川东北元坝地区陆相储层天然裂缝发育特征及分布模式

evelopment characteristics and distribution patterns of natural fractures of continental reservoir in Yuanba area, northeastern Sichuan Basin

尚墨翰,赵向原,胡向阳,肖开华,刘国萍

中国石化石油勘探开发研究院，北京 100083 中国石化石油勘探开发研究院博士后工作站，北京 100083

川东北元坝地区陆相储层中发育多类天然裂缝且主控因素复杂。文中利用岩心、薄片及成像测井等资料对天然裂缝成因类型及发育特征进行了描述，并对控制裂缝发育的主要地质因素进行了分析，最终总结出研究区陆相储层天然裂缝分布模式。元坝地区陆相储层主要发育构造缝，具有多期发育的特征，且不同层段裂缝发育特征差异较大，主要受岩性、层厚及构造应力等因素控制。该区裂缝的主要形成时期为燕山中晚期和喜山晚期，先后在NW，NE这2个方向的应力影响下相互切穿、限制，最终形成复杂的裂缝系统，有利于改善储层物性，提升气井产能。

Many types of natural fractures with complex major controlling factors exist in the continental reservoir in Yuanba area, northeastern Sichuan. Data from core, thin section and image log were used to describe the genetic types and development characteristics of the natural fractures, and the main controlling factors of fracture development were analyzed. The natural fractures distribution pattern of continental reservoir in the study area were finally summarized. Tectonic fracture is the predominant fracture type of the continental reservoirs in Yuanba area, which have the characteristics of multi-stage development.The fracture characteristics vary greatly in different members, which are controlled by lithology, thickness of layers, and tectonic stress. The fractures in the study area were mainly formed during Middle to Late Yanshanian period and Late Himalayan period. Under the influence of main stresses in NW and NE directions successively, the fractures cut and restrict mutually, resulting in complex fracture systems which are favorable for the improvement of reservoir physical properties and high production rates of gas wells.

10.6056/dkyqt202201002