摘要
印度河盆地是巴基斯坦最大的沉积盆地和油气能源基地,分为上、中、下3个次级盆地,与上、中印度河盆地相比,下印度河盆地特性鲜明,是该区近年来最主要的储量增长阵地。在参考BP巴基斯坦公司以往研究成果的基础上,主要基于联合能源集团有限公司在自己作业区内的地震、地球化学、钻井及油气田资料,开展下印度河盆地的地质特征、油气分布与聚集规律研究。研究认为:研究区主要生储盖组合为形成于大陆边缘盆地阶段的上侏罗统—下白垩统,由于地质环境差异,主要烃源岩(Sembar组页岩)是3个次级盆地中相当层位烃源岩成熟最晚的;储集层呈规律变化,底部(Sembar组砂岩)为斜坡扇和盆底扇组合,下部(底砂岩段)为三角洲前缘和潮汐类砂体组合,中部(中砂岩段)为稳定浅水三角洲前缘与滩坝相砂体组合,上部(上砂岩段)为动荡浅水三角洲前缘与滩坝相砂体组合。油气聚集主要受控于构造演化(在生储条件相当的情况下),形成3类富集区:反转构造带油气富集区、地堑带油气富集区和宽缓地垒带的构造—岩性油气藏富集区。以前陆盆地次级构造单元定位,油气主要发现于前缘隆起及其后的"斜坡区"。
The Indus Basin was subdivided into lower, middle, and upper sub-basins, which is the largest sedimentary basin and essential energy base of Pakistan.Compared to the Upper and Middle Indus Basin, Lower Indus Basin shows a distinct geological characteristic and it has been the main reserve increasing ar- ea in recent years. The paper, with reference to the previous research findings of BP Pakistan, is mainly based on the data from the seismic data, the geochemistry, the drilling results, the field development data and so on. Technical team carries out the petroleum geology, hydrocarbon distribution and accumulation fairway study in Lower Indus Basin.The major source-reservoir-seal combination was formed during Early Jurassic-Late Cretaceous of the continental margin stage.As a result of geological environmental difference, among these 3 sub-basins, Lower Indus Basin has the latest source rock mature stage on correlated forma- tion（Sembar shale） . Reservoir changes regularly,the bottom part（Sembar sandstone） is a combination of slope fan and basin floor fan;delta front and tidal sand constitute the lower part（Basal Sand）;the middle part（Middle Sand） is a set of stable shallow-water delta front and beach bar sand bodies complex;the upper part（Upper Sand） is comprised of turbulent shallow-water delta front and beach bar sand bodies.The accu- mulation of hydrocarbon is controlled by tectonic evolution（under the equivalent source and reservoir cir- cumstances）, formed 3 types of enrichment zones：Overturned structure belt, graben belt and broad gentle horst zone for structure-stratigraphic accumulation.Refer to the concept of foreland basin secondary tecton- ic unit, the fairway for most oil and gas accumulation in Lower Indus basin belongs to the frontal uplift belt and its behind slope zone.
出处
《天然气地球科学》
EI
CAS
CSCD
北大核心
2017年第12期1797-1809,共13页
Natural Gas Geoscience
关键词
地质特性
前陆层序
大陆边缘
三角洲
浊流
潮汐
油气聚集
Geological features
Foreland sequences
Continental margin
Delta
Turbidity current
Tidal deposition
Hydrocarbon accumulation
