长庆气田主力气层为马五１。通过观察大量岩心，从裂缝充填成分、碳氧同位素及其它地球化学特征着手，并结合地质、钻井、测试多种方法，对马五１储层裂缝类型、形成期次、成因类型划分以及裂缝形成的地质因素进行深入研究分析，总结出马五１储层裂缝类型及特征。马五１储层裂缝类型主要有四种，即垂直缝、斜交缝、水平缝及网状缝；马五１储层裂缝成因类型多，其中对储层渗流作用影响较大的主要有两大类，即构造缝和风化缝；据裂缝充填物碳氧同位素测定、包裹体光谱成分以及探针成分分析，马五１储层裂缝形成期主要有三期。第一期为加里东期，形成各类风化缝；第二期为燕山中期，是一次重要的构造破裂期，主要形成构造缝；第三期为燕山晚—喜山早期；风化缝的形成主要与风化岩溶作用形成地貌条件、岩层产状等因素有关；构造缝的形成与古应力场条件及岩石本身的力学属性有关 The main gas layer in Changqing Gas Field is Ma Wu 1. By observing a large number of cores, fracturing types, formation stages, types of genesis and formation of fractures in the Ma-51 reservoir are studied from fractures, carbon and oxygen isotopes and other geochemical characteristics in combination with geological, drilling and testing methods. The geological factors in-depth study and analysis, summed up the Ma 5 1 reservoir fracture types and characteristics. There are mainly four types of fractures in Ma-5 reservoir, namely vertical fractures, oblique fractures, horizontal fractures and reticular fractures. There are many types of fractures in MA51 reservoir, of which there are two main types that have a great influence on seepage of reservoirs According to the determination of carbon and oxygen isotopes of fracture fillings, the spectral composition of inclusions and the probe composition analysis, there are mainly three stages of fracture formation in Ma-51 reservoir. The first period is the Caledonian period, forming various weathering seams. The second stage is the mid-Yanshanian period, which is an important tectonic fracture period and mainly forms structural seams. The third period is late Yanshan-Early Himalayan formation and the formation of weathering seams Which is related to the formation of geomorphic conditions and the occurrence of rock formations caused by weathering karstification. The formation of structural joints is related to the conditions of paleotropical fields and the mechanical properties of rock itself