主动大陆边缘海沟-斜坡盆地沉积体系分析——以缅甸若开海岸盆地某工区为例

本文以国内少见的发育在主动大陆边缘的特殊盆地类型海沟-斜坡盆地作为研究对象,通过建立井震结合的不同沉积体系的地质-地球物理识别模板,用二维地震资料对研究区目的层的沉积体系进行了解析。结果显示,研究区发育窄的滨浅海、小规模的三角洲、浊积扇、下切谷、半深海陆坡和半深海平原等沉积体系。滨浅海、三角洲和浊积扇沉积体系发育的砂体是主要的储集体。海沟-斜坡盆地的规模较小,以生气为主,可能形成中小型断块油气藏。

云南中甸五村-移山晚三叠世沉积及盆地特征

五村 移山地区晚三叠世地层发育齐全,并在中咱地块边缘至甘孜 理塘结合带之间构成一个较为完整的沉积盆地。中甸、格咱和弥里淌三条平行控制性断裂将盆地由西向东依次横向分割成中咱微大陆五村台地边缘三角洲、哈工弧后断陷盆地、属都火山复理石盆地和尼汝弧前斜坡(盆地)。在上述4种构造 相区中沉积了各具特色的沉积物,具有不同基本层序结构、不同生物组合及沉积相特征。显示盆地经历下降 抬升 下降 抬升两个周期性演化过程。

下扬子区寒武纪斜坡－盆地相沉积的成岩作用及储集类型

下扬子地区寒武系的白云石化作用、埋藏溶蚀作用及差异压实作用，是形成有利储集空间的重要成岩作用，形成裂缝－孔隙型硅质岩、微晶灰（白云）岩、裂缝型泥岩、微裂缝－缝合线型泥质灰岩和碎屑流砾屑灰岩、浊积岩等多种储集空间。

灾变事件地层斜坡滑塌(带)堆积的特征——以滇西保山地区上三叠统南梳坝组为例

保山地块保山地区三叠系上统南梳坝组研究程度较差,以往的资料多侧重于岩石地层、生物地层的研究,沉积环境资料甚少。通过1∶5万保山幅等8幅区域地质调查,在南梳坝组中发现了灰岩滑塌岩块、下超面、饥饿沉积、水道砾岩、粒序层理、复理石韵律及槽模、沟模等一系列非常重要的沉积相资料,认为其沉积环境为斜坡-盆地环境,总体为一套浊积岩,其中的同沉积"褶皱"、同沉积断层、大量的滑塌面、各种类型的滑塌褶皱组成了3条较大规模的滑塌带,是斜坡环境的沉积物在地震作用触发下形成的,剖面结构"不合理",明显具有灾变事件地层的特征。灰岩滑塌岩块有极浓的油气味,显示出生储存油气的良好环境。因此,重塑三叠系上统南梳坝组的古地理环境,不仅对发展沉积学、地层学有重要意义,而且对于寻找烃源岩也有重要的现实意义。

Sequence boundaries and regularities in the oil-gas distribution of the low swelling slope belt in the continental rift basin

Where are the zones more enriched in sand deposits in the down slope and deep depression of the low swelling slope belt? Are there any screening conditions for oil and gas there? These are the chief geological problems to be solved during exploration of a region. Taking the Paleogene system developed along the east slope belt of Chengdao as an example the concepts of sequence stratigraphy and sedimentary sequenc are applied. A new research method likened to a way ''to get a melon by following the vine'' is proposed to determine the direction for exploring within un-drilled or less-drilled areas. This is the process: ''the characteristics of the sequence boundary ? the forming mechanism of the stratigraphic sequence ? the conditions of oil and gas accumulation ? the distribution zones of oil and gas''. The relationship between the dynamic mechanism of stratigraphic sequence and the forming conditions for oil and gas accumulation establishes that the tectonic disturbance of the slope belt has significant responses as denudation and deposition. Above the stratigraphic sequence boundary there are large scale sand bodies of the low stand system tract (LST) that have developed in the low swelling slope belt and its deep depression. Below the sequence boundary there are the remaining sand bodies of the high stand system tract (HST). On the slope there is a convergence of mudstone layers of the extended system tract (EST) with the mudstone of the underlying strata, which constitutes the screening conditions for the reservoir of the down slope and deep depression. The distribution regularities in preferred sand bodies on the surface of the sequence boundary, and in the system tract, indicate the ordering of oil-gas deposits. From the higher stand down to the depth of the slope there are, in order, areas where exploration was unfavorable, major areas of stratigraphic overlap of oil-gas reservoirs, unconformity screened oil-gas reservoirs, and, finally, sandstone lens oil-gas reservoirs. The low swelling slope belt of Chengdao was tectonically active, which is typical for a continental rift basin. The methodology and results of the present paper are significant for the theory and practice of predicting subtle reservoir and selecting strategic areas for exploration.

贵州东南部下江群内波、内潮汐沉积的发现及其地质意义

广泛出露于贵州东南部及其毗邻地区的下江群,为一套巨厚的,以浊流沉积为主、伴有滑塌-滑移沉积和水道沉积的复理石建造。其主体部分普遍发育波痕、交错层理、脉状层理、透镜状层理等牵引流成因的特殊沉积构造。通过对这些特殊沉积构造进行系统观察和统计分析,结合伴生的已经证实的沉积类型,本文提出该区域内下江群中存在内波、内潮汐沉积,并对内波、内潮汐沉积特征进行描述。为合理解释以重力流沉积为主体的沉积体系中,牵引流沉积成因的沉积构造提供了一种新思路,为下江群沉积环境分析、新元古代南华裂谷盆地演化分析提供了新的证据。