| abstract |
The invention relates to the use of a copolymer of N-substituted acrylamide and N-alkenyl caprolactam as a fluid loss reducer for drilling fluid with hydrate inhibiting performance. The copolymer formed from ethylene acrylamide and N-alkyl caprolactam in the invention is applied to hydrate inhibitor and fluid loss control agent in drilling fluid. The weight-average molecular weight of the copolymer is 10,000-2,000,000, the ratio of polymerization units is 0.1-10, the use mass concentration is 0.5-3%, and the use pressure is between 1-30 MPa. The new treatment agent of the present invention combines the natural gas hydrate inhibitor and the fluid loss control agent in the drilling fluid treatment agent, realizes two functions with one treatment agent, reduces the cost of the drilling fluid, and improves the hydrate inhibition performance and reduces the oil loss. The stability of drilling fluid is guaranteed under the premise of fluid loss performance. |