Patent ID: 7946344

Claim:
A method of producing oil and/or gas through a well traversing stacked oil and/or gas bearing earth layers, the method comprising: assessing locations along the length of the well where the well path traverses said stacked oil and/or gas bearing earth layers; mounting a plurality of expandable packers and integrated perforating gun and sandscreen assemblies on a production tubing such that when the production tubing is installed within the well each integrated perforating gun and sandscreen assembly is located adjacent an oil and/or gas bearing earth layer and at least one expandable packer is located between each pair of adjacent oil and/or gas bearing earth layers; providing the production tubing with at least one inflow opening adjacent to each sandscreen assembly; installing the production tubing within the well such that each integrated perforating gun and sandscreen assembly is located adjacent an oil and/or gas bearing earth layer and at least one expandable packer is located between each pair of adjacent oil and/or gas bearing earth layers; inducing each expandable packer to expand and provide an annular seal between the outer surface of the tubing and the inner surface of the wellbore or wellbore casing; firing the perforation gun assemblies such that each perforating gun assembly shoots a perforation into the wellbore casing and/or surrounding oil and/or gas bearing layer; and producing oil and/or gas by inducing oil and/or gas to flow from each oil and/or gas bearing layer via the perforations through the sandscreen assemblies and inflow openings into the interior of the production tubing, wherein at least one sandscreen assembly is substantially tubular and is penetrated by at least one perforating gun comprising an explosive charge that is arranged within a cup shaped gun shroud with a bottom that is secured to the production tubing, a tubular side wall that extends through an opening in the tubular sandscreen assembly and a firing mouth that is arranged in an annular space between the outer surface of the tubular sandscreen and an inner wall of the well or of a well casing or well liner.