Experimental and Theoretical Investigations of Flow in a Horizontal Wellbore.

Abstract

Flow in horizontal wells and interaction of the flow with the reservoir were investigated experimentally and theoretically. The behavior of flow was recognized as one of highly important problems in petroleum engineering. A new test facility was designed and constructed, suitable for acquiring data on the relationship between the pressure drop and liquid holdup along the well and fluid influx from the reservoir. The proposed model AWHOZACC, calculating pressure affected by acceleration (accelerational pressure drop) as well as that of friction (frictional pressure drop) in the horizontal wellbore, showed superior performance on the basis of experimental data. AWHOZACC is based on 1D two-fluid model techniques and on the knowledge of fluid dynamics in condition of confluence. The relative magnitude of accelerational pressure drop was evaluated to find out under what conditions it was important in a horizontal well configuration. A sensitivity analysis demonstrated that the overall performance of the proposed model POPHOZN, which coupled the wellbore hydraulics to the reservoir flow through the inflow-performance-relationship (IPR) approach, successfully simulated the interaction between the homogeneous reservoir at undersaturated conditions and the horizontal well, and fluid dynamics in horizontal wells. POPHOZN serves as an analytical tool to discuss key parameters, which affect steady-state production behavior of horizontal wells, such as reservoir permeability and length of horizontal section, simply and on physical basis.