莺歌海盆地中新统轴向重力流沉积特征及勘探潜力

轴向重力流沉积是一种重要的深水储层,其形成的岩性油气藏也是目前莺歌海盆地重点勘探领域。通过钻井、测井、地震和区域地质等资料的综合研究,分析莺歌海盆地中新统轴向重力流沉积特征和演化规律,探讨轴向重力流岩性油气藏的成藏条件和控制因素。结果表明,中新统储层为重力流沉积成因的厚层细砂岩,主水道和朵叶复合体是重力流沉积有利的沉积微相;中新世海南物源供给充足、断裂坡折带发育以及盆地轴向负向地形是该区形成轴向重力流沉积的宏观地质条件,在中新世各个时期形成了一系列沿盆地轴向分布、具有前积反射结构特征的轴向重力流沉积。研究区中新统轴向重力流储层厚度大、沉积规模广、临近烃源岩、构造脊微裂隙发育、圈闭保存好,具备优越的岩性油气藏成藏条件,是盆地下一步勘探的重要领域。     

汾河水库流域人工增雨可行性研究

本文通过对汾河流域40a气象、水文资料的分析,结合现阶段人工增雨技术的研究,以增加水库蓄水量为目的,设计科学可行的人工增雨方案,并对可能的投入和预期产生的效益进行分析研究,为通过人工增雨增加水库蓄水量提供科学依据。     

Gravity Anomaly and Tectonics in the Northern Part of the North Fiji Basin - Preliminary Result of the 1994 NOFI Cruise under the NEW STARMER Programme

A surface ship gravity survey was carried out in the northern part of the North Fiji Basin during the NOFI cruise by the R/V l'Atalante in August-September, 1994. The two ridges inside the study area, the South Pandora Ridge and the Tripartite Ridge, present different structures and states of isostatic equilibrium in terms of gravity anomaly and its tectonic implications. The former is supported by a restoring force of an imaginary elastic plate in the crust and the latter by the Airy type isostasy. These characteristics can be derived from the difference in magmatic activity, as influenced by the difference in lithospheric structure. The latter is characterised by greater active magmatism and hydrothermalism underneath the ridge than the former. Such a difference in the magmatic activity and the horizontal scale of the shallow subsurface structure is derived from the difference in the stiffness or viscosity of the lithosphere beneath the two ridges.     

Surface circulation of the Levantine Basin: Comparison of model results with observations

The eastern Mediterranean (Levantine Basin) hydrography and circulation are investigated by comparing the results of a high-resolution primitive equation model with observations. After a 10-year integration, the model is able to reproduce the major water masses and the circulation patterns of the eastern Mediterranean. Comparisons with the POEM hydrographical observations show good agreement. The vertical distribution of the water masses matches that of the observations quite well in terms of monthly mean. The model surface circulation is in agreement with circulation schemes derived from recent observations. Some well-known mesoscale features of the upper thermocline circulation are also realistically reproduced. In agreement with satellite observations, the model shows that high-energy mesoscale eddies dominate the upper thermocline circulation in the southern and the central parts of the Levantine Basin. Most of the Atlantic Water follows the north African coast and forms a strong coastal jet near the Libyan coast rather than forming the Mid-Mediterranean Jet described by several authors. The sub-basin circulation shows a strong seasonal signal. A strong and stable current flows along the isobaths in winter, becoming weaker and with more meanders in summer. The mesoscale eddies throughout the whole basin are more energetic in summer than in winter.     

莺歌海盆地莺东斜坡带隐蔽油气藏类型及成藏主控因素

莺东斜坡带具有“两脊一洼”分段式展布之特殊区域地质构造格局,且自北而南“两脊一洼”三段式分布具有明显不同的构造及断裂活动特征与油气运聚规律,故不同区域区带隐蔽油气藏类型及成藏主控因素差异明显,其中,北段(即北延伸脊)成藏主控因素主要取决于烃源及油气运聚输导系统;中段(一洼即岭头断阶区)成藏主控因素则受控于烃源与岩性圈闭的有效性;南段(南延伸脊)成藏主控因素主要取决于地层岩性复合圈闭的有效性。根据不同类型隐蔽油气藏的成藏主控因素及分布规律,即可采取不同的研究方法及勘探技术对策,以期获得油气勘探的突破。     

长江河流入海泥沙通量的探讨

由于目前水文站在精确测量河流泥沙的方法上还存在缺陷,使用的方法还无法抓住‘沙峰’,故有理由提出过去在计算长江入海泥沙通量上总体是偏低的。依据水沙关系模型,对过去近40年来大通水文站提供的泥沙实测值和公布值做了计算,并在此基础上作了修正。结果表明,除了20世纪50年代模拟值略偏低外,60年代可达到约5~9亿t,70-80年代有所回落,在5~6.4亿t之间,这与20世纪50年代上游植被保存较好,而60年代则破坏较大,70-80年代又有所改善的背景基本一致。     

北黄海盆地北缘断裂带及其特征

根据最新调查获得的北黄海盆地海洋重力、海洋与航空磁力和多道地震资料,结合以往周边地区的资料,编制了北黄海空间重力异常图、布格重力异常图、磁力异常图。在重磁基础图件的基础上,通过解析延拓、任意方向导数计算、离散小波变换等处理,结合地震和地质资料,对北黄海北缘断裂带进行了综合分析。确定了北黄海北缘断裂带的存在,并对该断裂带的延伸长度、切割深度和性质进行了分析,指出北黄海北缘断裂带是辽东隆起与北黄海盆地的界线,断裂带两侧具有明显不同的地球物理场特征;而且断裂带具有多期活动的特点,对北黄海盆地的形成演化具有重要的控制作用。     

迈陈凹陷构造特征与油气勘探方向分析

迈陈凹陷位于北部湾盆地南部坳陷,是北部湾盆地的一个三级构造单元。从迈陈凹陷石油地质条件与各构造单元特征入手,详细讨论了迈陈凹陷断裂演化特征以及构造样式和构造带展布。在此基础上分析了迈陈凹陷油气成藏的主控因素和有利区带、层系。指出了迈陈凹陷可分为四个次级洼陷,其中东1洼流二段烃源岩发育情况最好,其斜坡带发育有大量的构造圈闭,与迈陈凹陷成藏匹配关系良好,是迈陈凹陷下一步勘探的主要方向。     

地形、气候与湖面波动对浅水三角洲沉积环境的控制作用——以松辽盆地北部东区葡萄花油层为例

松辽盆地北部东区葡萄花油层沉积时期,基底整体一致下降,气候干旱,地形平缓,河流入湖发育浅水三角洲。三角洲平原上的分流河道通过填积和湖面的频繁波动向湖泊中心方向长距离推进,在三角洲前缘的浅水区发育很有特色的水下分流河道,发育了宽展的三角洲前缘相沉积。在平面上,三角洲平原与宽展的三角洲前缘、前三角洲平缓相接,不存在Gilbert型三角洲模式的顶积层、前积层、底积层三褶结构。