Multilayer propping of fractures

Claim 1

A METHOD FOR INCREASING THE PERMEABILITY TO FLUIDS OF A SUBSTANCE EARTH FORMATION HAVING AT LEAST ONE VERTICALLY ORIENTED FRACTURE EXTENDING FROM THE WALL OF THE WELL BORE INTO SAID INFORMATION COMPRISING SUCCESSIVELY INJECTING INTO SAID WELL BORE AND THENCE INTO SAID FRACTURE ALTERNATE DISCRETE SLUGS OF A CARRIER FLUID MIXED WITH INSOLUBLE PARTICLE-FROM SOLIDS INSOLUBLE IN A PRESELECTED FLUID AND OF A CARRIER FLUID MIXED WITH SOLUBLE PARTICLEFORM SOLIDS SOLUBLE IN SAID PRESELECTED FLUID, AT LEAST TWO OF EACH OF SAID SLUGS BEING SO INJECTED, SAID DISCRETE SLUGS BEING INJECTED AT A PRESSURE SUFFICIENT TO HOLD SAID FRACTURE OPEN WIDE ENOUGH TO PERMIT SAID SLUG TO ENTER SAID FRACTURE, THE CONCENTRATION OF SOLIDS IN THE CARRIER FLUID OF EACH OF SAID DISCRETE SLUGS BEING IN AN AMOUNT SUFFICIENT TO FORM A DISCRETE LAYER OF SOLIDS PARTICLES OF PRESELECTED THICKNESS WHEN DEPOSITED IN SAID FRACTURE WHEREBY A PLURALITY OF THIN ALTERNATE LAYERS OF SAID INSOLUBLE SOLIDS AND SAID SOLUBLE SOLIDS ARE DEPOSITED IN SAID FRACTURE, SAID INSOLUBLE SOLIDS AND SAID SOLUBLE SOLIDS HAVING A DENSITY GREATER THAN THE DENSITY OF THE CARRIER FLUID WITH WHICH THEY ARE MIXED, CEASING INJECTION OF SAID CARRIER FLUIDS INTO SAID FRACTURE THEREBY RELEASING THE PRESSURE HOLDING SAID FRACTURE OPEN, AND PERMITTING SAID SOLUBLE SOLIDS TO BE DISSOLVED WITH SAID PRESELECTED FLUID WHEREBY SAID FRACTURE REMAINS PROPPED OPEN BY HORIZONTALLY DISPOSED BRIDGES OF SAID INSOLUBLE SOLIDS HAVING VOID SPACED BETWEEN SAID BRIDGES.

Claim 2

A METHOD FOR INCREASING THE PERMEABILITY TO FLUIDS OF A SUBSTANCE EARTH FORMATION HAVING AT LEAST ONE VERTICALLY ORIENTED FRACTURE EXTENDING FROM THE WALL OF THE WELL BORE INTO SAID INFORMATION COMPRISING SUCCESSIVELY INJECTING INTO SAID WELL BORE AND THENCE INTO SAID FRACTURE ALTERNATE DISCRETE SLUGS OF A CARRIER FLUID MIXED WITH INSOLUBLE PARTICLE-FROM SOLIDS INSOLUBLE IN A PRESELECTED FLUID AND OF A CARRIER FLUID MIXED WITH SOLUBLE PARTICLEFORM SOLIDS SOLUBLE IN SAID PRESELECTED FLUID, AT LEAST TWO OF EACH OF SAID SLUGS BEING SO INJECTED, SAID DISCRETE SLUGS BEING INJECTED AT A PRESSURE SUFFICIENT TO HOLD SAID FRACTURE OPEN WIDE ENOUGH TO PERMIT SAID SLUG TO ENTER SAID FRACTURE, THE CONCENTRATION OF SOLIDS IN THE CARRIER FLUID OF EACH OF SAID DISCRETE SLUGS BEING IN AN AMOUNT SUFFICIENT TO FORM A DISCRETE LAYER OF SOLIDS PARTICLES OF PRESELECTED THICKNESS WHEN DEPOSITED IN SAID FRACTURE WHEREBY A PLURALITY OF THIN ALTERNATE LAYERS OF SAID INSOLUBLE SOLIDS AND SAID SOLUBLE SOLIDS ARE DEPOSITED IN SAID FRACTURE, SAID INSOLUBLE SOLIDS AND SAID SOLUBLE SOLIDS HAVING A DENSITY GREATER THAN THE DENSITY OF THE CARRIER FLUID WITH WHICH THEY ARE MIXED, CEASING INJECTION OF SAID CARRIER FLUIDS INTO SAID FRACTURE THEREBY RELEASING THE PRESSURE HOLDING SAID FRACTURE OPEN, AND PERMITTING SAID SOLUBLE SOLIDS TO BE DISSOLVED WITH SAID PRESELECTED FLUID WHEREBY SAID FRACTURE REMAINS PROPPED OPEN BY HORIZONTALLY DISPOSED BRIDGES OF SAID INSOLUBLE SOLIDS HAVING VOID SPACED BETWEEN SAID BRIDGES.