A Method for Matching Unconventional Wells and Reservoirs Based on Semi-Analytic Models

Abstract

Unconventional well technology is often used as one of the most important means to reduce costs and increase efficiency in oil fields. There are many methods for unconventional well type optimization, but there are relatively few studies on whether the well type is suitable for the reservoir. In this paper, a method for matching unconventional wells and reservoirs is established. In our method, we first simplify the reservoir and choose initial suitable well types based on experience and then use a semi-analytical model to calculate the production rate in different producing sections. After that, we define some parameters to evaluate the matching degree of well types and reservoirs. Finally, we determine whether these well types are suitable for the reservoir based on these parameters. At the end of the paper, we apply the method to a specific case. The result shows that a stepped well is suitable for exploiting thin interbed reservoirs, but it is necessary that the permeability and fluid viscosity in different layers are within a certain range, and the shape of the stepped well is also limited. This paper gives a specific value for this range and limitation. The method for matching unconventional wells and reservoirs proposed in this paper is helpful for guiding the selection of unconventional well types before drilling.