Influence of Hydraulic Fracturing on Overlying Aquifers in the Presence of Leaky Abandoned Wells          下载免费PDF全文

Joshua W. Brownlow  Scott C. James  Joe C. Yelderman Jr. 《Ground water》2016,54(6):781-792

The association between hydrocarbon‐rich reservoirs and organic‐rich source rocks means unconventional oil and gas plays usually occur in mature sedimentary basins—where large‐scale conventional development has already taken place. Abandoned wells in proximity to hydraulic fracturing could be affected by increased fluid pressures and corresponding newly generated fractures that directly connect (frac hit) to an abandoned well or to existing fractures intersecting an abandoned well. If contaminants migrate to a pathway hydraulically connected to an abandoned well, upward leakage may occur. Potential effects of hydraulic fracturing on upward flow through a particular type of leaky abandoned well—abandoned oil and gas wells converted into water wells were investigated using numerical modeling. Several factors that affect flow to leaky wells were considered including proximity of a leaky well to hydraulic fracturing, flowback, production, and leaky well abandonment methods. The numerical model used historical records and available industry data for the Eagle Ford Shale play in south Texas. Numerical simulations indicate that upward contaminant migration could occur through leaky converted wells if certain spatial and hydraulic conditions exist. Upward flow through leaky converted wells increased with proximity to hydraulic fracturing, but decreased when flowback and production occurred. Volumetric flow rates ranged between 0 and 0.086 m³/d for hydraulic‐fracturing scenarios. Potential groundwater impacts should be paired with plausible transport mechanisms, and upward flow through leaky abandoned wells could be unrelated to hydraulic fracturing. The results also underscore the need to evaluate historical activities.  相似文献   

Entanglements of marine mammals and seabirds in central California and the north-west coast of the United States 2001-2005     

Emma Moore  Shannon Lyday  Kate Litle  Hannah Nevins  Joe Mortenson  Melanie Piazza  Derek Lee  Sarah Allen 《Marine pollution bulletin》2009,58(7):1045-1051

Entanglement records for seabirds and marine mammals were investigated for the period 2001-2005. The entanglement records were extracted from databases maintained by seven organizations operating along the west coast of the United States of America. Their programmes included beach monitoring surveys, rescue and rehabilitation and regional pinniped censuses. Records of 454 entanglements were documented in live animals and in carcasses for 31 bird species and nine marine mammal species. The most frequently entangled species were Common Murres, Western Gulls and California sea lions. The entanglement materials identified were primarily fishing related. Entanglements were recorded every year suggesting that although the incidence level differs annually, entanglement is a persistent problem. It is recommended that each programme records details in standardized categories to determine entanglement material sources. Numbers of entanglements observed during these surveys are likely to be a conservative view of the actual entanglement rate taking place at sea.  相似文献   

A numerical study of the summertime flow around the Luzon Strait   总被引：3，自引：0，他引：3  

Ching-Sheng Chern  Joe Wang 《Journal of Oceanography》1998,54(1):53-64

Luzon Strait, a wide channel between Taiwan and Luzon islands, connects the northern South China Sea and the Philippine Sea. The Kuroshio, South China Sea gyre, monsoon and local topography influence circulation in the Luzon Strait area. In addition, the fact that the South China Sea is a fairly isolated basin accounts for why its water property differs markedly from the Kuroshio water east of Luzon. This work applies a numerical model to examine the influence of the difference in the vertical stratification between the South China Sea and Kuroshio waters on the loop current of Kuroshio in the Luzon Strait during summer. According to model results, the loop current’s strength in the strait reduces as the strongly stratified South China Sea water is driven northward by the southwest winds. Numerical results also indicate that Kuroshio is separated by a nearly meridional ridge east of Luzon Strait. The two velocity core structures of Kuroshio can also be observed in eastern Taiwan. Moreover, the water flowing from the South China Sea contributes primarily to the near shore core of Kuroshio.  相似文献   

The holocene: An interdisciplinary journal foucusing on recent environmental change. John A. Matthews (Editor), Volume 1 (1991) and Volume 2 (1992), Edward Arnold,Publishers, 284 pp. (Vol. 1) and 285 pp. (Vol. 2). $63.00 annual subscrption (paperbound)     

Joe Alan Artz 《Geoarchaeology》1993,8(5):431-433

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New uses for England's old airfields     

Nick Gallent  Joe Howe  Philip Bell 《Area》2000,32(4):383-394

Summary This article examines the process of airfield re-use across rural England, highlighting the framework and realities of procedural planning control. In doing so, it illustrates how the re-use of. airfield sites in the countryside raises issues of more general concern and mirrors wider debates within the sphere of development planning. In short, we are concerned with both opportunities for land re-cycling on rural airfields and the debates which are likely to emerge as additional sites are re-developed.  相似文献   

The origin and persistence of alpine vernal ponds in mineral soils     

Violet Harrison-Day  Joe Atkinson  Jamie B. Kirkpatrick 《地球表面变化过程与地形》2019,44(11):2202-2210

Little is known of the processes that create and maintain vernal ponds in mineral soils in alpine environments. On the Central Plateau, Tasmania, we tested the hypotheses that vernal pond complexes on mineral soils formed in response to the underlying topography of a glacio-fluvial plain; relate to present day topography; resulted from past damming by organic accumulation; are moulded by wind. The underlying topography did not relate to the surface ponds, nor were they on steeper slopes than adjacent areas without ponds. The morphology of the ponds and the morphological and edaphic characteristics of the pond complexes and adjacent areas are consistent with an origin by organic material damming. The strongest winds orientate most ponds, rather than the aspect of the slope. Sediments were preferentially caught on sticky traps to the northeast of the ponds, away from fierce prevailing southwesterly winds. Temperature measurements and fortnightly observation showed non-concordant patterns of variation in water levels in the ponds. We deduce that the complexes of vernal ponds may have formed in previous moister conditions more favourable to organic matter accumulation, possibly in the early Holocene, and are maintained by a faster rate of accumulation of mineral and organic particles in the tussock grassland adjacent to the ponds than in the ponds themselves. © 2019 John Wiley & Sons, Ltd.  相似文献   

Spatial Risk Analysis of Hydraulic Fracturing near Abandoned and Converted Oil and Gas Wells          下载免费PDF全文

Joshua W. Brownlow  Joe C. Yelderman Jr.  Scott C. James 《Ground water》2017,55(2):268-280

Interaction between hydraulically generated fractures and existing wells (frac hits) could represent a potential risk to groundwater. In particular, frac hits on abandoned oil and gas wells could lead to upward leakage into overlying aquifers, provided migration pathways are present along the abandoned well. However, potential risk to groundwater is relatively unknown because few studies have investigated the probability of frac hits on abandoned wells. In this study, actual numbers of frac hits were not determined. Rather, the probability for abandoned wells to intersect hypothetical stimulated reservoir sizes of horizontal wells was investigated. Well data were compiled and analyzed for location and reservoir information, and sensitivity analyses were conducted by varying assumed sizes of stimulated reservoirs. This study used public and industry data for the Eagle Ford Shale play in south Texas, with specific attention paid to abandoned oil and gas wells converted into water wells (converted wells). In counties with Eagle Ford Shale activity, well‐data analysis identified 55,720 abandoned wells with a median age of 1983, and 2400 converted wells with a median age of 1954. The most aggressive scenario resulted in 823 abandoned wells and 184 converted wells intersecting the largest assumed stimulated reservoir size. Analysis showed abandoned wells have the potential to be intersected by multiple stimulated reservoirs, and risks for intersection would increase if currently permitted horizontal wells in the Eagle Ford Shale are actually completed. Results underscore the need to evaluate historical oil and gas activities in areas with modern unconventional oil and gas activities.  相似文献   

Spatiotemporal Distribution of Dissolved Heavy Metals in Gyeonggi Bay,Korea     

Sojung Park  Mansik Choi  Dongjun Jang  Dongjin Joe  Kyunggue Park  Hyojin Lee  Junsik Woo  Taeha Kim  Jongkyu Park 《Ocean Science Journal》2020,55(1):69-84

In this study, we investigated the spatial and temporal distribution of heavy metals and nutrients in Gyeonggi Bay, Korea, to determine their present statu  相似文献   

南海东北部海域次表层水与中层水之流径     

王胄  陈庆生 《热带海洋学报》1997,(2)

1992年春季以及1994年夏季，台湾海峡两岸曾同时出动多艘研究船在南海东北部海域协力执行了两次较大区域的水文调查作业。根据温盐曲线之类聚情形，发现盐温变率比（即温盐曲线斜率之倒数）是除了盐度极大值与盐度极小值外另一个简单又好用的温盐特征参数。此值乍视之下仅与温盐曲线之形状有关，但因其隐涵了时间的效应，故可有效反映出水团之变性程度，对分析、推断水团之流径甚有助益。经分析、对比温盐参数与动力高度之水平分布，发现1992年春季观测时之地转流场与温盐参数二者趋势不甚一致，但1994年夏季之测情却有很好的共通性，似乎表示后者之流况系处于稳定状态，因此观测现象应较具代表性。资料亦显示：不论春、夏，在吕宋岛西北角与东沙群岛之间的广大海域主要是受成群的气旋型环流所控制，此气旋群之范围因季节而异，夏季时其势力较向东、向北扩展，因而在巴士海峡、巴林塘海峡阻挡住黑潮区之外洋次表层与中层水团向西伸展，但外洋水团仍可在台湾岛南端逸入南海东北部，然后被南海内部流系辗转带往南海腹地。春季时，外洋水团虽可占据气旋群环流场东北方之台湾西南外海，但并未见能长驱直入南海内部者，仅有部分经变性后之外洋水被气旋群西侧之环流带往南海中部，表示逸入过程是南海与西菲律  相似文献   

On the contribution of groundwater to streamflow in laterite catchments of the Darling Range,south-western Australia     

Andrew Haden Grigg  Joe Kinal 《水文研究》2020,34(25):5070-5084

In deeply weathered laterite catchments of the Darling Range in south-western Australia, the direct contribution (i.e., discharge) of permanent groundwater to streamflow has long been considered as minor. Instead, downslope shallow throughflow was thought to dominate, generating more than 90% of streamflow. We used a chemical hydrograph separation approach to estimate annual groundwater discharge for three catchments over periods of up to 39 years, and found that direct groundwater contributions to streamflow were far more variable across catchments and through time than has previously been acknowledged. The estimated proportion of annual streamflow sourced directly from groundwater ranged from 0 to 93% and was related linearly to the size of the groundwater discharge area in the catchment valley floor. In contrast, contributions from shallow sources including shallow throughflow varied primarily and linearly with annual rainfall. However, the response to rainfall was “amplified” in a predictable way by the size of the groundwater discharge area, consistent with the variable source area concept. We derived a functional relationship between catchment annual rainfall-runoff ratio and groundwater discharge area and successfully applied this to a further four catchments, inferring that the results were broadly applicable across the Darling Range. The implications for an improved understanding of streamflow generating processes in the study region, and for laterite catchments generally, are discussed.  相似文献