Experimental study on spontaneous imbibition characteristics of tight rocks

Advances in Geo-Energy Research

article

Linhu Gao¹  Zhengming Yang²  Yue Shi³ 

[1] Hubei Subsurface Multi-scale Imaging Key Laboratory, Institute of Geophysics and Geomatics, China University of Geosciences;Department of Porous Flow & Fluid Mechanics, Research Institute of Petroleum Exploration & Development, PetroChina Company Limited;Department of Civil and Environmental Engineering, School of Mining and Petroleum Engineering, University of Alberta

关键词: Tight rocks;    spontaneous imbibition;    capillary pressure;   

DOI  :  10.26804/ager.2018.03.07

来源: Yandy Scientific Press

【 摘 要 】

In the exploitation of tight oil and gas reservoirs, multi-stage hydraulic fracturing technology is mainly used and a complex system of fractures and matrix is formed after fracturing. In the process of field production, it is reported that longer shut-in time results in good oil and gas production rate. The reason of this phenomenon is considered as the spontaneous imbibition of oil and gas driven by capillary force in reservoirs. Spontaneous imbibition is an important recovery mechanism in low permeability and tight reservoirs. The pore structure of tight rocks is very complex and the pore connectivity is poor. It is of great significance to study the imbibition mechanism of tight porous rocks. Through the combination of spontaneous imbibition experiments, this work studies the influencing factors and reveals the mechanism of the gas/oil recovery from tight reservoirs. The spontaneous imbibition experiments were carried on the gas/water system and the oil/water system. The swelling clay minerals in shales will enhance the imbibition. Cores with high permeability have small recovery, which may be due to the low capillary force in tight cores. Fractures can promote the imbibition volume of tight cores.

【 授权许可】

Unknown