Optimization method and device for controlling viscous fingering in surfactant flooding under gravity effect

Abstract

The invention relates to an optimization method and device for controlling viscous fingering in surfactant flooding under the gravity effect. The optimization method for controlling viscous fingeringin surfactant flooding under the gravity effect sequentially includes the steps of design of an injection-production seepage dip angle adjustable sand filling physical model, correlation of a surfactant solution displacement phase under the gravity effect and the seepage speed of an interface region where micro-emulsion slug is formed, correlation of the formed micro-emulsion slug under the gravity effect and the seepage speed of a propelled oil wall interface region, acquisition of unitary surfactant flooding leading edge and seepage physical property parameters of the physical model, the gravity effect stable displacement leading edge de-oil saturation and variable injection and projection dip angle stable seepage technology boundary division and viscous fingering control capacity optimization. The problems that in existing surfactant flooding, in order to effectively avoid viscous fingering, a polymer fluidity control agent needs to be introduced into a system usually, the oil extraction cost is further increased, and a ground injection and production process is complicated are solved.

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. How to optimize the deployment method is a technical problem, specifically related to the method and device for viscous fingering optimization in surfactant flooding controlled by 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 provides 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 HyunChon, Energies, 2016, 9 (4): 244), but for surfactant flooding, how to use the gravity-assisted effect to control viscous fingering, how to determine the limit of seepage parameters in the process of the gravity-assisted effect, and how to replace the corresponding gravity effect under the change of reservoir geological conditions How to optimize the deployment of mobility control agents in production well patterns 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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