In long horizontal wells, production rate is typically higher at the heel of the well than at the toe. The resulting imbalanced production profile may cause early water or gas breakthrough into the wellbore. Once coning occurs, well production may be severely decreased due to limited flow contribution from the toe. To eliminate this imbalance, inflow control devices (ICDs) are placed in each screen joint to balance the production influx profile across the entire lateral length and to compensate for permeability variation.Pressure drop in an ICD is created through either restriction or friction mechanisms. Restriction mechanisms rely on a contraction of the fluid flow path to generate an instantaneous pressure drop, resulting in higher velocities, and are thus more prone to long-term erosion damage as well as plugging during mud flowback. A restriction device, however, is less sensitive to viscosity properties of the fluid. A frictional device, which creates a pressure drop over a distributed length, is less likely to erode due to lower fluid velocities, but is more sensitive to viscosity changes. Viscosity insensitivity is desired to minimize preferential water flow whenever water breaks through into the well. This paper will detail the development of a new hybrid design concept that uses the best features of the restricting and friction designs, while minimizing the less desirable characteristics. Because these ICDs are permanent downhole components, their long-term reliability is imperative, and these new developments will improve their resistance to erosion and their ability to effectively balance inflow. Conceptual fluid dynamics analysis was used extensively to characterize the new design, along with actual full-scale flow testing.

The main horizontal well completion issues have been identified and addressed during the previous decades, resulting in wells with better performance, lower water production and higher recovery efficiencies. One of the most important issues has been inflow equalization, which is affected by reservoir heterogeneities and pressure losses in the completion (annulus and liner). Evaluations of the flow equalization, in sandstone and natural fracture reservoirs, along horizontal wells have shown the importance of this technique to improve reservoir management.Passive inflow control device (PICD) performance in producer and injector wells under different fluid properties (density and viscosity) and operational conditions will be presented to show the technical benefits of this technique as well as their improved recovery efficiencies when compared to non-PICD completions. The quantification of the benefits of this completion technique was performed using a fully integrated reservoir simulator where the PICD flow performance characteristic, well completion description (packers, blank pipe, gravel pack, annulus flow, etc.), and reservoir simulation are considered.Lessons learned and best practices regarding equipment selection and specification acquired during the last 10 years are summarized to define potential PICD applications in horizontal wells. Finally, the field experiences and numerical simulation results are analyzed to establish the best well completion strategy to fit specific reservoir conditions. SPE 124349 PICD Design CharacteristicsThe primary factor in maintaining a uniform influx is the ability of the device to resist erosion from fluid-borne particles that pass through the screen. Screens are not designed to prevent 100% blockage of all particles from the formation. During production, formation fines that are produced through the screen also pass through the PICD. These fines can and will erode a PICD over time if the fluid velocity is high enough and fines are in the flow stream. The rate of erosion will depend on the following factors: particle size, particle concentration, and fluid velocity. The first two factors are dependent on well conditions, while the third is dependent on PICD geometry and design.Currently, there are two major different types of PICD designs in the industry: orifice/nozzle-based (restrictive) and helical-channel/labyrinth pathway (frictional). They use two different methods to achieve a uniform inflow profile. The orifice-based PICD uses fluid constriction to generate a differential pressure across the device. This method essentially forces the fluid from a larger area down through small-diameter ports, creating a flow resistance. This overall change in pressure is what allows the PICD to function.The helical-channel ( Fig. 1) and labyrinth pathway PICDs, however, use surface friction to generate a similar pressure drop. The helical channel design is one or more flow channels that are wrapped around the basepipe of the screen. The labyrinth design uses a tortuous pathway to cre...

When producing long, horizontal zones, production rate is typically higher at the heel of the well than at the toe. The resulting imbalanced production profile may cause early water or gas breakthrough into the wellbore. Once coning occurs, well production may be severely decreased due to limited flow contribution from the toe. To eliminate this imbalance, inflow control devices (ICDs) are placed in each screen joint (sandstone formations) or debris barrier (carbonate formations) to balance the production influx profile across the entire lateral length and compensate for permeability variation. This creates equal production through each joint of screen to maximize recovery and rate. Pressure drop is created through restriction or friction mechanisms. Restriction uses small holes or orifices to restrict flow. Friction utilizes surface friction of a long channel to create the required pressure drop. ICDs to effectively balance production inflow depend upon their ability to resist erosion. Because these ICDs are permanent downhole components, their long-term reliability is imperative. Factors that determine erosion potential of ICD designs are fluid velocity, fluid particle concentration and design geometry. Calculations and computational fluid dynamics (CFD) modeling can be used to predict values for several factors independently, but not as a complete system. A full-scale erosion test is the most accurate way to demonstrate how the interaction of erosion factors affects the long-term reliability of downhole components. This paper will detail the methodology behind ICD design, the use of CFD analysis in determining erosion potential, as well as the analysis of full-scale ICD erosion testing conducted at an independent testing laboratory. Introduction The purpose of inflow control devices is to effectively balance well production throughout the entire operational life of the completion to optimize hydrocarbon recovery. Since a typical well with ICDs can be in production from 5 to >20 years, the long-term reliability of such a device is crucial to the well's overall success. The significant factor in the reliability of an ICD is its ability to maintain a uniform influx over the well life. If an ICD is not able to maintain a uniform flux rate, increased localized production rates will occur and the well will become unbalanced. This will render the ICD ineffective leading to premature water and/or gas breakthrough and possible loss of sand control. The primary factor in maintaining a uniform influx is the ability for the device to resist erosion from fluid borne particles. During production, formation fines that are produced through the screen also pass through the ICD. These fines can and will erode an ICD over time. The rate of erosion will depend on the following factors: particle size, particle concentration and fluid velocity. The first two factors are dependent on well conditions, while the third is dependent on ICD geometry and design. Currently, there are two different types of ICD designs in the industry: orifice and helical-channel. They use two different methods to achieve a uniform inflow profile. The orifice type ICD uses fluid constriction to generate a differential pressure across the device. This method essentially forces the fluid from a larger diameter down through a smaller diameter, creating a back pressure. This overall change in pressure is what allows the ICD to function. The helical-channel ICD, however, uses surface friction to generate a similar pressure drop. The helical channel design is one or more long flow channels that are wrapped around the basepipe of the screen. When fluid flows through the channels, fluid rheology and channel characteristics interact to create a designed pressure drop.

In long horizontal wells, oil production rate is typically affected by the reservoir heterogenities, heel to toe effect and mobility ratio. The resulting imbalanced production profile may cause early water or gas breakthrough into the wellbore. Once coning occurs, well fluid production may be severely decreased due to limited flow contribution from the toe or from reservoir areas with high flow resistance in the porous media. To eliminate this imbalance, passive inflow control devices (PICDs) are placed in each screen joint or inflow point to balance the production influx profile across the entire lateral length and compensate for permeability variation.PICD performance in producer (oil, gas, and high gas/oil ratio environments) wells under different operational conditions will be presented to show the technical benefits of this technique as well as their improved recovery efficiencies when compared to non-PICD completions. Fluid viscosity insensitivity of the PICD is critical to minimize preferential water flow whenever water breaks through into the well. The quantification of the benefits of this completion technique was performed using a fully integrated reservoir simulator where the PICD flow performance characteristic (as a function of fluid properties and geometry), well completion description (packers, blank pipe, gravel pack, annulus flow, etc.) and reservoir simulation are considered. Shutting off whole sections that have unacceptably high water and/or gas production using the latest PICD feature is also modeled to show improved recovery performance. This paper details the development of the latest-generation PICD design concept. Because these PICDs are permanent downhole components, their long-term reliability is imperative, and these new developments will improve their resistance to erosion and their ability to effectively balance inflow. Computational flow dynamics (CFD) analysis was used extensively to characterize the new design, under liquid and gas conditions, along with actual full-scale flow testing.

In long horizontal wells, production rate is typically higher at the heel of the well than at the toe. The resulting imbalanced production profile may cause early water or gas breakthrough into the wellbore. Once coning occurs, well production may be severely decreased due to limited flow contribution from the toe. To eliminate this imbalance, inflow control devices (ICDs) are placed in each screen joint to balance the production influx profile across the entire lateral length and to compensate for permeability variation. Pressure drop in an ICD is created through either restriction or friction mechanisms. Restriction mechanisms rely on a contraction of the fluid flow path to generate an instantaneous pressure drop, resulting in higher velocities, and are thus more prone to long-term erosion damage as well as plugging during mud flowback. A restriction device, however, is less sensitive to viscosity properties of the fluid. A frictional device, which creates a pressure drop over a distributed length, is less likely to erode due to lower fluid velocities, but is more sensitive to viscosity changes. Viscosity insensitivity is desired to minimize preferential water flow whenever water breaks through into the well. This paper will detail the development of a new hybrid design concept that uses the best features of the restricting and friction designs, while minimizing the less desirable characteristics. Because these ICDs are permanent downhole components, their long-term reliability is imperative, and these new developments will improve their resistance to erosion and their ability to effectively balance inflow. Conceptual fluid dynamics analysis was used extensively to characterize the new design, along with actual full-scale flow testing. Introduction The purpose of inflow control devices (ICDs) is to effectively balance well production throughout the entire operational life of the completion to optimize hydrocarbon recovery. Since a typical well with ICDs can be in production from 5 to >20 years, the long-term reliability of such a device is crucial to the well's overall success. The significant factor in the reliability of an ICD is its ability to maintain a uniform influx over the well life. If an ICD is not able to maintain a uniform flux rate, increased localized production rates will occur and the well will become unbalanced. This will render the ICD ineffective, leading to premature water and/or gas breakthrough and possible loss of sand control. At some stage in a well's life, water may break through into the wellbore in certain sections due to heterogeneity of the formation and/or vertical fractures. Ideally, once this occurs, flow contribution from these water-producing zones should not be greater than the oil-producing sections. In production wells with higher-viscosity oil (>10 cp.), ICD type selection becomes a more critical factor due to the larger difference in viscosity between the oil and produced water. The pressure reduction mechanism in an ICD in this situation must have the lowest sensitivity to viscosity to maintain an even flow profile across the entire lateral wellbore. A restrictive-type ICD thus will provide best results in this regard due to its lower sensitivity to viscosity. This type of ICD however, has a greater potential for long-term erosion and lower plugging resistance. The ideal solution is to provide the lower viscosity sensitivity of the restrictive device with the lower erosion and higher plugging resistance of the frictional design. This means using the restrictive pressure loss mechanism while limiting the fluid velocity through the device below the critical level which will cause erosion. Limiting the fluid velocity also can result in increased minimum flow area if configured efficiently.