Tackling Watercut History Matching Challenges for Proximal Wells- A Niger Delta Case Study

Abstract

This paper reviews a history matching case study of a reservoir with two oil producers located proximally in the same reservoir, with a slight vertical offset. This proved challenging to match due to the significant difference in the water production trends. This study highlights the methodology taken during the history matching process to identify the key element(s) responsible for the marked difference in water cut trends. The objective of this paper is to share steps taken in identifying the variables responsible for the observed behavior and showcase the results of key tests on variables in the reservoir during the history matching process. Details of the investigative process undertaken to identify the defining variable/element impacting the water production performance will be shared with lessons learned from the process itemized. The history match efforts revealed that the difference in water production signatures seen from both wells close to each other was because of the contrast in reservoir static properties which occur between the wells. This prompted a revisit of the seismic data for the region, which corroborated the updated reservoir understanding. Following these learnings, the history match project was completed and resulted in the optimal placement of a new development producer well. Initial production results from the new development well matches closely to the model forecasts, further validating the model parameters and stratigraphic inferences. A key lesson learned from this project is that localized history matching difficulty is best tackled by first reviewing drilling and completion data for the area of interest, the initial test data and a revisit of the stratigraphic concept use in the earth modelling phase of the project. As a best practice, thorough investigation of stratigraphic concepts for the reservoir alongside analog reservoirs will help in a more accurate first-time description for the reservoir.