Interface affinity agent used for well cementation by water-based drilling fluid for horizontal well

Abstract

The invention discloses an interface affinity agent used for well cementation by water-based drilling fluid for a horizontal well, which solves the problem of poor quality of a mud cake after leak-off of the water-based drilling fluid for the horizontal well. The interface affinity agent is composed of a mud cake structure conditioning agent, a mud cake reinforcing agent, an interface adhesive and an interface cleaning compound; wherein the weight part of the mud cake structure conditioning agent to the mud cake reinforcing agent to the interface adhesive to the interface cleaning compound is 1: 0.5: 1.2: 0.5; the above mud cake structure conditioning agent is the calcium carbonate whisker with the diameter between 0.5-10 [mu]m, the mud cake reinforcing agent is ploysilicate aluminium ferric sulphate, the interface adhesive is adhesive polystyrene particles, and the interface cleaning compound is dodecyl glucuronide. The interface affinity agent can effectively reduce the original mud cake thickness, increases the mud cake intensity, reduces the equivalent permeability, increases the interface cementation intensity, and is in favor of increasing the well cementation quality for the horizontal well.

Description

technical field [0001] The invention relates to a cementing material used in the drilling field of oil field development. Background technique [0002] Water-based drilling fluids are widely used in major oil fields at home and abroad due to their advantages of economy, environmental protection and simple process. However, due to the poor quality of the mud cake after filtration, it leaves hidden dangers in interface cementation in later cementing operations. Especially in the cementing process of special process wells such as horizontal wells, the performance of water-based drilling fluid and the quality of mud cake have a particularly prominent impact on the cementation of the cementing interface. According to incomplete statistics, the high-quality cementing rate of horizontal wells using water-based drilling fluids is about 20% lower than that of oil-based drilling fluids, and one of the important influencing factors is the difference in mud cake quality. The reason is...

AI Technical Summary

Problems solved by technology

The reason is: in the horizontal section drilling project, the mud cake on the well wall becomes thicker and thicker due to the continuous fluid loss of the water-based drilling fluid, and the drilling cycle is longer. The cycle is long, water-based drilling fluid is continuously leaked to the well wall, and the virtual mud cake is continuously thickened, resulting in insufficient replacement of the cementing operation, unable to remove the virtual mud cake, and ultimately affecting the cementing quality of the cement sheath and the well wall

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