| 摘要 |
A dispersion liquid for supporting oil drilling, including: an aqueous medium and a particulate solid polyglycolic acid resin dispersed in the aqueous medium; wherein the particulate polyglycolic acid resin has a weight-average molecular weight of at least 70,000 and at most 500,000, and exhibits weight retentivities in water at 80° C. of at least 85% after 12 hours, at most 80% after 72 hours, and at most 45% after 168 hours. The particulate solid polyglycolic acid resin included in the above-mentioned dispersion liquid for supporting oil drilling, functions as a fluidity control material exhibiting ideal degradation charateristics in the drilling operation for expansion of oil production capacity, demanded for suppressing the liquid permeability in the early stage and recovery of the liquid permeability after completion of the operation of the formation around the oil well. |
