Performance of Inflow Control Devices (ICDs) in Horizontal Injection Wells with Injection Induced Fractures

Abstract

Abstract Inflow Control Devices (ICDs) have been extensively used in injection wells to control the injection profile. The design of ICDs is usually based on the permeability and thickness of each injection zone. The primary objectives of this paper are to (a) study the influence of ICDs on the initiation and propagation of injection induced fractures (IIFs), (b) to demonstrate the importance of injection induced fractures on the design and placement of ICDs in horizontal injectors. A fully coupled reservoir-fracture-wellbore simulator is applied to study the performance of injectors with ICDs. The simulator implicitly couples the performance of the ICDs with multi-phase flow in the reservoir, solid mechanics, thermal effects and allows for fracture propagation and particle plugging. The stress field in the reservoir accounts for thermo-poro-elastic effects during cold water injection. Fracture initiation and propagation induced by both internal and external filtration and thermal effects are simulated. The ICD pressure drop is implicitly solved in the fully coupled non-linear system of equations using a Newton-Raphson method. This allows us to predict fracture initiation and growth in different sections of the well over time. The impact of ICD placement and characteristics can be clearly evaluated by the model. It is shown that the growth of injection induced fractures plays a dominant role in the performance of the ICDs and controls the injection flow profile. The flow distribution without ICDs can vary significantly with time due to injection induced fracture growth. Injector performance is evaluated for different ICD arrangements. The ICDs are shown to effectively control the flow distribution along the wellbore for better conformance control. If properly designed, ICDs can help to minimize the impact of potential "thief" fractured zones. While ICDs reduce injectivity by creating an additional pressure drop, the flow is much more evenly distributed, and this can help to slow down the injectivity decline, improve reservoir sweep and oil recovery. The results show that, in most cases, more ICDs and specific ICD arrangements can improve the injection profile to increase the recovery and decrease the risk of out zone fracture growth. This paper presents a method to study the influence of ICDs and injection induced fractures on water injector performance using a fully coupled reservoir-fracture-wellbore model. The model, for the first time, presents results showing the dynamics of growth of multiple fractures in segments of the injector wellbore separated by ICDs and the impact they have on the flow distribution in the well. These results form the basis for the design and placement of ICDs in horizontal injectors.