Abstract: The sedimentary characteristics of the sublacustrine fan body and its petroleum geological significance are studied based on core, logging, logging and seismic data. It is found that the sublacustrine fan deposits in this area can be divided into three subfacies: inner fan, middle fan and outer fan, and five types of sedimentation, including main channel, braided channel and turbidite of inner fan. Cumulative microfacies. The lower part of the sublacustrine fan deposit in the Huodomoer structural belt is adjacent to the best source rock section of Nantun Formation. Oil and gas are injected into the sublacustrine fan sand body from the bottom and side, and are usually blocked by faults to form fault⁃lithologic reservoirs or directly blocked by surrounding mudstones to form lenticular lithologic reservoirs. The hydrocarbon accumulation is mainly controlled by reservoirs. Physical characteristics of layers. The experimental analysis shows that the reservoir capacity of different sedimentary microfacies is quite different. The braided channel microfacies of the middle fan is the most favorable reservoir facies type, followed by the main channel microfacies of the inner fan, which is the more favorable reservoir. Oil and gas exploration practice also confirms that high⁃yield wells are mostly located in braided channel microfacies of middle fan and have broad prospects for exploration.

Key words: Hodomoer structural belt, Nantun formation, Sublacustrine fan, Sedimentary characteristics, Geological significance of oil and gas

摘要： 综合岩芯、测井、录井、地震等资料，对霍多莫尔构造带湖底扇体的沉积特征及其油气地质意义进行了研究，发现本区湖底扇沉积共可划分为内扇、中扇、外扇三大类亚相以及内扇主沟道、中扇辫状沟道、外扇浊积岩等五类沉积微相。霍多莫尔构造带湖底扇沉积所在层系向下紧邻南屯组内最好的烃源岩层，油气从下方和侧面向湖底扇砂体内充注，通常受断层遮挡形成断层-岩性油气藏或直接被周围的泥岩封堵形成透镜体形式的岩性油气藏，油气成藏与否主要受控于储层的物性特征。实验分析表明，不同沉积微相的储集能力具有较大的差异，其中中扇辫状沟道微相是最有利的储集相带类型，内扇主沟道微相次之，为较有利储层。油气勘探实践同样证实，高产井多位于中扇辫状沟道微相内，勘探前景广阔。

关键词: 霍多莫尔构造带, 　南屯组, 　湖底扇, 　沉积特征, 　油气地质意义