The Reserve Growth Model of Oil Fields in the Bohai Bay Basin, China
Liu, Chenglin; Wang, Zhiqiang
Reserve growth is the increase in successive estimates of recoverable crude oil, natural gas, and natural gas liquids in discovered accumulations. With the increase of exploration maturities, reserve growth is becoming a more and more important part of petroleum resources for global basins. The U.S. Geological Survey has been studying on reserve growth models of American and international basins during these years and developing several reserve growth forecast methods. Up to now, no reserve growth researches have been done on Chinese basins and it is not clear how much reserve growth accounts for in total petroleum resources of China. This research chose the Bohai Bay basin, the largest oil resources basin in China, as the case study of oil reserve growth for Chinese basins.
Based on statistics of geological parameters and oil reserves of oil fields in the Bohai Bay basin, this study quantitatively analyzed the influences of three main factors, e.g. geographic location, field size and oil gravity, on reserve growth. The modified Arrington method and group growth method were adopted for the model development. The first significant reserve reporting year, replacing of the discovery year for the U.S. Geological Survey, was used as the effective discovery year for reserve growth of oil fields in the Bohai Bay basin.
Of 278 oil fields in the basin, 168 fields were chosen to develop the model using the modified Arrington method and 121 fields were chosen to develop the model using the group growth method. The results showed that the cumulative growth factor (CGF) calculated by these two methods were respectively 2.44 and 2.41 in the period of 37 years after the first significant reserve reporting year in the Bohai Bay basin. Reserve growth for global basins over a 25-year period either from time of discovery or from year of first production could be classified into four models, e.g. the slow (CGF less than 1.5), low-speed (CGF being 1.5-2.5), medium-speed (CGF being 2.5-5) and high-speed (CGF more than 5) growth models in light of their cumulative growth factors. The low-speed growth model fits for the oil fields in the Bohai Bay basin.
AAPG Search and Discovery Article #90163©2013AAPG 2013 Annual Convention and Exhibition, Pittsburgh, Pennsylvania, May 19-22, 2013