Optical sensor use in alternate path gravel packing with integral zonal isolation

A production string assembly for producing hydrocarbon fluid from a wellbore comprising:

• a running portion;
• a production portion secured to the running portion and having:
• a plurality of production nipples in secured relation within the production portion for placement proximate a plurality of production zones within the wellbore, the production nipples having openings for drawing of production fluid inwardly from the surrounding wellbore;
• a plurality of packer assemblies for selectively forming a fluid seal within an annulus of the wellbore, the packer assemblies being incorporated within the running portion to isolate the production nipples from one another, at least one packer assembly having:
• a) a central tubular mandrel defining a flowbore to contain hydrostatic pressure;
• b) a packer element carried by the central mandrel, the packer element being moveable between an unset position and an axially compressed set position;
• c) a setting mechanism radially surrounding the central mandrel for moving the packer element to its set position in response to hydrostatic pressure within the flowbore;
• a wellbore condition sensor assembly having a monitor device and a linear sensor cable disposed generally upon the radial exterior of the production nipples and being disposed axially through at least one of the packer assemblies;
• and
• a feed-through path defined axially through at least one central mandrel of the at least one packer assembly, the feed-through oath retaining the sensor cable in isolation from external fluid pressures.

A method of producing hydrocarbon fluids from a wellbore having multiple production zones therein while monitoring a wellbore condition of said wellbore, the method comprising the steps of:

• a) disposing a production string assembly into the wellbore, the production string assembly defining an axial flowbore therewithin and having:
• a production nipple for each production zone to be produced, the production nipple being perforated to allow entry of production fluid from a production zone into the flowbore;
• at least one packer assembly for isolating each production nipple from a neighboring production nipple, the at least one packer assembly having:
• a central tubular mandrel defining a flowbore to contain hydrostatic pressure;
• a packer element carried by the central mandrel, the packer element being moveable between an unset position and an axially compressed set position;
• a setting mechanism radially surrounding the central mandrel for moving the packet element to its set position in response to hydrostatic pressure within the flowbore;
• a wellbore condition sensor assembly having a monitor device and a linear sensor cable disposed generally upon the radial exterior of the production string assembly, the sensor cable further being disposed axially through the central mandrel of the at least one packer assembly;
• b) gravel packing within the wellbore around the production nipples;
• c) setting the packer assemblies;
• and
• d) using the wellbore condition sensor assembly to monitor at least one wellbore condition proximate each production zone to be produced.