Well packing system

A well packing structure for use in an injection well having a casing or in a gas or light oil production well having a casing, wherein said packing structure is positioned beneath ground level within at least some of the casing, wherein said structure comprises a series of zones including a formation or pay zone, and wherein the packing particles above the formation or pay zone are comprised of a maximum size diameter defined by the equation:

• ##EQU4## wherein, Dp=diameter of a spherical shaped particle (in.)
• W=weight of the well casing (lb/ft.)
• OD=outside diameter of the well casing (in.)
• th.sub.w =thickness of the casing wall (in.) wherein "a" ranges from about 0.001 to about 1.0, and wherein said series of zones above the formation or pay zone comprises a packer protection zone wherein "a" in the particle size diameter equation ranges from about 0.001 to about 0.05, and a casing quench zone wherein "a" ranges from about 0.3 to about 1.0.

A well packing structure for use in an injection well having a casing or in a gas or light oil production well having a casing, wherein said structure is positioned within at least some of the casing beneath a well packer and wherein said structure comprises a series of zones, and wherein the packing particle maximum diameter in each zone is defined by the equation:

• ##EQU5## wherein Dp=diameter of a spherical shaped particle (in.)
• W=weight of the well casing (lb/ft.)
• OD=outside diameter of the well casing (in.)
• th.sub.w =thickness of the closing wall (in.), and wherein,
• "a"=the value specified for the zones listed below:
• (a) a packer protection zone wherein "a" ranges between about 0.001 and about 0.05;
• (b) a casing quench zone wherein "a" ranges between about 0.3 and about 1.0;
• and,
• (c) a pay or formation zone wherein "a" ranges between about 0.05 and about 0.1.

A method of packing an injection well having a casing or a gas or light oil production well having a casing with particles which provide passive protection of well casing and tubulars from well fires, said method comprising:

• determining the maximum particle size diameter to be used for said packing using the equation:
• ##EQU6## wherein Dp=diameter of a spherical shaped particle (in.)
• W=weight of the well casing (lb/ft.)
• OD=outside diameter of the well casing (in.)
• th.sub.w =thickness of the casing wall (in.) and wherein "a" is at least about 0.001 and at most about 1.0;
• and,
• placing non-combustible particles, no larger than the maximum particle size determined, within at least some of the casing below ground level.