Petroleum Production Systems

Chapter 2. Production from Undersaturated Oil Reservoirs

2.1. Introduction

Well deliverability analysis predicts the wellbore flowing pressure for a given surface flowrate. Chapters 2–5 deal with well inflow performance and describe the reservoir variables that control well productivity under different conditions. Wells drilled in oil reservoirs drain a porous medium of porosity ϕ, net thickness h, and permeability k. To understand the process of flow from the reservoir and into the well sandface, a simple expression of Darcy’s (1856) law in radial coordinates can be used first:

where A is radial flow area at a distance r given by A = 2πrh.