Jim Pazos

The Uintah Basin, is a physiographic section of the larger Colorado Plateaus province, which in turn is part of the larger Intermontane Plateaus physiographic division. It is also a geologic structural basin in eastern Utah, east of the Wasatch Mountains and south of the Uinta Mountains. Drilling in the Uteland Butte formation in N.E. Utah, you can experience an unusual problem. It is known for its "Black Wax" & " Yellow Wax " paraffin, which is the objective hydrocarbon that is produced. Paraffin will go into liquid form that, while using an Oil based mud, goes into solution & causes funnel viscosity & gel strength to climb extremely high. The best solution when using an OBM has been to dilute it back with diesel. Because of this problem paraffin causes OBM, most found a better solution is to use of a specialty WBM which is sometimes referred to as a SAGD fluid (Steam Assisted Gravity Drainage). Highly inhibitive cationic mud prevents accretion of bitumen on tubular's while preventing swelling of clay It's the Green River Formation through the Uteland Butte (the pay target) that we drill here. We drill the vertical with WBM. From 8000'-9000' TVD drill the lateral with OBM, for an additional approximately 10000' – 12,000' MD more. In the laterals we use OBM's. In hopes to find an answer to the problem of paraffin contamination of OBM, I field tested using a store purchased Fabric Softener, which is an anionic Surfactant. The brand used was Downey Ultra. Keep in mind that this was FIELD experiments. Taken from a sample of one, 200 barrel batch of paraffin contaminated OBM & it had already been diluted back with diesel. I was not around for it so I dont have details on particulars. My understanding is during contamination, gels were +200 and even this diluted back batch, still had rather high gel strengths. Do to my equipment limitations, measurements where +/-while pilot testing, so possibly 5% or so could be off on my estimated barrel sample (ie +/-350 ml)