a two part encapsulated cementing system is mixed downhole in a method of plugging an abandoned well . using this two part system , one of the components is first placed in the well at the desired plugging depth . next , the other component is placed in the well above the first placed component . densities of the components have been selected such that the density of the second placed component is sufficiently higher then the density of the first placed component to facilitate gravity mixing of the two components as the second placed component moves through the first placed component and in the process activation occurs .