TORP Continues to Analyze Gel Polymer Treatments in Kansas
Gel polymer treatments are usually performed when water production becomes a growing concern for operators. For instance, the Arbuckle reservoirs are typically visualized as an oil column on top of a strong aquifer causing high water production. Therefore, a large number of gel polymer treatments have been applied with the objective to improve reservoir sweep efficiency. A discounted cashflow analysis was conducted for fifty-nine wells in which production wells were treated with chrome acetate-polyacrylamide gelant to reduce water production and increase oil production. The objective of this analysis was to evaluate the economic value of the treatments.
Individual well economics vary from well to well depending on polymer volume, post treatment oil and water production rates, disposal cost, electrical or artificial lift equipment costs, and chemical treatment costs.
These economic parameters were estimated as an averaged rate, and are presented in Table 1 . Operating cost was based on $1400 per well per month, and assuming a total production of 800 barrels of fluid per day results in the operating cost of $0.06 per barrel. Disposal cost was based on the current surface water handling and discharge cost of $0.05 per barrel. No inflation factors or changes in chemical treatment costs were included in this analysis. The discount rate used in the analysis was 10% and the oil price was held constant at $22 per barrel, the approximate price at the time most of the wells were treated.
Table 1 - Estimated Actual Costs
|Water Disposal charge per barrel||
|Treatment cost per barrel of polymer pumped||
|Lifting cost per barrel of fluid produced||
|Oil price per barrel at time of treatment||
The economic analysis was performed for a period of one-year post treatment. The economics for each well were analyzed separately on a monthly basis. On a number of wells production data was available for only six months or less post treatment. In those cases a decline curve analysis was used to predict production rates for a 12 months period. For oil, the production rate was predicted to a one-year post treatment with an exponential type curve. The water production curve was extended linearly to the time of one-year.
A frequency plot was made based on the analysis and is shown in Figure 1. This bar graph plots the number of wells that had the net present value (NPV) shown on the baseline of the bar graph. As shown, 49 of the 59 wells studied had a positive NPV and about one half had a NPV of $40,000 or more. This represents a very positive success rate for the treatment process.
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Last Modified March 2005