黄河水下三角洲海底管线差异沉降的安全性分析

针对胜利油田埕岛海域海床土体强度的非均匀性和可能引起的海底管线差异沉降破坏,提出1种海底管线差异沉降安全性分析方法.具体介绍差异沉降产生的原因,通过分析管线的受力状态,建立管线因差异沉降引起的附加应力的表达式.针对黄河水下三角洲埕岛油田常见的3种规格管线,建立不同土质条件下的管线附加应力表格,方便工程师查询.考虑附加应力和流体对管线的应力,与管线材料的允许应力比较,可以判断管线的安全性.     

Modeling of suspended sediment transport with waveinduced longshore current in Huanghe (Yellow) River Delta

A three-dimensional suspended sediment model(SED)developed by the present authors is coupled with the combinatorial model of COHERENS(Luyten et al.,1999) (the three-dimensional coupled hydrodynamical-ecological model for Regional and Shelf Seas) and SWAN(Holthuijsen et al.,2004) (the third generation wave model).SWAN is regarded as a subroutine of COHERENS and gets time-and space-varying current velocity and surface elevation from COHERENS.COHERENS gets time-and space-varying wave relevant parameters provided by SWAN.Effects of wave on current are applied in bottom shear stress,wave-induced depth-dependent radiation stress and surface drag coefficient calculation.At the same time,the damping function of suspended sediment on turbulence is introduced into COHERENS.So the sediment model SED has feed back on circulation model COHERENS.The SED obtains current as sociated parameters from COHERENS.Then a couple dhydrodynamic-sediment model COHERENS-SED being able to account for interaction between wave and current is obtained.COHERENS-SED is adopted to simulate three-dimensional suspended sediment transport in the Huanghe River delta.In terms of simulation results,there is obvious diffierence between top and bottom layer of wave-induced longshore current.The values of time series of sediment concentration gotten by COHERENS-SED have,generally,an accepted agreement extent with measurement.Significant wave heights and wave periods obtained by COHERENS-SED show that wave simulation case with current’s effect can give better agreement extent with measurement than case without current’s effect.In the meantime,suspended sediment concentration distributing rule obtained by COHERENS-SED is similar to former researches and measurement.     

基于测井约束的储层参数预测——以惠民凹陷临北地区为例

临北地区储层自东向西减薄尖灭,横向变化大,由于断裂复杂,地震反射特征紊乱,采用常规的储层预测方法很难确定砂体的尖灭点,划分有利储层发育区。针对这一问题,进行了基于测井约束的储层参数预测方法研究：①采用正演模拟技术,确定临北地区砂体地震反射特征;②利用地质统计学方法进行储层参数集总;③在提取多种地震属性的基础上,通过地震属性优化,选取累加正振幅、最大能量、平均波峰振幅等地震属性参数;④根据测并储层参数与地震属性拟合关系,进行储层参数平面外推和预测,利用井点处的储层参数值对预测结果进行约束。利用以上方法对临北地区基山三角洲五砂组进行了储层预测,实现了地震属性到储层岩石物性参数的转换,预测的有利储层分布区与钻井解释结果相关程度较高,符合该区的地质规律,在实际应用中取得了较好的效果。     

大量采沙对东江下游及东江三角洲河床地形和潮汐动力的影响

The sand dredging and its impacts on riverbed evolution and tidal dynamic change in the lower reaches and delta of the Dongjiang River are examined in this paper. The large amount of sand, totally 3.32 billion m^3 from 1980 to 2002, was mined from the riverbeds of the lower reaches and delta of the Dongjiang River. Increasing of the channel capacity, lowering of the average riverbed elevation, deepening of the water depth and decreasing of the longitudinal riverbed gradient are the main effects on the riverbed evolution brought by the large amount of sand dredging. Under the strong sand dredging and associated significant riverbed deformation, the notable changes of the tidal dynamic in the lower reaches and delta of the Dongjiang River occurred, including： （1）in the upper reaches of the Dongjiang River delta and lower reaches of the Dongjiang River, tidal level dropped apparently, tidal range widened, flood tidal duration became longer, amplitudes for major tidal components became bigger and tidal dynamics intensified; （2） tidal wave spread faster; and （3） the limits of the tidal level, tidal current and salt water moved upstream.     

辽东湾J油田东三段上部沉积微相及其对油气分布的影响

J油田东三段上部主要为三角洲前缘和前三角洲沉积亚相体系,发育河口坝、水下分流河道、分流间湾等微相。其中河口坝、水下分流河道砂体储集性能较好,分流间湾较差。本区段沉积亚相和沉积微相的类型和展布特征决定了储层砂体的性质和展布,进而控制和影响油气的储集和分布。储层评价结果表明E3d^3-Ⅰ-2最好,E3d^3-Ⅰ-3次之,E3d^3-Ⅰ-1较差。     

辽河三角洲湿地资源景观特征评价及生态旅游开发

生态旅游概念提出以来,全球生态旅游在理论和实践2个方面都得到了很大发展,成为现在主要的旅游活动形式之一.辽河三角洲是我国七大江河三角洲之一,拥有丰富的湿地资源,非常适合进行生态旅游的开发.文章在分析辽河三角洲湿地资源景观特征的基础上,结合该地区旅游开发存在的问题,对其开展湿地生态旅游的前景作了分析,提出了开展湿地生态旅游的对策.     

黄河三角洲地区平原水库规模论证

黄河三角洲可垦荒地和滩涂面积大 ,开发条件优越 ,地下石油丰富 ,黄河口流路横贯三角洲 ,是三角洲地区开发建设的宝贵水源。黄河三角洲地区平原水库的建设规模是一项重要的工程规划指标 ,平原水库规模的大小 ,对三角洲地区国民经济和社会发展将具有重大的影响 ,因此必须从来水、需水以及可供水量等多方面考虑 ,综合分析和确定。通过方案计算和比较分析 ,黄河三角洲地区平原水库库容规模为 6641 0× 1 0 4 m3。     

黄河口水下三角洲及其邻近水域线虫群落结构的比较研究

采用多元统计分析法，对黄河口水下三角洲及其邻近渤海莱洲湾和渤海中部的线虫群落结构进行了比较研究，结果表明，与10年前相比，线虫群落的种类组成有了显著的变化，渤海中部的非选择性沉积食性者（1B型）增加了1倍，莱洲湾则增加了5倍，表明该海域有机碎屑沉降量的显著增加，线虫群落在物种，属和科的水平上所作的多元统计图形比较表明，在物种和属水平上的图形无显著差异，这说明，这线虫而言，鉴定到属的样品分析，减少了鉴定到种的分类负提，能满足实际的工作需要。     

现代黄河水下三角洲粉土的临界水力坡降探讨

通过室内试验，测定不同密实度粉土的临界水力坡降。由试验结果可以看出，粉土的临界水力坡降与一般砂土有着较大差异，一般耗生土临界水力坡降icr＝（ρ-ρw）/ρw，变化范围在0.8-1.5之产，而现代黄河水下三角洲粉土的临界水力坡降为9.5-16.5。同时对土体进行受力分析，考虑颗粒间的凝聚力，对以上结果产生的机理,工找出临界水力坡降与其物理性质指标之间的关系。     

海平面上升对长江三角洲附近沿海潮滩和湿地的影响

于１９８８－１９９１年，对长江三角洲附近沿海潮滩和湿地进行较全面的调查，利用高程－面积法、沉积速率法，并引进未来冲淤趋势参数，对全区１４个典型潮滩断面进行海平面上升影响的估算。结果表明，当海平面上升０．５ｍ和１．０ｍ时，全区潮滩面积分别比１９９０年的减少９．２％和１６．７％；湿地面积减少２０％和２８％，并发生高级类型向低级类型的逆向演替。各岸段损失率相差悬殊，以侵岸段较大，淤涨岸段将减缓淤涨，甚至