Abstract：

Conglomerate oil reservoirs have reserves exceeding 2 billion tonnes in China and are one of the important replacement fields for oil and gas energy in China. However, conglomerate reservoirs contain a large amount of gravel, which is very heterogeneous mechanically and has significant differences in crack propagation paths. It is difficult to achieve balanced distribution of fractures in fracturing, and it is difficult to effectively explain using existing theories of uniform rock crack propagation. Therefore, it is necessary to explore relevant theories and methods applicable to conglomerate. In response to the characteristics of conglomerate reservoirs and the difficulties in development engineering, this article explores the difficulties and countermeasures in conglomerate development from five aspects: rock characteristics, research methods, mechanical characteristics, fracture propagation and hydraulic fracturing technology. Based on this, a multi-scale analysis method was proposed for comprehensive mesoscale, conventional scale, large scale model, meter scale, and field scale, and the laboratory research results were applied to oilfield sites through scale upgrading; Clarifying the gravel, mixed base, and cementation surface is the key to controlling rock mechanical parameters and fracture patterns. It is necessary to establish a weak cementation surface model to improve the accuracy of mechanical parameter prediction; It has been clarified that there are two modes of conglomerate fracture propagation: through gravel and around gravel, with obvious process zone characteristics. A fracture propagation model suitable for conglomerate can be constructed based on the double K fracture criterion to predict the initiation and propagation parameters; The compressibility evaluation should be guided by the integration of geological engineering, integrating rock fabric characteristics and multi-scale mechanical parameters to establish, and optimize fracturing plans.

Key words：conglomerate; geology-engineering integration; multi scale; hydraulic fracturing; fracability

Received： 2024-01-09

Corresponding Authors：binghou@vip.163.com

Cite this article：王剑波, 侯冰, 滕卫卫, 李小迪, 刘见通, 梁宝兴, 张远凯, 魏云. 致密砾岩储层力学特征与水力裂缝扩展机理研究进展. 石油科学 通报, 2024, 09(06): 972-990 WANG Jianbo, HOU Bing, TENG Weiwei, LI Xiaodi, LIU Jiantong, LIANG Baoxing, ZHANG Yuankai, WEI Yun. Research progress on mechanical characteristics and hydraulic fracture propagation mechanisms of tight conglomerate reservoirs. Petroleum Science Bulletin, 2024, 09(06): 972-990.

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