Patent ID: 8307916

Claim:
A system for controlling fluid loss in a target formation in an oil or gas well, the well comprising a wellbore extending from a well head at the surface through a target formation, the system comprising: a tubular conduit having a diameter small enough to be received in the wellbore and having a length sufficient to extend from the well head to the target formation; a volume of delivery fluid; and a load of fluid control pods, wherein each pod comprises a discrete mass of swelling agent contained within a container formed of porous, deformable, elastic material, wherein each pod is sized to pass through the conduit into the target formation with the delivery fluid so that the load of pods can be pumped into the formation through the conduit using the delivery fluid, wherein the container material allows the swelling agent to swell but to keep the pod intact in the formation, and wherein the container material has a frictional surface that will frictionally engage surfaces of the formation and surfaces of adjacent pods in the load of pods.