A kind of magnetic nanometer plugging agent and preparation method thereof

Abstract

The invention discloses a magnetic nano plugging agent for drilling fluid and a preparation method of the plugging agent. A preparation process comprises the following steps of: adding magnetic nano particles into a dispersion medium and then adding surface modification molecules; uniformly mixing, and heating to react for certain time; and then filtering and drying to obtain the magnetic nano plugging agent. The magnetic nano plugging agent and the preparation method thereof have the advantages that the preparation method of the magnetic nano plugging agent is simple, the process cost is low and industrial production is easy to realize; the grain diameter of the prepared nano plugging agent is small, so that the nano plugging agent can be used for effectively plugging a tiny hole, a micro-crack stratum, and particularly a mud shale stratum; the nano plugging agent has magnetic field responsiveness, and in a drilling process, the nano plugging agent can selectively plug a specific stratum, so that the plugging efficiency is improved. The magnetic nano plugging agent is added into the drilling fluid to obviously improve the comprehensive performance of the drilling fluid; when the magnetic nano plugging agent is used for drilling the tiny hole, the micro-crack stratum and the mud shale stratum, a good effect is obtained.

Description

technical field [0001] The invention relates to a magnetic nano-blocking agent for drilling fluid and a preparation method thereof, belonging to the field of nano-materials in oil and gas fields. Background technique [0002] During the drilling process, the fluid, solid particles and other additives in the drilling fluid leak into the formation, which will cause damage to the formation and often lead to problems such as instability of the wellbore wall. If it is in the oil and gas layer, it will also pollute the oil and gas reservoir, or even block the pores of the reservoir and reduce the permeability of the reservoir. In order to prevent the fluid, solid particles and other additives in the drilling fluid from leaking into the formation, an effective method is to add a plugging agent to the drilling fluid to effectively seal the pores of the wellbore rock during the drilling process, thereby reducing or even eliminating the drilling fluid. Liquid leakage into the formati...

AI Technical Summary

Problems solved by technology

[0003] At present, the commonly used plugging materials have large particles and can effectively plug formations with large pores, but it is difficult to achieve effective plugging for formations with small pores and micro-fractures, especially shale formations