摘要 |
A well chemical dispensing system includes a tubular sub for securing into a drill string. A ball stop is located within the passage. A ball filled with a liquid surfactant is pumped down the well. The ball is formed of a frangible material for shattering on impact with the ball stop, so as to dispense the surfactant, causing foaming when mixing with well fluid. Struts within the ball extend across an interior of the ball and join to inner surfaces of the ball. The struts are formed of a solid surfactant material. The ball has a spherical shape with dimples formed in an exterior surface of the sphere. A spring in the passage applies an upward force on the ball stop. The ball stop has upper and lower grids extending across the passage.
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