埕岛油田及附近地区的水位

在渤海内,M2分潮有两个无潮点,一个在秦皇岛东面,另一个位于渤海湾至莱州湾之间。此外,渤海海峡附近还有一个K1分潮的无潮点。埕岛油田位于M2分潮无潮点和K1分潮波的腹部附近。整个石油开发区半日潮差均较小,其中以东南部最小,西北部有明显增加。全日潮差由东北向西南增加,变化幅度较小。在一般天气条件下,海面高度主要决定于潮汐,潮差不大,但在台风影响下,可能引起异常的增水,寒潮可以引起大的减水或增水。国内不少单位在黄河口做过潮汐观测,但资料甚少。埕岛油田位于黄河口的西北部,海上水位资料十分缺乏。我们利用12井位和20井位进行了4个月的水位观测,使用Aanderaa水位计,取样间隔为15min。岸边站(3站)是在岸边打桩,使用滚筒式水位计,获得了一年的水位观测资料,这些资料十分宝贵。本文详细地分析了该区域的水位特征,并给出施工设计需要的各个参数。

SEA LEVELS IN CHENGDAO OFFSHORE OIL FIELD AND ADJACENT AREA

A tidal level measurement project was carried out to estimate the design criteria for enginnering applications in the Chengdao Oil Field located northwest of the Yellow River estuary. Sea level was measured at a coastal station for a period of more than one year winter excluded because of icing. In the offshore area, tidal measurements were carried out at 8 stations: at one station for 2 months, at another 3 stations for 1 month, and at the remaining 4 stations for 2 days. The tidal records from offshore stations were analysed using regular methods. The tidal record at a coastal station was often interrupted during low water period. To extract tidai harmonics from these interrupted data, data gaps were filled artificially before conducting tidal analysis to obtain the harmonics, used to predict the sea level for the poriod of the gaps. Then the predicted sea level heights were used to replace the artificially given heights and a new analysis was made. The same procedure was repeated several times until the harmonics did not change. To confirm the validity of this approach, we used the tidal retcord of the longest offshore station and discarded the low water part data. The remaining data were analysed using the above approach. The obtained tidal harmonics differed only slightly (within 0.6cm in amplitude and 2° in phase lag) from those obtained by using original complete data. Analysis of the sea level records, yielded the distribution of the sea level for use as design criteria for engineering applications in the Chengdao Oil Field.