ABSTRACT

The results of a joint research and field effort to develop commercial gas production from the very low permeability Muddy "J" Formation in the Wattenberg Field near Denver, Colorado, by the application of MHF (Massive Hydraulic Fracturing) are presented.

The Muddy "J" Formation is approximately 50 ft (15 m) thick and found at a depth of about 8,000 ft (2,440 m). The bottom-hole temperature in these wells is 260°F. Initial attempts to develop the gas potential in this field were made by stimulating wells with 40,000 to 50,000 gals gelled-water fracturing treatments. These efforts resulted in increased gas production; however, the rapid decline of gas production rates with time indicated that the stimulations would be economic failures.

Laboratory studies were made to evaluate various fracturing fluids and to investigate fracture flow capacity with various proppant plans. On the basis of these studies, a stimulation program was developed which utilized a polymer emulsion fracturing fluid. Treatments with up to 500,000 gals of fluid and 1,000,000 lbs of sand have been conducted. Field case-histories are discussed and the results of MHF treatments are compared with the conventional fracturing treatments.

It was found that in the better areas of the field the well and treatment payout time was inversely proportional to the treatment size, showing that the larger treatments are the more desirable. In the poorest areas of the field, well and treatment payout is indefinite at the current interstate gas price.