Process for preparing drilling fluid thinner by modification of alkaline pulp black liquor

Abstract

The preparation method for alkali method of viscosity-reducing agent is to condense the sewage from modified alkaline pulping to let the lignin content more than 25-35% and put into temperature-controlled kettle for stepwise modification. The product has well performance up to effect by FCLS for wide application range. This invention is simple and low cost.

Description

technical field [0001] The invention relates to a process for preparing drilling fluid viscosity reducer by using modified alkaline pulping waste liquid. Background technique [0002] Viscosity reducer is an indispensable drilling fluid treatment agent in the drilling process, and it plays a very important role in adjusting the rheology of drilling fluid. [0003] Most of today's paper mills use alkaline pulping, and alkali lignin is one of the main components in the black liquor of alkaline pulping. Therefore, the source of alkali lignin is abundant and the price is low. However, due to the complex structure and polydispersity of alkali lignin, and its unsatisfactory water solubility, the output of alkali lignin oilfield chemicals is not commensurate with the scale of black liquor discharged by the paper industry. At present, industrial lignin other than fuel is mainly lignin sulfonate, which is widely used in the modification and production of iron chromium lignosulfonat...

AI Technical Summary

Problems solved by technology

Chromium-free lignin-based viscosity reducers are generally not strong in temperature resistance, and they need to have a good effect at a high pH of 10-12; although inorganic viscosity reducers have good viscosity reduction performance and good temperature resistance, their resistance The performance of salt is not good, and some cause pollution to the environment; the organic viscosity reducer has good temperature resistance, especially salt resistance, but there is a small amount of addition, which is easily consumed in field application and needs to be added frequently, and the cost is high , the disadvantage of narrow application range

At present, although some chromium-free drilling fluid viscosity reducers have been developed, there are some problems such as poor effect, unstable performance, large dosage and high price.