Investigation of some locally water-soluble natural polymers as circulation loss control agents during oil fields drilling

摘要

Eliminating or controlling lost circulation during drilling process is costly and time-consuming. Polymers play an important role in mud loss control for their viscosity due to their high molecular weight. In this paper, three natural cellulosic polymers (carboxymethyl cellulose, guar gum and potato starch) were investigated as lost circulation control material by measuring different filtration parameters such as; spurt loss, fluid loss and permeability plugging tester value according to the American Petroleum Institute (API) standard. The experiments were conducted in a permeability plugging apparatus (PPA) at a differential pressure of 100 and 300psi, using 10, 60 and 90 ceramic discs. From the obtained data, it was found that the 0.1% from the carboxymethyl cellulose exhibited the best results in the filtration parameters among 0.3% guar gum and 0.6% potato starch. At the same time the carboxymethyl cellulose (CMC) enhanced the rheological properties of the drilling mud better than the two other used natural polymers in the term of gel strength, thixotropy, plastic and apparent viscosity. These results were discussed in the light of the adsorption and micellar formation.