Review: The Hall Plot Method Update, April 2000

The Hall Plot Document (Rev. 0) Review of the first version - an update (Rev. 1) will be soon on the web page Contents: The Hall plot theory Practical applications of the Hall plot method Early detection of slope changes Also: The role of Hall plot and other continuous monitoring techniques in the overall well monitoring strategy

The Hall Plot Method Description of the basic theory Practical aspects: examples of applications to real field data Advantages versus disadvantages Limitations and potential pitfalls, such as the importance of: reservoir pressure and correct bottom hole pressure correlation

The Hall Plot Method Cumulative time - pressure multiple versus cumulative injection fluid volume Theoretically, the (modified) Hall slope has a quantitative meaning (RII) but practically it has qualitative meaning

The Hall Plot Method The core behind the Hall plot method is that it takes readily available data, and minimises fluctuations due to “noise” The Hall plot technique is best known for well history overview Also possible to use for more specific analysis, given that constraints are taken into account, such as steady state etc. Early detection of slow gradual changes in slope (e.g. plugging, or flow geometry changes)

Continuous Injection Monitoring These method include: Pressure and rate versus time Injectivity and reciprocal injectivity indices Hall plots, etc. Analysis of readily available data (pressure and rate) can give a strong early indication of changes in the injection behaviour However, this analysis of often not exclusive and to explain certain behaviour, specific tests need to be performed

Continuous Injection Monitoring and Well Monitoring Strategy Guidelines and best practices needed