Prudhoe Bay production decline

Oct. 23, 2000
Thomas Standing's article in (OGJ, Oct. 2, 2000, p. 86) describing oil production decline and expected ultimate recovery at Prudhoe Bay was thought provoking and well written but it was in part, I believe, misleading.

Thomas Standing's article in (OGJ, Oct. 2, 2000, p. 86) describing oil production decline and expected ultimate recovery at Prudhoe Bay was thought provoking and well written but it was in part, I believe, misleading. The author describes past well performance and predicts future field production rates based on historical well-test information. It is my understanding that this well-test information does not include NGL recovery from the produced gas stream, which is significant at Prudhoe Bay, and may not include all the condensate production either.

While this oversight does not influence historical "black oil" production or historical allocated oil volumes among the wells, it does very much influence predictions of ultimate recovery of hydrocarbon liquids from the reservoir and end of economic field life calculations.

NGL and condensate production has been and will continue be an important aspect of total hydrocarbon liquid production from the pool.

With respect to the author's forecast of future reservoir performance, I think the common Wall Street phrase has it covered, "Past performance is no guarantee of future returns." The author forecasts annual production of between 50 and 75 million bbl of black oil for the year 2010. Our most recent information shows that hydrocarbon liquid production for that same year will be between 70 and 105 million bbl plus an addition 20 million bbl or so of NGL.

We fully expect ultimate recovery of hydrocarbon liquids from the Prudhoe Bay reservoir to reach (and likely surpass) 13 billion bbl and the field to produce well beyond the year 2020. Recent resolution of several difficult commercial issues between the working interest owners in the unit means that activity levels in the field are picking up and there are several new projects either under way or soon to be under way. Predicting long-term production rates in a geologically and commercially complex field like Prudhoe Bay is not easy. I congratulate the author for the work he has done. I just think he shot low.

Bill Van Dyke
Petroleum Manager
State of Alaska
Division of Oil & Gas