Finn Patrick Nilsen

Inflow Predictions and Testing While Underbalanced Drilling

With increased interest in underbalanced drilling, including coiled tubing drilling, the importance of realistic inflow predictions and the potential for formation evaluation based on rate measurements is also receiving increased attention. This paper addresses these points by introducing new models for inflow predictions at various levels of complexity and accuracy for spreadsheet and calculator applications. The methods can handle both homogeneous and layered reservoirs, and essentially traps the expected formation response within a narrow range based on drilling speed and the ratio of vertical to horizontal permeability.

A new method for determining droplet size distribution of an unstable dispersion

Abstract The droplet size distribution (DSD) of unstable water/oil dispersions has been studied with a new technique. The technique is based on a fast dilution of the dispersion injected into an analysis vessel where the DSD is analyzed with a video camera and a image analyzing tool. Dispersions generated with no pressure drop in the flow rig were compared to those generated with a pressure drop over a needle valve. The latter dispersion showed a much narrower DSD and a lower average droplet diameter. The results are from preliminary experiments in order to evaluate the method.