共查询到18条相似文献，搜索用时 109 毫秒
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分析了我国深水钻井的现状和未来发展趋势,调研分析了深水钻井所面临的困难和深水钻井液必须具备的基本性能。在理论推导并结合实践的基础上,研制了深水低温钻井液基本性能模拟实验装置、深水钻井液水合物生成与抑制评价实验装置以及深水钻井液循环与井壁稳定模拟实验装置等,并对模拟装置的实验可行性和平行性进行了验证。实验结果表明,新研制模拟实验装置控制精度较高、实验平行性较好,能够满足深水钻井液性能测定与评价的基本要求,为我国深水钻井液技术研究奠定了一定的室内实验研究基础。 相似文献
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建立南海潮波模式及其伴随同化模式,在传统二维潮波方程的基础上加入了内潮耗散项,考虑了内潮耗散对南海潮波系统的影响,在前人工作基础上,改进了内潮耗散参数化方案,并给出内潮耗散项中地形效应参数的计算公式;通过对比,本文的参数化方案比前人参数化方案能取得更为合理的模拟结果。以63个验潮站和24个TOPEX/Poseidon卫星高度计轨道交叉点处的调和常数作为观测值,利用伴随同化方法来优化模式中的底摩擦系数和内潮耗散系数。为了寻求最优的优化方案,设计了7组数值实验。实验结果表明,实验7先优化内潮耗散系数再优化底摩擦系数的模拟结果最优。利用实验7的模拟结果分析了南海M2分潮的潮波特征,与前人结果基本一致。 相似文献
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以淀粉为主要原料,合成了新型多羟基糖苷防塌剂DTG-1。对合成样品的理化性能、页岩抑制作用、水溶液活度、生物毒性以及对泥页岩半透膜膜效率的影响规律进行了测定,考察了DTG-1在淡水、盐水和饱和盐水钻井液中对钻井液流变性能和滤失造壁性能的影响,并对DTG-1稳定井壁及改善钻井液流型的作用机理进行了分析。研究表明,用淀粉合成的多羟基糖苷,具有一定的抑制泥页岩水化膨胀、分散和提高泥页岩的膜效率的作用,能有效降低钻井液的水活度,属于无毒、环保型钻井液处理剂;DTG-1对高密度钻井液具有很好的流型改善作用,用DTG-1配制的钻井液具有组成简单、流变性易调整、高温稳定性好、抗污染性强等特点。 相似文献
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在海洋深水海域,由于其沉积环境的特殊性而使得地层比较脆弱,表现为地层孔隙压力和破裂压力之间的窗口比较窄,在实施钻探作业过程中当循环当量钻井液密度接近于地层破裂压力而超过井周地层的闭合钻井液密度当量,就会形成地层呼吸效应,即正常钻进保持循环时部分钻井液进入井眼附近地层,在接立柱停止循环时这部分钻井液回吐而观察到溢流,从表象上难以判断是地层回吐还是真正发生了溢流,需要频繁使用司钻法循环出溢流来确认,这给井控作业增加额外时间和风险.此文分析了深水地层呼吸效应的形成机理,阐述在深水钻井中如何识别与判断地层呼吸,提出相应的技术措施,为深水钻井作业提供参考. 相似文献
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董昌明 LIM KAM SIAN Kenny Thiam Choy 蒋星亮 曹玉晗 嵇宇翔 王森 余洋 陆晓婕 周书逸 韦销蔚 BETHEL Brandon Justin 徐广珺 董济海 孙文金 王海丽 单海霞 王锦 王东霞 滕芳园 曹茜 谢文鸿 游志伟 王子韵 林连杰 《海洋科学进展》2022,40(4):660-683
海洋预报是进行海上活动的安全保障,海洋预报系统技术已经成为现代海洋气象业务的技术支撑。海洋观测、数据同化、数值模拟和高性能计算机等技术的进步极大地推动着海洋业务化预报的发展。采用大气数值模式（WRF）、海洋数值模式（CROCO）和海浪数值模式（SWAN）的多模式高分辨率离线耦合方式,添加南京信息工程大学“海洋数值模拟与观测实验室”团队自主研发的一系列海洋模式参数化方案,包括浪致混合参数化方案、亚中尺度参数化方案、海山诱导混合参数化方案以及涡旋诱导的沿等密度面和跨等密度面混合参数化方案,并通过同化技术和最新的人工智能技术与观测资料相结合,构建一种面向中国边缘海的风浪流多参数耦合预报系统,用于海上风电功率的预报和其他海洋灾害预警。实际观测资料的验证表明,该预报系统能较准确地模拟海上风场、海流、海温、波浪、潮汐等海洋气象要素。同时实现了按需实时可视化全景展示。 相似文献
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近海潮锋的分布与温度、盐度乃至海洋生产力的分布都存在紧密联系。基于北部湾东北部的实测数据,对比分析2016—2017年北部湾东北部海域的温度、盐度、密度等分布,并利用ROMS(Regional Ocean Model System)正压与斜压模式,计算Simpson-Hunter (S-H)参数,阐述了潮锋出现位置及其与温度、盐度和密度的关系。结果表明:北部湾东北部潮锋发生的主要区域位于雷州半岛附近,潮混合区温盐密混合较为均匀。利用ROMS模式计算所得的最大垂直平均流速来计算S-H参数,认为潮锋出现位置位于S-H参数值为2处,与实测结果较为一致,且认为正压模式比斜压模式更能准确模拟潮混合区。另外,分析观测数据发现,温度、盐度、密度锋终年存在。近岸处密度锋主要受盐度锋控制,而潮混合产生的盐度锋又容易被径流掩盖。风力较大时三种锋都易向水深更深处推进,潮混合区终年垂向混合较好。 相似文献
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深水蕴藏着丰富的油气资源,国内的油气勘探开发重点正在向海上转移。国外有相对成熟的深水钻井工艺,国内的深水钻井工艺研究刚刚起步,与之相配套的深水录井工艺在国内几乎还是空白。从HSE保障、油气显示发现及解释评价、优化钻井、钻井信息化建设等方面分析了国内深水钻井对录井的需求;从保障钻井安全、工程参数获取、岩屑采集、钻井液气体分析、资料的综合解释等方面阐述了深水钻井给录井带来的影响,并提出了对策,对深水录井的发展提出建议。 相似文献
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We studied the microbial communities collected from hydrate-bearing sediments on the North Slope of Alaska to determine how abiotic variables (e.g., grain size, hydrate presence, formation fluid gases) may correspond to the type and distribution of microbes in the sediments. The cores were acquired from sub-permafrost, Eocene (46-55 million year old) sediments in the BPXA-DOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test Well within which hydrates are believed to have formed 1.5 mya. Forty samples, eight of which originally contained hydrates, were acquired from depths of ca. 606-666 m below land surface. Five drilling fluid samples acquired from the same depth range were included in the analysis as a control for possible contamination by drilling fluid microbes during the drilling and handling of cores. DNA was extracted from 15 samples (typically <1 ng DNA/g sediment was recovered) and then amplified using polymerase chain reaction with primers specific for bacterial and archaeal 16S rDNA genes, which indicates the likelihood that microbes were present in all analyzed samples. Only bacterial DNA amplicons were detected. Terminal-restriction fragment length polymorphism (T-RFLP) was used to measure bacterial diversity in the respective samples. Non-metric multidimensional scaling (NMS) was used to determine the abiotic variables that may have influenced bacterial diversity. NMS analysis revealed that the microbial taxa present in the sediment were distinct from the taxa present in the drilling fluids suggesting that the sediments were not contaminated by the drilling fluids. Multi-response permutation procedures (MRPP) found no significant difference between three sample groups identified a priori as being from within a hydrate zone, outside of hydrate zone, or on the edge of a hydrate/non-hydrate zone according to downhole nuclear magnetic resonance spectroscopy logs. However, among the several other abiotic parameters that were evaluated mud gas methane concentration and variables related to hydrate presence (e.g., chloride concentration, salinity, and resistivity) appeared to define the arrangement of microbial community signatures in plots resulting from NMS analysis. Communities from hydrate and non-hydrate layers each contained unique taxa as determined by the T-RFLP assay. 相似文献
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苏北盆地阜宁组三段油藏属低中渗储层。在储层敏感性与损害机理研究基础上，通过对油田开发全过程的储层损害因素分析，认为钻井液和注入水是损害储层的两个主要因素。着重研究了保护阜三段油藏储层的钻井液技术，开发了保护储层的改性正电胶钻井液体系和屏蔽暂堵剂。现场应用表明：该钻井液体系能明显降低表皮系数，试验井油井的平均产量比非试验邻井增产三成以上，储层保护效果明显。 相似文献
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主要探讨了半潜钻井平台浮体结构由于受到海洋环境腐蚀作用后的时变极限强度问题。首先,总结各种关于腐蚀损伤的平均厚度缩减模型,选择较能反映实际腐蚀过程的数学模型来估量浮体的钢板厚度缩减。在此基础上进行一系列极限强度计算,根据计算结果给出浮体极限强度预报公式。最后研究不同纵向构件板厚折减对极限强度的影响,发现浮体角隅板的单位体积影响率最高,而占结构比例大的构件厚度折减也将使得强度大大削弱,这两类纵向构件需要予以重点腐蚀保护。 相似文献
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AbstractIn this article, the results of an experimental study on the effect of drilling fluid on concrete-soil/rock interface shear strength in the seawater drilling environment are presented. The series of direct shear tests using a purpose-designed shear box with seawater were performed considering different types of drilling fluid and base material, various normal stress levels at the interface, and filtration times. The results indicated that bentonite drilling fluid significantly decreased the concrete-soil/rock interface shear strength while a negligibly small effect was observed for polymer drilling fluid, confirming the findings from the previous studies. It was also observed that the degree of interface shear strength reduction when using bentonite drilling fluid varied with the type of base material as well as the level of normal stress at the interface. The results also confirmed that the groundwater chemistry does not alter governing mechanism of the drilling fluids and the concrete-soil/rock interface interaction and that significant benefit can also be expected when using polymer-based drilling fluid over bentonite in terms of the side resistance of a drilled shaft in seawater drilling environment as well. 相似文献
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Jonny Hesthammer Aristofanis Stefatos Mikhail Boulaenko Alexander Vereshagin Peter Gelting Torolf Wedberg Gregor Maxwell 《Marine and Petroleum Geology》2010
The use of the controlled source electromagnetic (CSEM) method as a risk reduction tool in marine hydrocarbon exploration is gaining increased acceptance in the oil industry. This is related to the ability to map resistivity contrasts in the sub-surface and thus aid the detection of hydrocarbons which are typically more resistive than surrounding rocks. Whereas acoustic (seismic) energy allows for mapping sub-surface structures that may contain hydrocarbons, electromagnetic (EM) energy can often say something about the fluids contained within the structures. Numerous successful CSEM case stories have been published over the past several years. However, there are also quite a few stories about “failure”-cases, although not well documented in the literature. Such “failure”-cases may reflect the lack of understanding of the CSEM technology and how CSEM data can act as a value driver. In order to understand this, it is necessary to handle uncertainties and decisions associated with the technology, These include geological uncertainties, noise models, survey designs, forward modelling parameters, inversion/migration parameters and pre-processing of real data. A proper handling of these uncertainties and decisions will aid in defining and constraining the chance of geologic success and geologic-success-case net present value for prospects prior to drilling wells. As such, the CSEM technology has a significant potential to increase exploration efficiency, if applied correctly. 相似文献