Design, Analysis, and Diagnostics for Passive Inflow Control Devices with Openhole Packer Completions
Authors: Gavioli Paolo , Garcia Gonzalo Alberto , Serrano Juan Carlos 
Published: July 2010

Abstract
More than 12 years of field experience using reservoir-optimized completions, including passive inflow control devices (PICDs) and openhole packers in sandstone and fractured carbonate reservoirs, has led to the accumulation of best practices, guidelines, and rules of thumb to design, analyze, and diagnose these types of completions. This paper summarizes the most important issues to consider in each phase of the design and analysis of these completions.
Important design and diagnostic considerations have been generated in order to design the PICD under different fluid properties, reservoir uncertainties, and optimum operational considerations that allow for equalization of flow along the entire length of the horizontal section. These best practices came from simulation studies and, more importantly, from extensive worldwide run history and lessons learned.
No matter what the reservoir type is, the use of openhole packers for horizontal section compartmentalization offers a benefit in terms of inflow and annulus flow control. Therefore, it is important to determine the optimum number of isolation packers and the placement of packers to be used in each application. An extremely important role of compartmentalization is the ability to control gas and/or water after breakthrough occurs in highly fractured carbonates. This has been proven from analyzing a significant amount of production logs post installation.
Once the completion is in place, it is important to determine its effectiveness in order to establish potential optimization actions. Therefore, the analysis of pre- and post-job data available provides valuable information to determine the optimum operation conditions. The estimation of net benefit for this technology plays an important role and it can be determined before or after its installation. Important guidelines will be presented to quantify the added value of this technology.

Introduction
Several papers have been written so far that explained the value added by PICD in horizontal wells5,9,13, as well as papers that explained potential PICD applications (for instance: producer and injector, oil and gas, sandstone and carbonate, single lateral or multilaterals), but none have described the design, analysis, and diagnostic of this technology. The design phase plays an important role in order to obtain the benefit of this technology. The wrong selection of the right PICD for a particular application can drive to unsatisfactory results.
Two well completion options for PICD can be considered: gravel pack or open annulus. Both cases have radial and lineal flow. In the open annulus case, the fluid flow traveling in the annulus space, between open hole and outer screen, is higher than the gravel pack case. This paper would be focus on analyze the open annulus case. The gravel pack case requires additional consideration in the PICD design to guarantee that the gravel can be pumped through the PICD and therefore have a good gravel pack.
Whether the PICD completion is gravel pack or open annulus, the design is highly important to obtain the optimum flow velocity, flow rate, influx equalization, and ultimately better water control and optimum oil recovery. The main key to the PICD design is to determine the optimum amount of PICD joints, the flow resistance rating (geometry), the location, and the optimum number of compartments as well as packer type.
Those answers in the past were obtained by trial and error or field experience, or by using steady-state simulators. However, numerical simulator (transient models) have most recently been used; this method includes the well completion description to establish the optimum well completion equipment to obtain the best horizontal well performance.