Comprehensive physical and numerical modeling of a horizontal well

Petroleum engineers have depended largely on empirical models for multiphase flow in pipelines and horizontal wells. While empirical models have been proven to be adequate in some cases (depending on flow regimes), they do not give any theoretical basis and, therefore, an extension of these models to much more complex flow, such as horizontal wells, is not justified. Despite recent advancement in horizontal well technology, little has been done in the areas of physical and mathematical modeling of horizontal wellbore itself. No study has been reported on three-phase (water-oil-gas) flow or gas-liquid flow when the liquid phases show emulsification of oil and water. This paper addresses the problem of both physical and mathematical modeling of horizontal wellbores. Experimental results gave insight into the type of flow occurring in a horizontal wellbore. This observation was used in developing a comprehensive mathematical model of the horizontal wellbore. Finally, the wellbore model is coupled with a reservoir simulator and a series of numerical tests is performed to study the effect of pressure drop in the wellbore on the performance of a horizontal well. The usefulness of this new modeling technique is pointed out vis a vis conventional modeling techniques.