Development and evaluation of environment friendly viscosity reducer for high temperature and high density drilling fluid

It is a challenge to control the rheology of water-based drilling fluid at high densities. A new environmental friendly viscosity reducing agent was employed to adjust the rheology of high density water-based drilling fluid under high temperatures. This paper focuses on the study of a new environmental protection viscosity reducing agent FSJ-3 which is suitable for high temperature and high density drilling fluid system. On the basis of 2.40g/cm³ high density mud, the comparison between other viscosity reducers and the viscosity reducer FSJ-3 developed in this paper is investigated. The experimental results show that the new viscosity reducer FSJ-3 has the advantages of good viscosity reduction effect(The viscosity reduction efficiency can reach 20%), strong temperature resistance and superior environmental protection, and is applied in high temperature and high density drilling fluid with good compatibility.