地下资源开采与诱发地震：现状与进展

页岩气、地热等清洁能源正成为全球能源开发日益重要的组成部分,也是我国未来能源产量增长的主体,对保障能源资源安全、支撑双碳目标意义重大。然而随着页岩气、地热等地下工业开采活动规模的不断扩大,由此引发的地震灾害问题正日益受到人们的关注。强化工业活动与诱发地震关系研究、管控相关诱发地震灾害风险成为全球面临的重要课题和挑战。基于此,笔者等调研了工业活动诱发地震的全球典型案例,系统介绍了不同国家(美国、加拿大和韩国)工业活动诱发地震的现状及其差异,并对流体注入诱发地震的主要途径、物理机制、相关作业参数和诱发地震关系等做了全面的综述。发现诱发地震不仅与流体注入参数(体积、速率等)相关,还受控于特定的区域地质背景和断裂条件。合理管控地震灾害风险、促进相关能源的开采,应该统筹开采区地质地球物理的综合调查和开采过程的动态监测。     

中国岩浆硫化物矿床的主要类型

母岩浆侵入现存空间之前，在深部就已发生了熔离作用和部分结晶作用，致使母岩浆分离为不含矿岩浆、含矿岩浆、富矿岩浆和矿浆，然后对现存空间一次或多次贯入成矿。这种成矿作用是小岩体成大矿的必备条件，这种深部熔离—贯入矿床，是中国最主要的岩浆硫化物矿床类型，也是世界主要的岩浆硫化物矿床类型之一     

NIMBY localism and national inequitable exclusion alliances: The case of syringe exchange programs in the United States

Syringe exchange programs (SEPs) aim to reduce the harm associated with injection drug use (IDU). Although they have been accepted as critical components of HIV prevention in many parts of the world, they are often unwelcome and difficult to set up and maintain, even in communities hardest hit by IDU-related HIV transmission. This research examines socio-cultural and political processes that shape community and institutional resistance toward establishing and maintaining SEPs. These processes are configured and reinforced through the socio-spatial stigmatizing of IDUs, and legal and public policy against SEPs. Overarching themes the paper considers are: (1) institutional and/or political opposition based on (a) political and law enforcement issues associated with state drug paraphernalia laws and local syringe laws; (b) harassment of drug users and resistance to services for drug users by local politicians and police; and (c) state and local government (in)action or opposition; and (2) the stigmatization of drug users and location of SEPs in local neighborhoods and business districts. Rather than be explained by “not in my back yard” localism, this pattern seems best conceptualized as an “inequitable exclusion alliance” (IEA) that institutionalizes national and local stigmatizing of drug users and other vulnerable populations.     

Status and Advances of Abandoned Process of Wells for CO2 Geological Storage

With the rapid development of CO₂ geological storage and utilization (CCS/CCUS), the abandoned well in the sites of CCS/CCUS projects is becoming an important subject to be solved to check whether it can effectively block the residual CO₂ or not. Up to now, the abandoned process of wells in the field of oil and gas in China and abroad have gained mature operation technology and rich experience. However, in the field of CCS/CCUS, there is only a small number of global public instances about the abandoned process of operational wells of CO₂ including CO₂ injection wells and CO₂ monitoring wells, and the domestic instance is still blank. In this paper, we firstly summarized the required demands, materials, cases of operational experiences, and monitoring requirements of the abandoned process of operational wells of CO₂ in the developed countries, e.g. the Netherlands, the United States and Canada. Then, we figured out the status of the abandoned process of domestic wells in oil and gas industry. Finally, we concluded the differences of the abandoned process between operational wells of CO₂ and traditional wells of oil and gas, and proposed some recommendations for the abandoned process of operational wells of CO₂ in the current and future CCS/CCUS projects in China. This study has important implications for the upcoming abandoned process of all the operational wells at Shenhua CCS demonstration site in 2016.     

Significance of injection modes and heterogeneity on spatial and temporal dispersion of advecting particles in two-dimensional discrete fracture networks

We investigate the impact of injection mode (flux and resident injection) and heterogeneity in hydraulic properties on dispersion of advecting particles in two-dimensional discrete fracture network models, using a Monte Carlo method. We find that the injection mode has a significant effect on dispersion: The resident injection mode exhibits anomalous features of transport whereas the flux injection mode tends to Gaussian transport; this observation is easily understood by considering phase diagrams where a limited number of particles entering low velocity fractures greatly increase macrodispersion. In spite of a sizeable portion of negative longitudinal velocities, it is shown that multiple crossings are negligible when quantifying longitudinal macrodispersion. A simple probabilistic expression of particle mass balance is shown to predict well the spatial distribution of advecting particles.     

濮阳小震集中区发震机理分析与讨论

综合小震精定位和震源机制解两方面的结果,对濮阳小震集中区小震丛集活动的发震机理进行了分析.双差定位结果显示,大部分地震震源位于聊考主干断裂上,与断层的产状吻合;5次ML≥3.5地震的震源机制显示,双力偶模型可以较好地解释观测波形,小震震源机制主要为走滑型,初动符号呈象限分布;在参考了油田地质构造背景资料后,对濮阳小震集中区中、小地震活动与油田采油作业之间是否存在注水诱发关系进行了讨论.     

自贡-隆昌地区地震重新定位及P波速度结构研究

基于2007年1月～2010年8月自贡地方数字测震台网和流动台站记录的地震观测报告,对自贡-隆昌地区开展了地震精定位和速度结构反演两方面的研究工作,并结合研究区地震活动时间序列及注水井(家33井)的加压数据,探讨了注水区域及邻区地震震源深度分布、P波速度结构特征及其与家33井加压注水的关系。定位结果显示:地震的空间丛集性更加明显,集中分布在自贡(A区)、富顺-隆昌交界(B区)及隆昌(C区)等3个区域。其中距家33井西侧约20km的A区地震呈NNE向长轴展布,震源深度主要分布在5～15km;B、C区域内的地震则沿NW向长轴展布,家33井所在的B区绝大多数地震的震源深度在2～6km,即家33井的注水层位附近,呈现由NW至SE的铲形特征,并逐渐变深;位于家33井东南方向约15km的C区,地震震源深度相对B区较深,优势深度在8～15km。分析认为,A区地震活动与家33井加压注水无关,而B、C区域的地震活动却明显受到加压注水的影响。P波速度结构显示:在3km深的注水层位附近,区域B、A之间形成了1条近NS走向的高、低波速过渡带,B区地壳介质的P波速度明显高于A区,其原因是家33井出现容腔饱和,使该区地下介质具有较高含水饱和度引起的。     

对比剂不同注射方案对冠状动脉CTA图像质量的影响

目的 分析冠状动脉CTA扫描时对比剂的不同注射方案对其图像影响,寻求最佳注射方案。方法 选取240例体重相近患者随机平均分成A、B、C 3组行冠状动脉CTA扫描。A组应用双期注射方案,首次注入70ml对比剂,随后追加20ml生理盐水;B组应用双期注射方案,首次注入50ml对比剂,随后追加20ml混合剂（盐水∶对比剂为1∶1）,C组应用3期注射方案,首次注入50ml对比剂,第2期注入20ml混合剂（盐水∶对比剂为1∶1）,随后追加生理盐水20ml。评价3组CTA图像升主动脉（AO）及冠状动脉三大分支CT值比较,差异有无统计学意义,比较3组间上腔静脉、右心室硬化伪影及室间隔显示情况。结果 与A组比较,B、C两组在减少10ml对比剂情况下,3组间AO及冠状动脉三大分支CT值比较,差异无统计学意义（P>0.05）,B组上腔静脉、右心室硬化伪影高于A、C两组（P<0.05）,C组室间隔显示率高于A、B两组（P<0.05）。结论 应用第3时相对比剂注射方案,既能有效减少造影剂用量,又能保证图像质量,较好地显示室间隔,对冠状动脉疾病的诊断具有一定意义。     

Magma accumulation and segregation during regional-scale folding: The Holland’s dome granite injection complex,Damara belt,Namibia

The regional-scale, upright fold of the Holland’s dome in the Damara belt of central Namibia contains a kilometre-scale network of intrusive, highly fractionated uraniferous leucogranites. Three broadly orthogonal and intersecting sets of leucogranite sheets that intruded parallel and at right angles to the axial plane of the first-order fold can be distinguished. The granites are internally sheeted and illustrate the growth of the injection complex through the successive addition of thousands of smaller magma batches. Spatial and timing relationships point to a stepwise evolution of the injection complex. Early dilatancy-driven segregation and accumulation of granitic magmas in the core of the fold, above a basal detachment, was followed by compaction-driven segregation of a melt phase during fold tightening. The intersecting leucogranite sets provide a suitably organized permeability structure for melt segregation, while the successive injection of magma batches ensures compatibility between regional strain rates during folding and the rates of magma segregation. The three-dimensional network of melt-bearing structures further assisted regional shortening past the lock-up of the fold. The Holland’s dome injection complex illustrates the geometric complexity of magma transfer pathways and the significance of regional-scale folding for the accumulation, segregation and fractionation of granitic magmas in suprasolidus crust.     

Potential assessment of CO2 geological storage based on injection scenario simulation: A case study in eastern Junggar Basin

Carbon Capture and Storage (CCS) is one of the effective means to deal with global warming, and saline aquifer storage is considered to be the most promising storage method. Junggar Basin, located in the northern part of Xinjiang and with a large distribution area of saline aquifer, is an effective carbon storage site. Based on well logging data and 2D seismic data, a 3D heterogeneous geological model of the Cretaceous Donggou Formation reservoir near D7 well was constructed, and dynamic simulations under two scenarios of single-well injection and multi-well injection were carried out to explore the storage potential and CO₂ storage mechanism of deep saline aquifer with real geological conditions in this study. The results show that within 100 km² of the saline aquifer of Donggou Formation in the vicinity of D7 well, the theoretical static CO₂ storage is 71.967 × 10⁶ tons (P50)^①, and the maximum dynamic CO₂ storage is 145.295 × 10⁶ tons (Case2). The heterogeneity of saline aquifer has a great influence on the spatial distribution of CO₂ in the reservoir. The multi-well injection scenario is conducive to the efficient utilization of reservoir space and safer for storage. Based on the results from theoretical static calculation and the dynamic simulation, the effective coefficient of CO₂ storage in deep saline aquifer in the eastern part of Xinjiang is recommended to be 4.9%. This study can be applied to the engineering practice of CO₂ sequestration in the deep saline aquifer in Xinjiang.