关键词: 河西务构造带, 油气成藏, 主控因素, 勘探方向

Abstract: Located in the eastern part of Langgu Depression with a high degree of exploration. Hexiwu Structure has a certain potential for resources and a background for exploration. A series of targets have been found through the efforts for 3D seismic interpretation, analysis of the whole structure, study of overall sedimentary sand body, simulation of the whole oil and gas reservoir, integrated assessment of the whole zone and belt and detailed research. The study indicates that this region saw development of three sets of main source rock formation, which are dark mudstone of Es3 and Es4 as well as mudstone of Carboniferous- Permian deposited under deep lake environment. The structure is relatively rich in oil and gas resources with development of three major sedimentary systems-fan delta, delta and river, providing eight sets of good reservoir-cap assemblages from buried hill to the Neocene System. Hexiwu Structure saw development of five types of structural, stratigraphic, lithological, compound and buried hill oil and gas reservoirs. The result of hydrocarbon accumulation model shows that oil and gas accumulations in Hexiwu Structure are mainly controlled by hydrocarbon sourcing faults, unfolding of Paleogene sand body and development degree of fractural reservoirs. The comprehensive study indicates that the future exploration orientation is the western part of Hexiwu area and buried hill.