Modeling transient flow behavior of eccentric horizontal well in bi-zonal formation

Abstract

In this study, an eccentric horizontal well in a bi-zonal formation and traversing the inner zone is first modeled. Three novel conceptual models are presented for three different well-placement situations: a horizontal well (i) in an inner zone, (ii) traversing partially in an inner zone, and (iii) traversing fully in an inner zone. A point source model in a bi-zonal formation is established and solved using the Laplace transform, finite Fourier cosine transform and separation of variables. The pressure solutions for a point source in the inner and outer zones are obtained by integrating the point-source solution along a horizontal well. A series of type curves is simulated to reveal the transient flow behavior of a horizontal well in a bi-zonal formation. The main flow regimes are discerned based on the type curves. Eight, six, and six flow regimes were discerned for the first, second, and third situations, respectively. The effect of different deviated distances on the type curves was analyzed. The type curves are compared among the three situations. Finally, the model is applied to a real case to validate it. This study can provide insights into the transient flow behavior controlled by an eccentric horizontal well in a bi-zonal formation.