Synthesis and characterization of starch‐graft‐polyacrylamide copolymers and their application as filtration control agents in drilling fluid

Abstract

Some starch-graft-polyacrylamide copolymers were prepared by the polymerization of corn starch with acrylamide in aqueous medium using a complex initiation system consisting of ceric ammonium sulphate and ammonium persulphate. The copolymers were applied to water-based drilling fluid as filtration control agents. Their grafting parameters such as percentage of grafting, grafting efficiency, and solution viscosity (g) were investigated by using elemental analyzer and rotational viscometer. The results showed that increases in initiator concentration and reaction temperature first favored and then impeded the grafting reaction. Grafting of acrylamide onto starch increased with the increase of monomer concentration. It also increased with increasing reaction time up to a certain degree and then leveled off. For the graft copolymers, a higher percentage of grafting and higher g were beneficial in decreasing the filtrate volume of water-based drilling fluid, even under an operating environments of 1478C and saturated salinity. A possible mechanism is proposed to interpret the improvement of fluid loss properties.

Viscoelastic properties of borax loaded CMC‐g‐cl‐poly(AAm) hydrogel composites and their boron nutrient release behavior

“…Here, W NaCMC, W BSAPC , and W BSAPCx are the weight of NaCMC, BSAPC before and after extraction of homopolymer, respectively. AM homopolymer was removed by Soxhlet extraction with a 60:40 (V/V) mixture of ethylene glycol and acetic acid for 2 h …”

Avaliação de amidos modificados empregados na mineração para aplicação em fluidos de perfuração de poços de petróleo

“…De acordo com GUO e PENG [3] e ALFORD et al [4], a perda elevada de filtrado pode levar ao aumento do custo do fluido, formação de reboco excessivamente espesso, instabilidade do poço e danos à formação permeável.…”

“…Uma das funções mais críticas dos fluidos é tentar minimizar a quantidade de filtrado que invade a formação porosa e permeável [5]. Para conseguir isto, foram desenvolvidos e aplicados agentes de controle de filtração incluindo materiais naturais, naturais modificados e totalmente sintéticos [3]. Os controladores de filtrado formam um reboco de baixa permeabilidade que impede a invasão da fase líquida do fluido para as formações permeáveis [6,7].…”

Properties of starch–polyglutamic acid (PGA) graft copolymer prepared by microwave irradiation − Fourier transform infrared spectroscopy (FTIR) and rheology studies

“…The development and preparation of various starch‐graft copolymeric materials have been described in the literature . Thermal processing is the major preparative method to produce starch‐based graft copolymers , which includes reactive blending , reactive extrusion , and microwave irradiation , etc. Recently, microwave irradiation or heating has been widely adopted in polymer synthesis.…”