Study On The Characteristics Of Chang 7 Reservoir In Longdong Area Erdos Extension Basins

Ordos Basin is an overall settlement, migration of large polycyclic Depression cratonic basins. Late Triassic sedimentary basin research and development history shows that lake from the formation, development, heyday to atrophy, built sets, reservoir, cap combined to form a hydrocarbon accumulation of basic geological conditions. In the deposition process of evolution, 7 is the expansion stage basin’s largest lake, deep, wide area, a set of oil shale deposition characteristics of up to nearly 100 meters of source rocks, the Mesozoic continental source rock foundation. In the heyday of the development of Late Triassic continental lake in three, in the semi deep to deep lacustrine facies in the development of a large area of the member 7 of Yanchang Formation of organic rich high-quality hydrocarbon source rocks, the hydrocarbon source rocks are the best source rock in the basin, its appearance is black, the ignition of flammable, Erdos Triassic Basin extended chang 7 layer is the most important source rock in the basin are studied.Longdong area is located in the southwest of the basin, the basin is located in Chang 7 period at the height of the center of the basin, in the semi deep lake to deep lake sedimentary environment, early studies suggested that long mainly developed 7 small-scale turbidites, tight lithology, it is difficult to form an effective reservoir However, oil and gas exploration in recent years indicated that the Delta and Southwest Associated turbidite is also rich in oil and gas resources, the scale is considerable, especially with the exploration data and new geological information accumulation, development and application of lithologic reservoir exploration technology, 7 layer system has become important to succeed,But at present, 7 long sedimentary characteristics of sand body development and distribution, oil enrichment regularity and controlling factors of the lack of knowledge, especially for the sedimentary microfacies and reservoir microscopic pore structure is seldom involved, set the core content of physical layer of micro pore structure is oil and gas reservoir, because of the complexity of pore structure, research the pore structure of the reservoir is a comprehensive application of several technology development direction. In this paper, through the analysis of reservoir sand body distribution characteristics, diagenesis, pore structure and seepage characteristics.Sedimentary evolution, special and complex background, especially the lacustrine turbidite formation in Longdong area, the long 7 layer showed a series of special reservoir characteristics, for example: the tight reservoir, complex pore structure, fluid in the complex seepage and etc.Longdong area in Chang 7 layer preliminary exploration, development practice has proved that this kind of reservoir development is very difficult, the single well production is low, slow conduction zone energy reserves, more difficult. Therefore, development of Longdong area long 7 reservoir characteristic research, especially the research of micro pore structure reservoir control factors for clear relatively high quality reservoirs, the optimization of reservoir reconstruction, has the important guiding significance to establish high efficiency development technology countermeasure.