High Temperature Fluid Loss Agent .amps / Fa / Dmam / Nvp Study

Concerning the problems in Exploitation of high temperature and pressure reservoir, this research was carried out under the theoretical guidance of polymer chemistry. Through the application of four types of monomers as raw materials:2-Acrylamido-2-Methylpropane Sulfonic Acid (AMPS), Fumaric acid (FA), N, N-dimethyl acrylamide (DMAM),vinyl pyrrolidone (NVP), and sodium persulfate as the initiator,the synthesis of water-soluble AMPS/FA/DMAM/NVP quaternary copolymer was achieved in this research.Taking the improvement of conversion rate and the molecular weight of the polymer as two evaluation criteria, the influence of synthesis conditions on conversion rate and intrinsic viscosity was surveyed in this research. The synthesis conditions of the quaternary copolymer are confirmed: monomer mass ratio m(AMPS):m(FA):m(DMAM):m(NVP)=4/2/2/2, initiator amount 0.36%(wt), pH of reaction 7, temperature of reaction 50℃and concentration of monomers 15%.The product's structure was verified by Fourier transform infrared spectrum (FTIR) and hydrogen nuclear magnetic resonance spectrum (1H-NMR). The decomposition temperature is 320℃by thermogravimetry (TG) analysis. This polymer had excellent thermal stability.On the basis of the cement slurry water loss, this research studied the influence of different synthesis conditions on the performance of the copolymers in general well cement slurries, the results of which showed that the influence of synthesis conditions upon the performance of the copolymers in general well cement slurries is entirely consistent with that of synthesis conditions upon intrinsic viscosity, consequently, such regularity was explored in this dissertation.This research explored the influence of the amount of the fluid loss additive upon the water loss of fresh water cement slurry, which manifested that the water loss will decrease with increasing amount of fluid loss additive and the water loss will be reduced to the minimum if the amount of the fluid loss additive takes up 1.2%(BWOC).The performance of AMPS/FA/DMAM/NVP was evaluated. When the temperature is 180℃, the water loss of fresh water cement slurry can be controlled under 60mL,1.2% AMPS/FA/DMAM/NVP (BWOC).When the temperature is 180℃and the NaCl content is 32%, the water loss can be controlled under 100mL,1.2% AMPS/FA/DMAM/NVP.The performance of cement slurry mixed with AMPS/FA/DMAM/NVP was evaluated in this study, and it showed that cement slurry added by AMPS/FA/DMAM/NVP performs very well in its rheological property, besides, the liquidity index and consistency coefficient of neat cement slurry can be significantly improved by applying dispersant. It also revealed that the compressive strength of set cement will decrease after being added by the quaternary copolymer, however, the decreasing extent is not obvious while the temperature is increasing. Therefore, the technical requirement of cementing operation and can be satisfied through the application of strengthening agent. The observation of the configuration of slurry filter cakes by scanning electron microscopy (SEM) andζ-potential measurement of cement slurry revealed the function mechanism of AMPS/FA/DMAM/NVP:reducing the porosity of slurry filter cakes and avoiding the formation of flocs structures.