综合应用测井和三维地震数据,对尼日尔三角洲盆地西部浅海沉积带Ariki油田的构造格架和地层层序进行了解释,并开展了断裂控藏分析。该油田主力储集层Agbada组内识别出5个最大洪泛面和5个层序界面,构造格架受控于伸展构造活动所形成的主断层、次级断层以及滚动背斜。研究区共发育7条断层,可划分为3个主断层和4个次级断层;在油田西翼,次级断层活动形成类似地堑和地垒的构造。通过断距分析,认为在1 800 ms以下,主断层断距加大,主断层作为油气运移通道;在1 800 ms以上,主断层断距变小,可以作为油气圈闭遮挡。研究区存在四面下倾的滚动背斜和次级断层控制的三面下倾闭合圈闭等多种远景构造圈闭,有利于提升石油区带的规模勘探潜力。图8表1参10
AHANEKU C V
,
OKORO A U
,
ODOH B I
,
ANOMNEZE D O
,
CHIMA K I
,
EJEKE C F
,
OKOLI I N
. 尼日利亚Ariki油田地层层序、构造格架与油气运聚[J]. 石油勘探与开发, 2016
, 43(1)
: 77
-83
.
DOI: 10.11698/PED.2016.01.09
The structural framework and stratigraphy of the Ariki Field in the Western Shallow Offshore Depobelt, Niger Delta Basin, Nigeria are interpreted using well logs and 3-D seismic data, and the control of rift on hydrocarbon accumulation is analyzed. Five maximum flooding surfaces and five sequence boundaries are identified in the major reservoir of Agbada Formation in the field; and the structural framework of the field is controlled by the major faults, minor faults and rollover anticline formed by extensional tectonic movement. There are a total of seven faults identified across the field, including 3 major faults and 4 minor faults. On the western flank of the field, graben and horst-like structures were created by the minor faults. Fault throw analysis shows that below 1800 ms, the major faults with fault throw increasing act as hydrocarbon migration pathways, while above 1800 ms, with fault throw decreasing, they act as seals of hydrocarbon traps. There are four-way dip rollover anticlines and 3-way downdip traps created by the minor faults, and other prospective traps in the study area, which have substantial oil exploration potential.
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