通过对川东北达县—宣汉区块毛坝场构造二叠系长兴组构造、断裂、储层沉积相、储层四性、 天然气组分、储量计算、气藏类型等特征的分析，认为二叠系长兴组构造落实、可靠，储层为生物礁。储层发育主要受沉积相、成岩作用、构造作用等因素控制。根据气体组分分析及储量计算，认为毛坝场构造二叠系长兴组为富含CH4、高含H2 S、低温、高压、超深层、中产、低丰度、中—小型气藏。

The characteristics of structure, fault, sedimentary facies, four properties, gas component, calculation of reserves and gas reservoir types of Permian Changxing Formation of Maobachang structure in Daxian-Xuanhan area in northeastern Sichuan are analyzed. It is believed that the reservoir of Permian Changxing Formation in Maobachang structure is organic reef. The reservoir is mainly controlled by sedimentary facies, diagenesis and tectonism. According to the gas component analysis and calculation of reserves, the gas reservoir is characterized by a medium-small gas reservoir with rich CH₄ , high component of CO₂ , low temperature, high pressure and low abundance.