Comparison of 20 Minnelusa Waterfloods in the Powder River Basin

摘要

Tis study compares the oil produced at a projected pore volume (PV) produced predicted from a suitable curve fit. The study compares fresh waterfloods with brine floods. The data plots and curve fitting techniques are such that PV Oil produced could be chosen for the Y axis for easier economic analysis. This technique was developed and described in Griffith. The study was originated from interest generated by work performed by Morrow's research group at the University of Wyoming, (see Tang~(26), and Tang and Morrow~(27)), indicating that fresh water flooding could result in a greater oil recovery then saline floods. Table 1 and Figure 1 shows the comparison of our 20 chosen waterfloods. The Widge field, which extends above the top of the chart, has not produced sufficient water to define the waterflood. The lowest plotted field, the Spirit Field, appears to have watered out very quickly after initialization of the waterflood. Figures 2 and 3 are the 20 flood separated into non-enhanced and enhanced floods. The West Semlek waterflood is placed in the non-enhanced although an attempt had been made to use polymer in the field. We have assigned fresh water flood status to those fields initially flooded with Fox Hills water even though the later makeup water was combined with produced brines. The West Semlek, the one brine flood, is the flood in Figure 1 which has the x marker and intercepts the 2.0 pore volumes fluid (water plus oil) produced at 42percent of OOIP produced. In general the fresh water floods had generally higher recoveries than the one brine flood, which is consistent with Morrow's laboratory results.