Understanding the Roles of Inflow-Control Devices in Optimizing Horizontal-Well Performance

Abstract

Inflow Control Device, often referred to as equalizer, is a completion hardware that is deployed as a part of well completions aimed at distributing the inflow evenly. Even though the detail structures vary from one design to another, the principle for different inflow control devices is the same -restrict flow by creating additional pressure drop, and therefore balancing or equalizing wellbore pressure drop to achieve an evenly distributed flow profile along a horizontal well. With a more evenly distributed flow profile, one can reduce water or gas coning, sand production and solve other drawdown related production problems. In general, inflow control devices are not adjustable; once installed in the well, the location of the device and the relationship between rate and pressure drop are fixed. This makes the design of a well completion and inflow control devices extremely critical for production. Inflow control devices can be either beneficial or detrimental to production, strongly depending on the reservoir condition, well structure and completion design. Realizing that reservoir conditions will change during the life of a well, the impact of an inflow control device is a function of time. The inflow control devices sometimes can be overlooked if the design is only based on reservoir flow simulation.In this paper, we will investigate how and when an inflow control device should be used. An integrated analysis method of inflow (reservoir) and outflow (wellbore) is used to generate the flow profile of a horizontal well, and additional frictional pressure drop created by inflow control devices will be considered. Two conditions that result in production problems, wellbore pressure drop and breakthrough of unwanted fluids, will be addressed. The focus will be on when and how an inflow control device can optimize production. Examples at field conditions will be used to illustrate that it is critical to understand the reservoir conditions and wellbore dynamics together when designing a well completion with inflow control devices. Since uncertainty of reservoir condition always exists, backup plans and conservative designs are desirable. The observations from this study show that overdesigned inflow control devices will not just increase the cost of well completion, but also impact the well performance negatively.

Computational Study of Heavy Oil Production with Inflow Control Devices

“…Further investigations revealed that this was due to the heel-toe effect (Daneshy, 2010). Different types of Inflow Control Devices are developed to delay early breakthrough by restricting the flow (Fernandes, 2009, Al-Khelaiwi, 2007. ICDs are designed to give a more uniform oil production along the horizontal well.…”

Near well simulations of heavy oil production with ICD completion

“…In this study, changes in reservoirs permeability are the matter of concern in terms of reservoir heterogeneity. Permeability difference is more likely to appear in long reservoirs, therefore, leading to non-uniform pressure distribution through the well and early water or gas breakthrough [3].…”

“…The economical situation all around the world and the high availability of heavy oil recourses are the two main reasons which make these resources more valuable than ever before [1]. Horizontal drilling have been developed and utilized successfully during the past decades which enables more efficient production from long thin oil deposits by enhancing reservoir contact and thereby optimizing well performance [2][3][4][5]. However, there are still challenges regarding early water or gas breakthrough due to the frictional pressure drop along the well, reservoir heterogeneity and annular flow which impacts the production.…”

“…different driving force from one to another location of the well in horizontal direction). In addition to heel-toe effect, reservoir heterogeneity and annular flow are also limiting the oil recovery [2][3][4][5]. Inflow Control Devices (ICDs) have been developed and introduced by Norsk Hydro since early 1990s [2].…”

“…ICDs are passive Inflow Control Devices with the main function of equalizing the flow from heel to toe part of the well. With the application of ICDs water and gas breakthrough are delayed for a longer duration and annular flow is decreased [2][3][4][5]. However, due to ICDs prefixed installation and dynamic conditions of the reservoir, pressure profile through the well changes with time and therefore leading to early water or gas breakthrough.…”