Recent advances in spontaneous imbibition with different boundary conditions

Abstract

Spontaneous imbibition plays an important role in many practical processes, such as oil recovery, hydrology, and environmental engineering. The past few years have witnessed a rapid development in the mechanism analysis and industry applications of spontaneous imbibition. In this paper, we focus on boundary conditions of spontaneous imbibition, which has important effects on the imbibition rate and efficiency. Various boundary conditions are first generated using different capillary model and introduced focusing on the fundamental physical mechanisms. Then, the studies of spontaneous imbibition in core scale are reviewed. The feature is discussed and the relative permeability for coand counter-current imbibition is analyzed. The scaling of imbibition data with different boundary conditions is also presented by combination of experimental and numerical methods. An analytical model to describe spontaneous imbibition is provided at the end.

Effects of Fracture Characteristics on Spontaneous Imbibition in a Tight Reservoir

“…The scaling equation (MK model) defines the dimensionless time of imbibition as where μ w is the wetting phase viscosity, Pa·s and t is the imbibition time, s.…”

“…Through the experiments, Qin found that the presence of cemented minerals may affect the pore structure and wettability. In addition, during the fracturing process, the fracture network in the shale reservoir is complex, and the contact position and area of water and rock surfaces are different, some surfaces cannot be exposed to water, and boundary conditions also have a great influence on imbibition. , There is great significance in studying the influence of fracture types, cemented minerals, and boundary conditions on the imbibition in shale gas reservoirs.…”

An experimental study of imbibition process and fluid distribution in tight oil reservoir under different pressures and temperatures

“…To study the influence of different boundaries on imbibition, Meng and Cai (2018) reviewed the imbibition research at core scale, analyzed the relative permeability of imbibition, and finally discussed the analysis model of imbibition. Previous results show that the dynamic imbibition efficiency firstly increases and then decreases with increasing displacement velocity, and reaches a dynamic balance between imbibition and displacement at a flow rate of 0.04 mL/min, which is also the flow rate at which the imbibition efficiency is maximized.…”

Modeling Water Imbibition and Penetration in Shales: New Insights into the Retention of Fracturing Fluids

“…34 Investigations have been conducted to explain the relationship between the low flowback efficiency and the high deliverability of shale gas wells, and several plausible mechanisms have been proposed (Figure 1): (1) The fracturing water will drain gas from the rock matrix to hydraulic fractures by cocurrent imbibition. 35,36 (2) The imbibed water can exchange gas during the countercurrent imbibition process. 37,38 (3) Water stratification in fractures through gravity drainage dissipates water block and allows gas flow.…”

“…Three typical kinds of conceptual illustration of water imbibition from hydraulic fractures into the shale matrix. (a) Cocurrent imbibition.Fracturing water drains gas from the rock matrix to hydraulic fractures by cocurrent imbibition 35,36. (b) Countercurrent imbibition.…”