Numerical prediction of MODUs drift during Hurricane Katrina

Severe hurricanes, such as Katrina, broke the mooring lines of a number of mobile offshore drilling units (MODU) deployed in the Gulf of Mexico and some of those MODUs went adrift. A drifting MODU may damage other critical elements of the offshore oil and gas infrastructure by colliding with floating or fixed production systems and transportation hubs, or by rupturing pipelines owing to their dragging anchors over the seabed. To avoid or mitigate the damage caused by a drifting MODU, it is desirable to understand the mechanics of the drift of a MODU under the impact of severe wind, wave and current and have the capability of predicting the trajectory of the drift. To explore the feasibility and accuracy of predicting the trajectory of a drifting MODU based on hindcast met-ocean conditions and limited knowledge of the condition of the drifting MODU, this study employed a simplified equation describing only the horizontal (surge, sway and yaw) motions of a MODU under the impact of steady wind, current and wave forces. The simplified hydrodynamic model neglects the first- and second-order oscillatory wave forces, unsteady wind forces (owing to wind gustiness), wave drift damping, and the effects of the body oscillation on the steady wind and current forces. It was assumed that the net effects of the oscillatory forces on the steady motion are insignificant. To verify the accuracy and feasibility of our simplified approach, the predicted drifting trajectories of two MODUs were compared with the corresponding measurements recorded by the global positioning system (GPS).     

Effective medium modeling to assess gas hydrate and free-gas evident from the velocity structure in the Makran accretionary prism, offshore Pakistan

Seismic properties of sediments are strongly influenced by pore fluids. Stiffness of unconsolidated marine sediment increases with the presence of gas hydrate and decreases with the presence of gas. A strong bottom-simulating reflector (BSR) observed on a seismic profile in the Makran accretionary prism, offshore Pakistan, indicates the presence of gas hydrate and free-gas across the BSR. Elastic properties of gas depend largely on pressure and temperature. We, therefore, first determine the elastic modulus of gas at pressure and temperature calculated at the BSR depth in the study region. The interval velocities derived from the seismic data are interpreted by the effective medium theory, which is a combination of self-consistent approximation and differential effective medium theories, together with a smoothing approximation, for assessment of gas hydrate and free-gas. The results show the saturations of gas hydrate and free-gas as 22 and 2.4% of pore space, respectively, across the BSR.     

Theoretical Model and Dynamic Analysis of Soft Yoke Mooring System

As a popular solution for mooring an FPSO （Floating Production, Storage and Offloading） permanently in shallow water, the soft yoke mooring system has been widely used in ocean oil production activities in the Bohai Bay of China. In order to simulate the interaction mechanism and conduct dynamic analysis of the soft yoke mooring system, a theoretical model with basic dynamic equations is established. A numerical iteration algorithm based on error estimation is developed to solve the equations and calculate the dynanfic response of the mooring system due to FPSO motions. Validation is conducted by wave basin experimentation. It is shown that the numerical simulation takes only a few iteration times and the final errors are small. Furthermore, the calculated results of both the static and dynamic responses agree well with those ones obtained by the model test. It indicates that the efficiency, the precision, the reliability and the validity of the developed numerical algorithm and program are rather good. It is proposed to develop a real-time monitoring system to further monitor the dynamic performance of the FPSO with a soft yoke mooring system under various real sea environments.     

4种酞酸酯在龙须菜-篮子鱼食物链中的积累放大研究

在模拟受控条件下,利用气相色谱方法研究分析了4种酞酸酯类化合物在龙须菜(Gracilaria lemane-iformis)-篮子鱼(Siganus oramin)食物链中的积累、分布和放大状况。结果表明,4种酞酸酯在龙须菜组织内的积累表现为:邻苯二甲酸二异辛酯(DEHP)>邻苯二甲酸二丁酯(DBP)>邻苯二甲酸二乙酯(DEP)>邻苯二甲酸二甲酯(DMP)。侧链最长的DEHP在龙须菜藻体内的含量随暴露时间的延长呈增加的趋势,30 d体内积累量可达2.35 mg/kg(鲜质量);侧链最短的DMP在龙须菜藻体内的质量比随时间变化差异不显著,约为0.05 mg/kg;在30 d的暴露中,4种酞酸酯DMP,DEP,DBP和DEHP在篮子鱼体内总质量比分别为0.08,0.41,1.72,3.11 mg/kg。其中DBP和DEHP在鱼内脏组织中有较高的积累和分布,分别为1.14 mg/kg和1.83 mg/kg,其次为鱼残体组织,肌肉组织中含量最低。DEHP和DBP在龙须菜和篮子鱼体不同组织中均有一定程度的富集(生物富集系数FBC均大于1)。其中DEHP和DBP在内脏组织中的FBC值分别高达9.16和5.68,在龙须菜-篮子鱼这个简单食物链传递中DEHP和DBP在篮子鱼内脏组织中存在放大现象。     

矿产资源开发整合与区域矿业经济发展浅析——以潍坊市滨海新区卤水资源为例

对矿产资源开发进行整合是集中解决矿山布局不合理,实现规模化、集约化开发的重要手段,是调整矿业结构、促进矿业经济增长方式转变的有效途径。潍坊市滨海新区通过对卤水资源进行整合,初步实现了卤水资源的规模化开采和集约化经营,并在培育矿业龙头企业的基础上,注重矿业产业链的延伸和完整化,构建生态海洋化工产业集群,从而形成比较优势和核心竞争力,促进区域矿业经济发展。     

浅层物探技术在近海灾害地质与工程地质调查中的应用

随着海洋资源的开发与滨岸工程的建设,越来越多地遇到海洋地质灾害的影响与危害。为了避免并降低海洋地质灾害的影响程度,应开展海洋灾害地质与工程地质调查。二十多年来的实践经验表明,若采用以高分辨率地震为主,配合浅地层剖面、旁侧声纳、测深及磁力测量等综合浅层物探技术,对于了解海洋地质灾害因素与海底浅部工程地质特性等方面都能取得良好的效果,这是一种既经济又较快速地提供成果资料的好方法。     

用于锦州9-3油田驱油技术的聚合物评价

聚合物驱油技术适用于非均质的中质和较重质油藏,与其他提高采收率技术比较起来相对简单,更符合海上油田安全环保要求。根据渤海锦州9-3油田油藏特性和聚合物结构性能,结合海上平台特点,研制出具有高效增黏、较好的抗剪切性、良好流动性和驱油效果的高抗盐聚合物3640D。该聚合物首次用于海上油田单井聚合物驱先导试验见到了显著的增油降水效果,正在进行中的井组聚合物驱试验也已初步显示出增产效果,表明聚合物3640D作为锦州9-3油田的驱油剂在技术上是可行的,在海上类似油田的聚合物驱技术中具有广阔的应用前景。     

海上高温低渗油田酸化技术应用研究

针对渤中34油田油藏孔隙度渗透率比较低、温度比较高（大于120℃）的特点,结合储层伤害原因分析,根据室内试验结果,采用多氢酸体系对渤中34油田的油井进行酸化增产作业。通过对渤中34油田5口井（均为新井,完井后基本不出液）的酸化施工,酸化成功率达到100％,酸化后各井均达到甚至超过配产要求,这表明多氢酸体系对于高温低渗砂岩地层,能够有效地解除钻完井过程中造成的污染。与常规酸液体系相比,多氢酸体系具有明显的优势且效果明显,对于类似海上油田酸化有较强的借鉴意义。     

Sequence analysis and quantitative detection of Norwalk-like viruses in cultured oysters of China

We isolated 4 Norwalk-like viruses (NLVs) contaminated oysters from 33 Chinese oysters collected from local commer-cial sources of Shandong Province. After amplification of the RNA-dependent RNA polymerase (RdRp) region of NLVs genomes with RT-PCR, the open reading frame 1 (ORF1) of the RdRp was sequenced and subjected to multiple-sequence alignment. The re-suits showed that NLVs in the four isolates belong to genogroup Ⅱ. The sequence comparison showed that the similarity between four Chinese oyster isolates were higher than 99.0%, which indicated that NLVs prevalent in close areas have high homogeneity in genome sequences. In addition, the most conserved sequences between diverse NLVs were used to design primers and TaqMan probes, then the real-time quantitative PCR assay was performed. According to the standard curve of GII NLVs, the original amounts (copies) of NLVs in positive patient's fecal isolate, positive Japanese oyster isolate, and the Chinese oyster isolate were 8.9×108, 1.25×108 and 4.7×101 respectively. The detecting limit of NLVs was 1×101 copies. This study will be helpful for routine diagnosis of NLVs pathogens in foods and thus for avoiding food poisoning in the future.     

苹果手机零部件全球价值链的价值分配与中国角色演变

产品内分工已成为支配当代企业分工与产品生产的重要模式。研究智能手机生产网络价值分配格局,对辨析中国大陆企业在移动通讯产业价值链中所处地位与演进具有重要意义。论文利用2012—2017年苹果公司供应商数据,以其零部件价值含量与技术要求为测度标准,分析了苹果手机零部件全球价值链的分配特征以及中国大陆企业在其中的地位变化。发现：高价值环节的供应商主要以美国、日本、韩国为主,而中低价值环节则以中国台湾、日本和中国大陆供应商为主,且中国大陆与中国台湾在中间环节占据重要地位。处于价值链高端的供应商分支数量在中国大陆和美国缩减明显,日本、韩国较为稳定,中国台湾增加明显。在价值链的中低端环节,供应商分支趋向中国大陆集中。印度、巴西以及越南等地成为新的中低端价值环节转移承接地。近年来,中国大陆在苹果手机价值链的高端环节得到了提升,长三角、珠三角、京津冀、成渝、中原地区等地逐渐形成了苹果供应商分支的集聚区域,呈现出零部件生产的区域分工特征。长三角(上海-苏州为核心)与珠三角(深圳-东莞为核心),承接了价值链多个生产环节,是中国大陆嵌入苹果手机生产网络的主要阵地。成渝地区既承接了芯片类企业布局,也承接了价值链低端的组装代工和包装服务环节,呈现出在价值链两端双向承接的特征。环渤海、福建及湖南等地主要承接苹果手机价值链的中间环节,而中原地区主要以苹果手机组装与包装服务为主,承接价值链的低端环节。最后,论文从创新驱动、政府作用与外资等方面探讨了影响中国大陆地位提升的因素。