Vertical flooding method of oil recovery

Claim 1

A METHOD FOR RECOVERING OIL FROM A SUBTERRANEAN RESERVOIR BY VERTICAL FLOODING WITH AN INJECTED FLUID WHICH COMPRISES: (A) PROVIDING SPACED-APART INPUT AND OUTPUT WELL MEANS FOR CONVEYING FLUIDS BETWEEN THE EARTH''S SURFACE AND A SUBTERRANEAN FORMATION CONTAINING OIL, (B) INJECTING A FLUID FOR DISPLACING OIL FROM THE INPUT WELL MEANS INTO THE FORMATION, SAID FLUID BEING INTRODUCED INTO SAID FORMATION AT AN UPPER HORIZON WHEN SAID FLUID IS LESS DENSE THAN THE OIL AND AT A LOWER HORIZON WHEN SAID FLUID IS MORE DENSE THAN THE OIL, AND THE FLUID BEING INJECTED AT THE RATE WHERE THE MAGNITUDE OF THE VISCOUS FORCES IS DECREASED REALTIVE TO THE GRAVITATIONAL AND CAPILLARY FORCES, WHICH FORCES EXIST BETWEEN THE FLUIDS AND THE FORMATION, SUFFICIENTLY TO MAINTAIN THE INJECTED FLUID INTERFACE WITH THE OIL SUBSTANTIALLY HORIZONTAL UNTIL SAID INJECTED FLUID EXTENDS FROM THE INPUT WELL MEANS TOWARD THE OUTPUT WELL MEANS, (C) PRODUCING OIL FROM SAID OUTPUT WELL MEANS AT A RATE NOT ABOVE THE RATE AT WHICH THE FLUID IS BEING INJECTED INTO THE INPUT WELL MEANS, SAID OIL BEING PRODUCED FROM ONE OF THE FORMATION''S OIL PRODUCING HORIZONS, (D) WHEN THE INJECTED FLUID EXTENDS HORIZONTALLY SUBSTANTIALLY TO THE DESIRED LATERAL DISTANCE FROM THE INPUT WELL MEANS TO THE OUTPUT WELL MEANS, INCREASING THE RATE AT WHICH THE FLUID IS INJECTED INTO THE INPUT WELL MEANS BUT NOT TO SUCH MAGNITUDE THAT THE FORMATION IS FRACTURED CONTINUOUSLY THEREBY. (E) PRODUCING OIL FROM THE OUTPUT WELL MEANS AT AN INCREASED RATE BUT NOT EXCEEDING THAT RATE AT WHICH THE FLUID IS THEN BEING INJECTED, AND SAID OIL BEING PRODUCED AT A HORIZON VERTICALLY OPPOSITE FROM THE HORIZON AT THE INPUT WELL MEANS INTO WHICH FLUID IS BEING INJECTED INTO THE FORMATION, (F) CONTROLLING THE RATE OF OIL PRODUCTION AT A MAGNITUDE SLIGHTLY BELOW THAT CRITICAL RATE OF PETROLEUM PRODUCTION WHERE OPPOSING DIFFERENTIAL GRAVITATIONAL FORCES ACTING ON THE HORIZONTAL FLUID-OIL INTERFACE ARE EXCEEDED BY THE PRESSURE GRADIENTS IN THE FORMATION ADJACENT THE OUTPUT WELL MEANS TO DISRUPT THE PLANAR INTERFACE, AND (G) SAID OIL PRODUCTION BEING CONTINUED UNTIL A SUBSTANTIAL PART OF THE FORMATION IS FILLED WITH THE INJECTED FLUID.

Claim 2

A METHOD FOR RECOVERING OIL FROM A SUBTERRANEAN RESERVOIR BY VERTICAL FLOODING WITH AN INJECTED FLUID WHICH COMPRISES: (A) PROVIDING SPACED-APART INPUT AND OUTPUT WELL MEANS FOR CONVEYING FLUIDS BETWEEN THE EARTH''S SURFACE AND A SUBTERRANEAN FORMATION CONTAINING OIL, (B) INJECTING A FLUID FOR DISPLACING OIL FROM THE INPUT WELL MEANS INTO THE FORMATION, SAID FLUID BEING INTRODUCED INTO SAID FORMATION AT AN UPPER HORIZON WHEN SAID FLUID IS LESS DENSE THAN THE OIL AND AT A LOWER HORIZON WHEN SAID FLUID IS MORE DENSE THAN THE OIL, AND THE FLUID BEING INJECTED AT THE RATE WHERE THE MAGNITUDE OF THE VISCOUS FORCES IS DECREASED REALTIVE TO THE GRAVITATIONAL AND CAPILLARY FORCES, WHICH FORCES EXIST BETWEEN THE FLUIDS AND THE FORMATION, SUFFICIENTLY TO MAINTAIN THE INJECTED FLUID INTERFACE WITH THE OIL SUBSTANTIALLY HORIZONTAL UNTIL SAID INJECTED FLUID EXTENDS FROM THE INPUT WELL MEANS TOWARD THE OUTPUT WELL MEANS, (C) PRODUCING OIL FROM SAID OUTPUT WELL MEANS AT A RATE NOT ABOVE THE RATE AT WHICH THE FLUID IS BEING INJECTED INTO THE INPUT WELL MEANS, SAID OIL BEING PRODUCED FROM ONE OF THE FORMATION''S OIL PRODUCING HORIZONS, (D) WHEN THE INJECTED FLUID EXTENDS HORIZONTALLY SUBSTANTIALLY TO THE DESIRED LATERAL DISTANCE FROM THE INPUT WELL MEANS TO THE OUTPUT WELL MEANS, INCREASING THE RATE AT WHICH THE FLUID IS INJECTED INTO THE INPUT WELL MEANS BUT NOT TO SUCH MAGNITUDE THAT THE FORMATION IS FRACTURED CONTINUOUSLY THEREBY. (E) PRODUCING OIL FROM THE OUTPUT WELL MEANS AT AN INCREASED RATE BUT NOT EXCEEDING THAT RATE AT WHICH THE FLUID IS THEN BEING INJECTED, AND SAID OIL BEING PRODUCED AT A HORIZON VERTICALLY OPPOSITE FROM THE HORIZON AT THE INPUT WELL MEANS INTO WHICH FLUID IS BEING INJECTED INTO THE FORMATION, (F) CONTROLLING THE RATE OF OIL PRODUCTION AT A MAGNITUDE SLIGHTLY BELOW THAT CRITICAL RATE OF PETROLEUM PRODUCTION WHERE OPPOSING DIFFERENTIAL GRAVITATIONAL FORCES ACTING ON THE HORIZONTAL FLUID-OIL INTERFACE ARE EXCEEDED BY THE PRESSURE GRADIENTS IN THE FORMATION ADJACENT THE OUTPUT WELL MEANS TO DISRUPT THE PLANAR INTERFACE, AND (G) SAID OIL PRODUCTION BEING CONTINUED UNTIL A SUBSTANTIAL PART OF THE FORMATION IS FILLED WITH THE INJECTED FLUID.