Method and device for controlling viscous fingering in surfactant oil displacement through gravity effect

Abstract

The invention relates to a method and device for controlling viscous fingering in surfactant oil displacement through the gravity effect. The method for controlling viscous fingering in surfactant oildisplacement through the gravity effect sequentially comprises the steps that an injection-production seepage inclination angle adjustable type sand-filling physical model is designed; the seepage velocity of surfactant solution displacing phase forming is related to the seepage velocity of microemulsion slug interface area forming under the gravity effect; the seepage velocity of microemulsion slug forming is related to the seepage velocity of 'oil wall' interface area propulsion under the gravity effect; physical model unitary surfactant leading displacement edge and seepage physical property parameter obtaining are conducted; and the leading displacement edge is stabilized through the gravity effect to remove oil saturation. According to the method and the device, the problems that inexisting surfactant oil displacement, in order to effectively avoid viscous fingering, a polymer-type mobility control agent often needs to be introduced into a system, consequently the oil productioncost is further increased, and the ground injection-production technology is complicated are solved, and means and bases can be provided for more comprehensive describing of the unitary surfactant displacement seepage characteristics and oil-displacement mechanism in tertiary oil production.

Description

1. Technical field: [0001] The present invention relates to how to use the gravity-assisted effect to stabilize the displacement front and control the viscous fingering behavior when solving the lack of mobility control agent in the surfactant flooding, and how to use the gravity-assisted effect for the surfactant oil recovery well pattern. The technical problem of how to optimize the deployment mode is specifically related to the method and device for controlling viscous fingering in surfactant flooding by using the gravity effect. 2. Background technology: [0002] Chemical flooding technology has accounted for more than 70% of the reserves covered by the application of enhanced oil recovery methods in China. Although viscoelastic polymer flooding is the most widely used, with the continuous approaching of the limit of polymer flooding efficiency In the exploration and development of complex types of oil reservoirs, under the background of the virtuous cycle of oilfield re...

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Problems solved by technology

[0003] However, due to the lack of mobility control agents represented by polymers and the low viscosity of its own aqueous solution, mono-surfactant flooding will have a prominent viscous fingering behavior in heterogeneous reservoirs, which will result in more porous media. In the process of phase seepage, the displacement front advances unstable and directly affects its displacement efficiency

Although the large-scale and high-speed development and application of horizontal well technology provide convenience and superior conditions for gravity-assisted oil recovery, there are also related exploratory studies in the composite flooding method involving surfactants (Si Le Van, Bo Hyun Chon, Energies, 2016, 9(4): 244), but for surfactant flooding, how to exert the gravity-assisted effect to control viscous fingering, how to determine the limit of seepage parameters in the process of gravity-assisted effect, and the corresponding gravity effect under the change of reservoir geological conditions How to optimize the deployment of oil production well pattern instead of mobility control agent is still a blank, and it is also a difficult problem and an urgent problem to be solved in the popularization and application of one-component surfactant flooding technology

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