Mud cake hardening enhancer for drilling fluid

Abstract

The invention discloses a mud cake hardening enhancer for drilling fluid. The enhancer is characterized by composing polysiloxane, a mud cake hardener, a low molecular weight polymer, a film former and an organic chelating agent; the mass ratio of the mud cake hardener, the low molecular weight polymer, the film former and the organic chelating agent is 30-45:35-50:5-12:8-15:2-8. By adding the mudcake hardening enhancer to the drilling fluid and completion fluid, the properties of a drilling fluid mud cake can be effectively changed, the quality of the drilling fluid mud cake can be improved,the thickness of the mud cake can be reduced, the thin and tough mud cake can be formed, the strength of the mud cake can be increased, thereby improving the interface cementation strength during well cementing, the physical combination of a cementing interface is transformed into chemical affinity, thereby improving the interface cementation quality between the mud cake and a cement ring and a casing and the cement ring, the interface cementation permeability rate is reduced, the cementing quality rate is improved, the service life of oil and gas wells is prolonged, and a crude oil recoveryratio is correspondingly improved.

Description

Technical field [0001] The invention relates to drilling fluid additives in petroleum drilling engineering. More specifically, it relates to a mud cake hardening enhancer for drilling fluid. Background technique [0002] Cementing construction is one of the important processes in the production process of oil and gas wells. The main purpose of cementing is to seal the formation, seal the oil, gas, and water layers, prevent fluids from flowing between the formations, and protect the production layer. In other words, if a well wants to achieve its due productivity, it mainly depends on the quality of the interlayer packing achieved during the cementing process. When the cementing quality is not good, interlayer channeling and out-of-pipe collapse will occur after production, which will seriously affect the subsequent oil and gas production and well life. [0003] Theoretically speaking, the cementing interface should actually be the cementation interface between the solidified body...

AI Technical Summary

Problems solved by technology

The drilling mud cake hardening enhancer disclosed in Chinese patent document CN 104119843A has improved the sealing quality of the cementing interface and the cementing strength of the two cementing interfaces to a certain extent, so that the high-quality rate of the cementing has increased by 30.6 percentage points; Improvements: The bonding strength of the first cementing interface is increased by less than 10%, especially the cementing strength of the second cementing interface is increased by less than 30%.

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