass of the Anatolian motorway

 The Anatolian motorwaythrough the Asarsuyu Valley passes across landslides formed in amphibolites, metagranites and metadiorites which have been extensively disturbed by past fault movements. The investigations indicated that the instabilities in the valley could affect the proposed motorway. An attempt was made to establish the shear strength values of the 1200×750×130 m Kom Rock Slide using the Hoek and Brown equation. The work indicated that this was not applicable in the highly sheared material along the major fault zones. 28 February 1998 · Accepted: 9 June 1998     

Establishment of an empirical correlation for estimating the thermal conductivity of igneous rocks

A correlation to predict the thermal conductivity of andesitic igneous rocks is developed from measured data on drill cores from wells from the Los Azufres geothermal field, Mexico. The correlation was developed from density, porosity, and thermal conductivity. Seventeen determinations were made on drill cores extracted at varying depths from 12 wells. Thermal conductivity varied from 1.05 to 2.34 W · m^–1 · K^–1, while bulk density varied from 2050 to 2740 kg · m^–3 and grain density varied from 2610 to 2940 kg · m^–3. Total porosity varied from 1.9 to 24.7%. Two polynomial regressions, one linear and one quadratic, were tested on the thermal conductivity-times-bulk density product, with total porosity as the independent variable. The correlation coefficients and residual mean square deviations were 0.83 and 0.00491 for the linear fit and 0.87 and 0.00425 for the quadratic model, respectively. For porosities up to about 18%, both models showed very close predictions, but for larger values, the quadratic model appeared to be better and it is recommended for the porosity range from 0 to 25%. Furthermore, density and porosity may be determined from drill cuttings, which are more readily available than cores.Paper presented at the Tenth Symposium on Thermophysical Properties, June 20–23, 1988, Gaithersburg, Maryland, U.S.A.     

DI-B experiment: planning, design and performance of an in situ diffusion experiment in the Opalinus Clay formation

The DI-B experiment is a long-term, natural-scale, in situ diffusion experiment, which is being performed in the Opalinus Clay formation at the Mont Terri Underground Rock Laboratory (URL), in Switzerland, employing nonradioactive tracers. One of the key aspects to be addressed for nuclear waste repository safety assessment purposes is the understanding of the transport mechanisms of the radionuclides contained in the radioactive waste. Consolidated clay formations display very low water hydraulic conductivities, so it is expected that the predominant transport process will be diffusion.The experimental set-up has been designed to withstand the site conditions and for monitoring and recording several physicochemical parameters (pH, conductivity, oxidation–reduction potential), as well as the pressures in the circuit and for the long-distance monitoring of the data acquisition system.The tracer selection has been made based on previous investigations carried out at CIEMAT, including a literature survey, laboratory sorption experiments and hydrogeochemical modeling for determining tracer stability under the physicochemical conditions to be expected in the site. The final selection includes ⁶Li, ⁸⁷Rb, D (as D₂O) and I (as I⁻). Hydrogeochemical modeling confirmed the stability of all the tracers selected. Batch sorption experiments showed that no sorption in the rock occurred in the case of ⁶Li, D and I (conservative tracers), whereas ⁸⁷Rb was 100% sorbed. However, ⁸⁷Rb was chosen because of its analogy with Cs, a relevant radionuclide commonly present in the nuclear spent fuel.Diffusion experiments have been carried out at laboratory scale with Opalinus Clay samples to provide diffusion parameters for modeling purposes. Effective diffusion coefficients, perpendicular and parallel to the bedding planes of the rock, respectively, were (1.68± 0.42)×10⁻¹¹ and (4.02± 0.30)×10⁻¹¹ m²/s for tritium, and (2.70± 0.27)×10⁻¹² and (1.38± 0.49)×10⁻¹¹ m²/s for iodide. Additional through-diffusion experiments (parallel to the bedding) were performed with the nonsorbing tracer ³⁶Cl⁻, in order to check the results obtained for iodide. The effective diffusion coefficient measured for chloride ions was (1.18± 0.27)×10⁻¹¹ m²/s, which is practically equal to the value obtained for iodide.Preliminary diffusion calculations have been carried out using two transport codes: GIMRT and CORE^2D, with conservative and nonconservative tracers, using effective diffusion coefficients (D_e) obtained experimentally in the laboratory (through-diffusion experiments) or selected from the literature. The diffusion profiles obtained from the calculations showed slight variations, which were consistent with the different modeling approaches employed. The predictive modeling results have been used to determine the initial tracer concentration that should be added to the circuit to assure well-defined profiles at the end of the experiment.This long-term in situ diffusion experiment will also provide useful data for the interpretation of previous diffusion experiments performed at the Mont Terri URL.     

中等含水层下留设防砂煤柱开采的试验与研究

百善煤矿主采煤层上方直接覆盖有22－27m的砂砾石含水层,严重威胁矿井的安全生产。为了安全合理地开采,进行了矿区水文地质和上覆岩层岩石力学、水理性质以及“两带”高度试验。结果表明：含水层内含黏量较高,垂直渗透能力较弱;所留煤柱属软弱或极软弱类型;风化带内黏土矿物含量较大;吸水后体积膨胀,再生隔水能力强;受采动影响后,具阻水和抑制导水裂隙带继续发展的双重作用;根据以上研究结果,取得了将垂高50m的防水煤柱缩小到12－20m防砂、防塌煤柱的技术突破,安全地多采煤600多万t,经济效益显著。