Analysis of fluid loss data II: Models for dynamic fluid loss

Fluid loss during fracturing limits the efficiency of the process. Modeling of fluid loss is important for prefrac design and postfrac analysis. The fluid-loss process is complex and difficult to accurately model theoretically because many of the parameters are difficult or impossible to evaluate. This has led to the use of empirical and semi-empirical models some of which work better than others. Testing protocols also influence the quality of the data on which these models are based. In this paper, we review some of the currently used models and propose two different models that provide better fits to the available data than currently existing models. We also discuss the influence of core length on the experimental data and modeling of this data.