Unconsolidated formations where heavy oil or tar is the matrix have hindered the production in oil wells as well as water wells ever since wells have been drilled. Early assumptions were that the sand in the oil had to be lived with. Curtailed producing rates were sometimes used to alleviate sand production.
The problem in tar sands is the undesirable production of sand with the oil or bitumen which is detrimental to most equipment, and particularly to the pumps.
Unconsolidated or poorly consolidated sands or formations are a significant problem to a great degree, particularly in Canada, Texas, Louisiana, and California, on both land and offshore. Sanding is a problem all over the world from the Gulf of Mexico to Venezuela to Nigeria.
Different methods for controlling the migration of sand from unconsolidated formations or tar sands are screens, gravel packs, or agglomerating the formation in place with chemicals. The instant disclosure utilizes a new combination of the above.
U.S. Pat. No. 3,379,247 circulates hot fluids between lower and upper perforations in a tar sand formation, but is also produces sand with the melted bitumen which is detrimental to most mechanical equipment above, as the hydraulic pumps, etc. Assignee's U.S. Pat. No. 3,913,671 discloses circulating an aqueous heating fluid with sodium hydroxide out upper performations and in lower perforations after packing through a sand pack. But this disclosure lacks the steps of running a wash pipe through the screen with a nozzle on lower end thereof and breaking off the nozzle for enlarging the screen opening among other structural features for providing an improved system of sand control and production of bitumen. U.S. Pat. No. 2,905,245 likewise lacks the screen and gravel pack therewith for providing the disclosed improved method for hydrocarbon production in tar sands. U.S. Pat. No. 3,910,351 discloses a pile of granular material around a slotted tube in a cavity, but the granular material fills the cavity completely with no provision for penetration by a screen. U.S. Pat. No. 3,812,913 shows a different method of formation consolidation wherein a bonding agent is applied to the formation.
USPTO Backgrounds
USPTO Backgrounds