Tight gas stimulation by massive hydraulic fracturing: a study of well performance

The performance of several wells in tight gas sands, belonging to Exxon and to other operators, which have been stimulated by massive hydraulic fracturing treatments are examined and compared with the performance expected on the basis of net sand available and the fracturing treatment employed. The cleanup behavior immediately after fracturing is compared with that predicted by a cleanup simulator. Subsequent producing rates are compared with predictions from a general purpose reservoir simulator. Observed performance is found to be substantially below expectations on the basis of net sand observed at the well bore and the frac treatment employed. Several possibilities are examined to explain this discrepancy. All of the treatments on fluvial lenticular sands in the Rocky Mt. Area are found to be correlatable by reducing the net sand thickness found at the well bore at a constant factor. (14 refs.)