|
||
|
Uncertainty analysis of reserves of fluvial reservoir calculated by geological model
Reservoir Evaluation and Development
2018, 8 (4):
1-5.
DOI:
The reserves of the geological model in the offshore fluvial reservoirs are influenced by the uncertain parameters, such as the structure, plane variogram, correlation between reservoir properties and seismic attributes, irreducible water saturation, lower limiting value of effective reservoir, volume coefficient, and oil-water interface. The root that causes these uncertain parameters is analyzed. Meanwhile, taking oilfield-Q in Bohai bay as an example, and by the integrated application of the Monte-Carlo method and stochastic modeling, the effects of the uncertainty parameters on the reserves are estimated quantitatively. The probability cumulative distribution curves of reserves and 3 probability reserve value which are the pessimistic reserves（P90）, expected reserves（P50） and optimistic reserves（P10） are obtained to predict the risk and potential of the reserves. 
Fig. 4
Cumulative probability distribution of reserves
Extracts from the Article
将6个不确定性变量进行实验设计,得到9个排列来代表所有可能的分布,并建立这9个排列的地质模型,计算每个模型对应的储量。应用数理统计学假设检验的方法对6个不确定性变量的3个水平（-1,0,1）的实验结果进行敏感性分析,得到每个不确定性变量对储量的敏感性排列图（图3）,通过Monte-Carlo方法计算得到储量概率累积分布图（图4）。由图3可以看出,对储量影响较大的不确定性变量依次为油水界面、束缚水饱和度、变差函数和体积系数,其它两个变量对储量的影响较小。由图4可以看出,概率储量P90为1.12×108 m3,P50为1.19×108 m3,P10为1.27×108 m3。即该油田10个砂体的地质储量小于1.12×108 m3的可能性只有10 %,大于1.27×108 m3的可能性也只有10 %,最有可能的地质储量为1.19×108 m3,因此提供给油藏进行数值模拟的地质模型为1、9、7（或6）。3个概率储量之间的差距较小,说明在油田开发的中后期,储层储量存在的不确定性风险较小,但仍有一定的潜力可以挖掘。
Other Images/Table from this Article
|
