When drilling with invert mud, diesel fuel from the invert will condense in the polyflow line in very cold weather. This eventually will block flow in the line, or at least constrict it. An added danger is actually sucking diesel into the detector. Since the bulk of condensation happens where the is a temperature change, the place to catch diesel is just downstream from the gas trap and all of its dehydrating measures. By placing a loop of larger-diameter hose in the polyflow, diesel condensing in the polyflow at the trap has a place to 'end up', allowing gas sample to pass through unimpeded. Diesel resides in only a short length of polyflow outside the trap, the rest collects in the condenser loop. The old solution was to add little loops throughout the polyflow run--which eventually meant having to string a new line, not to mention one with a bunch of little loops in it. As I keep pointing out, it doesn't have to be complicated.

A diesel condenser mounted on Jomax 3. Leave about 2 meters of polyflow between the gas trap and the loop, and put the loop in a low spot. Threaten roughneck with a dismal existance if he should mess with this arrangement. After seven days of cold weather, the loop yielded about 15 cc of diesel which would have really messed up my polyflo. Oilpatch main page Tips Menu

As added insurance, you can also place a second length of condenser hose just inside the shack to catch any diesel that might make it across the lease. A short length mounted vertically will suffice.

Insurance trap in the shack, consisting of about 12 cm of 12 mm vinyl hose. Connection is made using 7 mm ID rubber hose to attach polyflo ends to vinyl. Haywire was used for clamps, screw clamps are preferred. Be sure to mount the arrangement vertically, downstream of filter cannister (seen just above). Should a bit of diesel make it this far, that's as far as it gets.