A valve assembly for delivering a fluid into a wellbore includes a stationary valve assembly that is installed on a production tube that extends down into the wellbore. A dynamic valve assembly that is attached to a capillary line is lowered into the production tube, and the dynamic valve assembly releasably latched onto the stationary valve assembly. The latching of the dynamic valve assembly to the stationary valve assembly also opens a fluid connection between the dynamic valve assembly and the stationary valve assembly, thereby allowing pressurized fluid to flow from the capillary line into the wellbore via the stationary valve assembly. When it is necessary or desirable to perform maintenance or repair operations on the dynamic valve assembly or the capillary line, the dynamic valve assembly and the attached capillary line can all be withdrawn to the top of the well.