Well completions in weakly consolidated formations

A method for producing formation fluids from a weakly consolidated zone in a subterranean earth formation, said zone having a cohesive strength less than about 2000 psi, comprising the steps of:

• extending a production well into said zone;
• initiating production of a solids laden fluid mixture from said zone into and through said well at a rate which will generate a cavity in said zone in the near wellbore region;
• and
• continuing the production of fluid from said zone at a rate which will cause said cavity to grow until a facial area defining said cavity is sufficiently great that the fluid flow rate across said face is at a velocity less than the particle transport velocity of particulate solids in said zone.

A method for recovering hydrocarbon liquid from an earth formation zone comprising a mixture of said hydrocarbon liquid and solids particulates having a cohesive strength less than about 500 psi, comprising the steps of:

• extending a well into said formation zone having a wellbore portion in communication with said formation zone;
• determining the effective radius of said formation zone which will drain hydrocarbon liquid into said wellbore, the formation permeability in said zone, the thickness of said zone, the viscosity of said hydrocarbon liquid in said zone and the nominal pressure in said zone within said radius;
• initiating production of a solids laden fluid mixture from said zone through said well to create a cavity in the near region of said wellbore while monitoring the pressure in said wellbore and the flow rate of said solids laden fluid mixture;
• and
• controlling the flow rate of said solids laden fluid mixture from said zone into and through said well to generate a cavity in said zone having a radius which defines a cavity face of sufficient size that the fluid flow rate across said face is at a velocity less than the transport velocity of solids in said zone in said hydrocarbon liquid.