Plugging agent for drilling fluid and preparation method thereof

Abstract

The invention belongs to the field of petroleum engineering, and particularly relates to a plugging agent for drilling fluid and a preparation method thereof. The plugging agent for the drilling fluidis characterized by comprising a mixture a and a mixture b, wherein the mixture a comprises rubber particles and rigid mineral particles, and the mixture b comprises walnut shells, wood fibers and microcrystalline cellulose powder. The method comprises the following steps: (1) uniformly stirring the mixture a, (2) adding the mixture b into the mixture a for at least three times, and stirring for4-6 minutes every time, and (3) then stirring uniformly to obtain the plugging agent. The plugging agent has the effects of collapse prevention, high elasticity and large deformation quantity, has aninhibition effect on a leakage channel which is easy to hydrate, is beneficial to formation of a stable well wall, is compounded with other plugging materials, and has a relatively good collapse prevention and plugging effect.

Description

technical field [0001] The invention belongs to the field of petroleum engineering, and in particular relates to a plugging agent for drilling fluid and a preparation method thereof. Background technique [0002] Lost circulation is a ubiquitous phenomenon during drilling, and other downhole vicious accidents induced by it will cause great harm to drilling engineering, oil and gas field development and reservoir protection. It is not uncommon for major oil fields to abandon wells due to vicious lost circulation. To solve this problem, a plugging agent is added to the drilling fluid in engineering to temporarily seal the drilled layer, that is, to effectively prevent the drilling fluid and the harmful substances in the drilling fluid from entering the reservoir during the drilling process. After well completion, the lost circulation agent can be degraded by itself or removed by simple treatment. [0003] At present, in the plugging agents used in major oil fields, there are ...

AI Technical Summary

Problems solved by technology

[0005] The plugging agent made of existing materials does not have anti-slump performance, and the hydration expansion effect of mud shale is not good in the easily hydration loss zone, and it is prone to secondary or even multiple loss

Moreover, when there is good deformation, the expansion effect is poor, and when there is good expansion, the deformation is poor and does not have anti-slump performance, especially when oil and gas layer plugging operations are performed, oil and gas layer pollution will be caused, and other The loss is even more immeasurable. At this time, it is difficult for this type of product to exert its due effect