FORECASTING THE PERFORMANCE OF AN OIL FIELD, COMPARISON OF VARIOUS USED METHODS: THE CASE OF SHUANGHE OILFIELD, CHINA

Abstract

While being the dominant source of energy, oil has also brought affluence and power to different
societies. Energy produced from oil is fundamental to all parts of society. In the foreseeable future,
the majority of energy will still come from oil production. Consequently, reliable methods for
forecasting that production are crucial. Petroleum engineers have searched for simple but reliable
way to predict oil production for a long time. Many methods have been developed in the latest
decades and one common practice is decline curve analysis. Prediction of future production of
petroleum wells is important for cost-effective operations of the petroleum industry. This work
presents a comparative analysis of methods used to predict the performance of Shuanghe oilfield,
China. Using decline curve analysis including three different methods: Arps empirical methods,
LL-model and simplified model and the new simplified model, LLModel, to crosscheck Arps
exponential decline model prediction results. The results showed by the comparative analysis of
predictions calculated proved LL-model to be the best predictor for Shuanghe oilfield since it takes
into account more parameters than the old models used in this work. However, the subsurface
information or parameters of the reservoir used in LL-model may not be available every time,
therefore Arps models may apply as defined. In Shuanghe oilfield calculated average geological
reserves N was estimated at 9449.41 ×104 tons, the average recoverable reserves NR were
estimated to 4274.61×104 tons while the water cut was 97% and the water cut predicted by LLmodel
was 96.7%; not far from water flooding curves value. The exponential decline model
showed recoverable reserves NR estimated around 4685.88×104 tons of oil while the decline phase
of total development was estimated around 34 years which means that if the actual production
conditions remain unchanged, Shuanghe oilfield would continue producing for another 25 years
from 2008.