Multi-slug plugging agent for bottom water reservoir and plugging method thereof

Abstract

The invention provides a multi-segment plugging agent for bottom water reservoirs and a plugging method thereof. The multi-segment plugging agent for bottom water reservoirs includes foam jelly plugging agents, foam gel plugging agents and reinforced foam plugging agents , when there are no artificial fractures or / and natural fractures in the plugged well, no foam jelly plugging agent is needed for plugging, and each plugging agent is injected into the plugged well in sequence, and the well is shut in for 5-7 days to complete Multi-slug plugging in bottom water reservoirs. The reinforced foam plugging agent of the present invention is mainly used for plugging cracks. Both the foam gel plugging agent and the reinforced foam plugging agent have strong oil-water selectivity, ensuring that the oil layer is not damaged on the basis of plugging bottom water, and can Increase the treatment radius, effectively seal off the water layer, prevent coning, and ensure the liquid volume of the oil well in the later stage of production.

Description

technical field [0001] The invention belongs to the technical field of oil and gas field development, and in particular relates to a multi-segment plugging agent for bottom water oil reservoirs and a plugging method thereof. Background technique [0002] The development of bottom water reservoirs is one of the difficult problems in oilfield development worldwide. In the development of bottom water reservoirs, the outstanding problem is that with the production of crude oil during the production process, it is easy to cause bottom water coning or ridge ingress, resulting in flooding of production wells, reducing sharply, and the speed of water coning is very fast. Going to the bottom of the oil well, the oil well will be flooded very quickly, and the water cut will rise to 100%. Jurassic bottom water reservoirs in the Ordos Basin have thick bottom water layers, large reserves, and low formation permeability, and they are basically put into production after fracturing. Among...

AI Technical Summary

Problems solved by technology

Among them, the mechanical plugging is easily limited by the well conditions. Once the wellbore has problems such as casing deformation and dislocation, the packer and other large tools cannot be lowered into the wellbore. In addition, the mechanical water plugging method is only carried out in the wellbore. However, if the formation cannot be sealed outside the wellbore, as the oil well continues to produce, the bottom water will continue to cone into the oil well along the formation

The soft diaphragm is mainly achieved by injecting foam, gel or inorganic plugging agent. Due to the weak plugging ability of the injected foam system, it is almost impossible to plug the oil reservoirs with large pressure difference and natural and artificial fractures. Its validity period is also very short, which cannot meet the needs of oilfield production; although gel or inorganic water shutoff agents have high strength, the main problem is that the injection volume and system strength cannot be controlled accurately, and when the injection volume and strength are small, fracture plugging If the injection rate and intensity are large, there is a risk that the production layer will be blocked as a whole (no fluid production after plugging). At the same time, due to the large injection plugging dose of the oil well, it will be difficult to drain liquid in the later stage, and there is a risk of being flooded by the injected liquid. Problems such as death or difficulty in increasing production in the later stage