Material balance analysis is a proven technique for quantifying reservoir performance. Reliable material balance analysis requires accurate pressure and production data amongst other things. In cases where complete production data is not readily available, estimating reservoir performance properties such as pressure and fluid contacts which is needed to support further field development can be a serious challenge. This paper shows how the issue of scarcity of production data can be managed to enable proper reservoir analysis to support further field development. The paper focuses on a case study on the Ibaba reservoir where paucity of production data is a key uncertainty. The Ibaba reservoir is a Niger Delta reservoir with two parts, Part A and Part B. Both parts have been produced simultaneously from the field for over 40 years. There is a need to carry out material balance analysis on the reservoir to estimate the current fluid contacts to support Short Term Oil Generation activities (STOG). This exercise required production data from inception to the current year 2016. However, for the wells produced in Part B of the reservoir, complete production data was not readily available. To solve this problem, complete production data was generated by performing decline curve analysis on the available production data. A robustness check was carried out and this gives confidence in the results obtained.