oa Horizontal Well Modeling in Complex Reservoir with Uncertainties Assessment

Horizontal wells application in heterogeneous reservoirs is challenging as implies high expenditures in conditions of difficulties with such wells modeling. In case of complex reservoir the model matched to history data and accepted to be rather accurate can give the erroneous estimation of horizontal wells performance. This paper is aimed to study the issue with using of integrated approach. As a possible reason of the mistaken forecast the uncertainties related to reservoir complexity are investigated. At first, by means of analytical solutions the uncertain parameters influencing horizontal well performance are identified. Then the qualitative analysis of their impact on the oil rate as a decision criterion is performed on the model. After that basing on the field data, the ranges of uncertainty are determined and incorporated into simulation process. Finally, by Monte Carlo technique with automatic history matching applied to the model its non-uniqueness is demonstrated proving the necessity of performing multivariant forecast that is especially critical for horizontal wells. As a result the modelling procedure is proposed and the complex of research is recommended in order to increase model reliability. This will allow uncertainties management and proper decision making in terms of projects profitability.