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91.
According to the preliminary geological data of gas hydrate bearing-sediments (GHBS) at site GMGS3-W19 in the third Chinese expedition to drill gas hydrates in 2015, a production model using three different recovery pressures was established to assess the production feasibility from both production potential and geomechanical response. The simulation results show that for this special Class 1 deposit, it is a little hard for gas production rate to reach the commercial extraction rate because the degree of hydrate dissociation is limited due to the low reservoir permeability and the permeable burdens. However, the free gas accumulating in the lower part of the GHBS can significantly increase gas-to-water ratio. It also generates many secondary hydrates in the GHBS at the same time. Decreasing the well pressure can be beneficial to gas recovery, but the recovery increase is not obvious. In term of geomechanical response of the reservoir during the gas recovery, the permeable burdens are conducive to reduction of the sediment deformation, though they don't facilitate the gas recovery rate. In addition, significant stress concentration is observed in the upper and lower edges of GHBS around the borehole during depressurization because of high pressure gradient, and the greater the well pressure drop, the more obvious the phenomenon. Yield failures and sand production easily take place in the edges. Therefore, in order to achieve the purpose of safe, efficient and long-term gas production, a balance between the production pressure and reservoir stability should be reached at the hydrate site. The production pressure difference and sand production must be carefully controlled and the high stress concentration zones need strengthening or sand control treatment during gas production. Besides, the sensitivity analyses show that the hydrate saturation heterogeneity can affect the production potential and geomechanical response to some extent, especially the water extraction rate and the effective stress distribution and evolution. Increasing GHBS and its underlying free gas formation permeabilities can enhance the gas production potential, but it probably introduces geomechanical risks to gas recovery operations. 相似文献
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93.
Michael Ekers 《Geoforum》2009,40(3):303-315
This article attempts to empirically demonstrate how the struggle for bourgeois hegemony in depression-era British Columbia, Canada, was fought for through the production of new natures. Bringing together Antonio Gramsci’s conceptualization of hegemony with marxist understandings of political ecology, I examine how the legitimacy of particular groups’ dominance over subordinate groups and the survival of specific social relations was built and contested through the (re)making of the material-symbolic landscape. However, I also take seriously Stuart Hall’s argument that we must take note of the multi-dimensional character of hegemony by paying attention to the entanglement of class, gender and ecological relations during the 1930s. In order to demonstrate these arguments I examine the economic, social, moral and ecological crisis that rippled across the socionatural fabric of B.C. during the depression years. I detail how the federal and provincial states responded to the interlaced crises of class, gender and ecological relations through launching a series of public works programs and training programs. These projects were intended to modernize the forestry industry and remake unemployed men in body and soul. In doing so, I demonstrate how ideologies regarding nature come to be both enrolled in the struggle for hegemony and materialized in the making of the forestscape. By weaving theoretical insights through the socionatural history of British Columbia, I demonstrate how a gramscian sensibility pushes us to take seriously the relationality of socionatural processes and the embededdness of concepts in material histories. 相似文献
94.
本文就朔州市2000年降水不多而粮食获得丰收,分析了年内4~9月光、热、水对农作物的利弊影响,提出了预报服务中应重视作物关键生育期的天气预报,以利于农业生产巧用天时,趋利避害,夺取丰收。 相似文献
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96.
Emanuel Mazor 《Pure and Applied Geophysics》1978,117(1-2):262-275
Noble gases were studied in six wells, located on a 4.5 km south to north section across the Larderello field. Depth of wells, flow and gas/steam ratios are known to increase from south to north. Exploitation progressed in the same direction. The following noble gas patterns are observable: (a) Atmospheric Ar, Kr and Xe reflect productions of gas-depleted water at Colombaia 2 and progressively more gas-enriched steam towards the Gabbro wells. (b) Radiogenic4He and40Ar are observed in increasing concentrations from south to north. (c) The radiogenic and atmospheric gases reveal a positive correlation, indicating that the recharging water enters deep into the system, and gets well mixed with the radiogenic gases prior to the steam separation. (d) Gas contents and relative abundances of radiogenic argon decrease with production, thus supplying markers for the degree of exploitation in a well and a guide for optimum well spacing. (e) Excess neon over argon is observed and discussed in terms of crustal origin versus possible fractionation of atmospheric noble gases due to pertial steam separation. 相似文献
97.
把油水同层作为有利试油层位含油气性的下限,通过提取试油层位的4种地质参数,利用两总体判别分析法,建立有利试油层位和不利试油层位的判别函数,根据判别函数并结合测井解释资料对试油层位进行优选. 相似文献
98.
99.
通过对广西防城港市企沙盐场1996-2005年近10年的原盐产量与气象条件的关系进行分析,得出影响海水制盐的主要气象因子是降水、蒸发量、气温、大风,并提出各种气象条件下的生产对策及气象部门对盐业服务的思路和设想。 相似文献
100.
《Geoforum》2015
Additive manufacturing (or 3D printing) is a comparatively new and evolving form of production that has the potential to transform the geographies of manufacturing. While this technology has garnered significant hype in the popular media, the topic has been virtually ignored in academic circles outside of business- and industry-specific, technology-oriented journals. Given its prospective impacts on the secondary sector and the potential for geographers to explore these transitions, this article provides a discussion of the possible opportunities for theoretical explorations and research into the place-based facets of additive manufacturing and its impacts on, or integration with, traditional manufacturing. In particular, we examine the spatial ramifications of this technology on supply, demand, innovation, global production networks, and the role of the state juxtaposed against contemporary insights pertaining to advances in additive manufacturing. 相似文献