Experimental study on strengthening and improving the anti-collapse and wall protection performance of solid-free flushing fluid

Abstract:

In order to improve the wall protection and anti collapse performance of solid-free flushing fluid during geological core drilling， five types of curing agents were selected， including alicyclic curing agent EPR， fatty curing agent DETA， AEP， aromatic curing agent PU， and amide curing agent PET. The use of curing agents can improve the film hardness， adhesion， weather resistance， and increased glossiness of the cured material. Adding curing agents to solid-free flushing fluid can improve the anti collapse performance. Through core immersion tests and linear expansion tests， it was determined that curing agents EPR and PU have a good effect on improving the anti collapse performance of the wall protection. Then， EPR and PU were compounded， and the optimal ratio of EPR∶PU=1∶4 was determined through core soaking test results. Finally， the optimal dosage of curing agent was determined to be 0.2% through linear expansion test and rheological performance test. The dosage of the solid-free flushing fluid is water+0.5% polyacrylamide + 0.04% EPR +0.16% PU， which improves the anti-clapse and wall protection performance with little impact on the rheological property of the flushing fluid.

Key words:geological core drilling;curing agent;core immersion tests;linear expansion tests;anti collapse and wall protection performance