鄂尔多斯盆地晚古生代沉积体系演化与煤成气藏

笔者在研究鄂尔多斯盆地晚古生代沉积体系的基础上，对晚古生代生烃源岩、储集层、盖层形成与展布进行了分析，提出了沉积体系对煤成气藏的控制作用；并认为盆地内部晚古生代煤成气藏是地层封闭的岩性气藏，储集体的分布主要受河流－三角洲沉积体系的控制，特别是山2期和盒9期的河流－三角洲沉积体系的控制，它们是盆内晚古生代煤成气藏的主力气层。     

古城601井井身结构优化设计

古城地区实钻中存在表层窜冒、却尔却克组大段难钻“黑被子”地层、H2S、卡钻、井漏、溢流、井塌、地层压力温度高等技术难点，导致该区块钻井周期长、钻井成本高。针对古城地区地质特点，结合古城601井钻井目的及完井方式，综合考虑地层压力、必封点等井身结构设计关键点，在保障安全和质量的前提下，对古城601井进行了井身结构优化设计，并经实钻验证该设计思路合理，为古城地区井身结构设计提供了新思路。     

盖层的研究方法及其在油气勘探中的意义

本文系统地介绍了盖层封闭能力研究和评价方法,确定了12项主要参数,并从油气勘探的角度出发,将盖层分类与油气富集相联系,认为区域和地区性油气盖层决定了油气富集的层位和地区,局部盖层封闭能形成油气藏,而临时盖层只有在特定的地质条件下才具有勘探意义。最后以南华北地区上古生界盖层评价为例,说明了盖层研究在油气勘探中的意义,并提出了具体的评价意见。     

On the potential impact of harbour seal predation on the cod population in the eastern North Sea

Increasing Scandinavian harbour seal populations during the last decades coincide in time with the collapse of the cod fishery. Assumptions of a causal relationship have led to claims favouring re-introduction of seal hunting. Proposals for ‘adaptive management’ often assume that decimating seal populations will automatically favour the fishery. This argument presupposes seal predation to be sufficiently large to have a measurable impact on the fish population. The potential magnitude of the cod-seal interaction was analysed using data on harbour seal abundance, feeding habits and compiled information on cod life history and cod landing statistics. A size-structured life history matrix for the cod population was applied and the size-specific prey preferences of harbour seals were taken into account. Estimated seal predation was small compared to both the landings by the fishery, and to minimum estimates of the total cod population. Furthermore, since the size classes of cod targeted by seals have low reproductive values, the impact of seal predation on cod production will be further reduced. Our analyses suggest harbour seals have a negligible impact on the cod fishery.     

The sequential megafaunal collapse hypothesis: Testing with existing data

Springer et al. [Springer, A.M., Estes, J.A., van Vliet, G.B., Williams, T.M., Doak, D.F., Danner, E.M., Forney, K.A., Pfister, B., 2003. Sequential megafaunal collapse in the North Pacific Ocean: an ongoing legacy of industrial whaling? Proceedings of the National Academy of Sciences 100 (21), 12,223–12,228] hypothesized that great whales were an important prey resource for killer whales, and that the removal of fin and sperm whales by commercial whaling in the region of the Bering Sea/Aleutian Islands (BSAI) in the late 1960s and 1970s led to cascading trophic interactions that caused the sequential decline of populations of harbor seal, northern fur seal, Steller sea lion and northern sea otter. This hypothesis, referred to as the Sequential Megafaunal Collapse (SMC), has stirred considerable interest because of its implication for ecosystem-based management. The SMC has the following assumptions: (1) fin whales and sperm whales were important as prey species in the Bering Sea; (2) the biomass of all large whale species (i.e., North Pacific right, fin, humpback, gray, sperm, minke and bowhead whales) was in decline in the Bering Sea in the 1960s and early 1970s; and (3) pinniped declines in the 1970s and 1980s were sequential. We concluded that the available data are not consistent with the first two assumptions of the SMC. Statistical tests of the timing of the declines do not support the assumption that pinniped declines were sequential. We propose two alternative hypotheses for the declines that are more consistent with the available data. While it is plausible, from energetic arguments, for predation by killer whales to have been an important factor in the declines of one or more of the three populations of pinnipeds and the sea otter population in the BSAI region over the last 30 years, we hypothesize that the declines in pinniped populations in the BSAI can best be understood by invoking a multiple factor hypothesis that includes both bottom–up forcing (as indicated by evidence of nutritional stress in the western Steller sea lion population) and top–down forcing (e.g., predation by killer whales, mortality incidental to commercial fishing, directed harvests). Our second hypothesis is a modification of the top–down forcing mechanism (i.e., killer whale predation on one or more of the pinniped populations and the sea otter population is mediated via the recovery of the eastern North Pacific population of the gray whale). We remain skeptical about the proposed link between commercial whaling on fin and sperm whales, which ended in the mid-1960s, and the observed decline of populations of northern fur seal, harbor seal, and Steller sea lion some 15 years later.     

贝尔凹陷布达特群垂直裂缝垂向封闭性演化特征

通过岩心观察和成像测井资料分析,发现贝尔凹陷布达特群垂直裂缝较发育,其形成与分布受断裂控制。利用SiO₂或CaCO₃沉淀胶结所需要的镜质体反射率值,对贝尔凹陷布达特群垂直裂缝目前垂向封闭性进行了评价。凹陷大部分地区开启,仅在凹陷少部分地区封闭,封闭区在凹陷中部呈环带分布,在凹陷边部呈条带分布。贝尔凹陷布达特群垂直裂缝现今垂向封闭性差于地质历史时期垂向封闭性,油气保存条件变差,造成油气大量散失,这可能是目前贝尔凹陷能在布达特群找到一批油气藏的重要原因之一。     

天然气水合物保真取心装置内部密封技术分析

摘要：在海底天然气水合物地层钻探中,利用压力岩心取样器(PCS)获取保压岩心对于后续相关的处理和分析非常重要。首先回顾了国内保压保温取心器相关研究现状,然后从PCS取样腔内部球阀和O型圈等密封结构的特点分析了其内部上、下两部分的密封技术。在综合分析国内两种取样器密封结构特点的基础上,结合岩心现场处理与分析的特点,对PCS与上述两种取样器的密封技术进行了探讨,为取样器的密封设计、岩心现场压力和温度的保持以及保压岩心的保真转移提出了几点建议。