Research Of Composite Ionic Polymer Gel Plugging Agent

Lost circulation is the problem of restricting drilling progress and increasing drilling cost seriously during the drilling engineering. At present, most of plugging materials are rigid materials which have poor adaptability of the leakage layer. Some plugging materials have poor capability of absorbing water to expand so that they can not go into the deeper leakage layer, leading to secondary leakage. Developed in this paper, the polymer gel has good deformation ability, water absorption expansion still has the high elasticity and toughness, able to adapt to different sizes of leakage layer, can further internal leakage layer to fill leakage layer.Developed in this paper, the polymer gel has polymerization reaction with these three monomer poly:acrylamide (AM),2-acrylamide-propyl sulfonic acid (AMPS) and N-N2methyl acrylamide (DMAM), and adding sodium base bentonite (MMT) to enhance the strength of the polymer.We have studied the factors affecting the performance of polymer gel to choose the ideal synthetic formula through. We optimize the synthetic formula and get the optimal reaction conditions by single factor analysis:ratio of monomer (AM:AMPS:DMAM):8:1:1, crosslinking agent added amount as follows:0.08%, sodium base bentonite added amount: 40%, monomer concentration:23.5%, the initiator added amount:0.18%, pH value is 7. The polymer gel has high intensity and large swelling radio.In this paper, The polymer gel has good compatibility. Drilling fluid, formation water and oil have a little effect on the performance of the polymer gel. In the indoor simulation experiments, the polymer gel has ability to work under pressure 0.5MPa. The polymer gel with other materials can work under pressure 7MPa. The polymer gel has good temperature resistance so that it can keep good nature under 100 ?.