Solid-Phase Synthesis Of Lignin-Carbonhydrate Complex And Performance Evaluation In Drilling Fluids

Lignin is one of the traditional drilling fluids treatment agent, performed AV reduction and good temperature resistance in drilling fluids; Polysaccharide is a modern new type of environmentally friendly drilling fluids treatment agent, performed AV increase, proving lubrication,FL reduction but poor temperature resistance in drilling fluids. In order to combine the advantages of the two types of compounds, improve temperature resistance of polysaccharide and application of lignin, this paper explores the feasibility of preparation of LCC by solid-physe synthesis.DSC was used to determine the reaction temperature range at first. According to the temperature range, alkali lignin-polysaccharide PG (SPS-ALCCPG), alkali lignin-polysaccharide SJ (SPS-ALCCSJ), lignin sulfonate-polysaccharide PG (SPS-SLCCPG) and lignin sulfonate-polysaccharide SJ (SPS-ALCCSJ) were synthetized by alkali lignin, lignin sulfonate, polysaccharide PG and polysaccharide SJ. The structures of the products were charactered by IR and the performances as drilling fluids additive were evaluated in4%freshwater drilling fluids and compared with the mixture named SM-ALCCPG, SM-ALCCSJ, SM-SLCCPG and SM-SLCCSJ.The results showed that:the best reaction temperature range is160-180℃. The SM-LCC could increase AV and reduce the FL of the drilling fluids but perform poor temperature resistance and shear thinning behavior under room temperature in4%freshwater drilling fluids. SPS-ALCC performed differently in drilling fluids which synthetized by different conditions. Most of SPS-LCC performed higher AV increment than that of SM-LCC while part of them could reduce AV and FL. Moreover, the samples showed well performance of temperature resistance, shear thinning behavior mud cake lubricity and shale inhibition.