Advanced Data Analysis from Laboratory Testing for Soft-Sand Completions

Laboratory sand retention and dynamic fluid loss/retained permeability reservoir drill-in fluid (RDIF) testing protocols are almost always run in a linear flow configuration. While these tests may provide excellent correlations and predictive curves, the most useful form of the final data would be translated into radial flow predictions for different drawdown conditions into a wellbore. An effort has been made using data from existing sand retention and dynamic fluid loss/retained permeability RDIF testing protocols to demonstrate more complete analysis of the standard data provided from the tests, including radial flow calculations. This paper provides an explanation of the test methods and data they generate, along with the laws and equations used to simplify the problem of linear-to-radial flow data. Constant drawdown sand retention testing provides gravel pack, screen, and clean formation permeability data, while Dynamic Fluid Loss/Retained Permeability RDIF testing on the unconsolidated formation material provides the final damaged screen permeability, remaining filtercake permeability, invaded formation permeability and the undamaged formation permeability. Using the combination of data from the two tests, translation from linear to radial flow calculations can be estimated for a wellbore scenario using the specific permeability measurements for each wellbore section, gathered from the original testing. Using representative wellbore data, a correlation is made between laboratory permeability measurements and flow rates and expected wellbore pressures. Step by step calculations using the Radial Flow equation, assuming steady state and single phase flow, allows a simpler conversion to more typical data seen in wellbore scenarios. Calculations have been made to simplify data from constant drawdown tests and dynamic fluid loss/retained permeability RDIF testing from linear flow in laboratory conditions to estimate radial flow for wellbore conditions. The results of this study can provide a more streamlined process to translate laboratory data from multiple tests into applicable radial flow which can be used for wellbore calculations.