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Characterization and Erosion Modeling of a Nozzle-Based Inflow-Control Device

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Characterization and Erosion Modeling of a Nozzle-Based Inflow-Control Device DC186090 DOI: 10.2118/186090-PA Date: 8-May-17 Stage: Page: 1 Total Pages: 10 Characterization and Erosion Modeling of a Nozzle-Based Inflow-Control Device Jo´gvan J. Olsen and Casper S. Hemmingsen, Technical University of Denmark; Line Bergmann, Welltec; Kenny K. Nielsen and Stefan L. Glimberg, Lloyd’s Register Consulting—Energy; and Jens H. Walther, Technical University of Denmark Summary sure drop, and two experiments showed no change. No previous In the petroleum industry, water-and-gas breakthrough in hydro- research was found that showed erosion in ICDs analyzed by use carbon reservoirs is a common issue that eventually leads to of numerically simulated particles. uneconomic production. To extend the economic production life- To prevent erosion from occurring in the ICDs, large particles time, inflow-control devices (ICDs) are designed to delay the are filtered upstream from the flow with sand screens. When water-and-gas breakthrough. Because the lifetime of a hydrocar- investigating erosion, the primary erosion factors are particle size, bon reservoir commonly exceeds 20 years and it is a harsh envi- particle concentration, particle shape, particle velocity, angle of ronment, the reliability of the ICDs is vital. impact, and wall material (Coronado et al. 2009; Oka et al. 2009). With computational fluid dynamics (CFD), an inclined nozzle- For the present case, sand-particle sizes 100 to 1000 mm in diame- based ICD is characterized in terms of the Reynolds number, dis- ter are investigated. The larger particles can penetrate the sand charge coefficient, and geometric variations. The analysis shows screen initially, whereas only the smaller particles will pass that especially the nozzle edges affect the ICD flow characteris- through after a natural sandpack has built up on the sand screen tics. To apply the results, an equation for the discharge coefficient (Feng et al. 2012). In addition, Zamberi et al. (2014) show that is proposed. sand-screen erosion can occur, allowing the large sand particles The Lagrangian particle approach is used to further investigate to pass through. the ICD. This allows for erosion modeling by injecting sand par- The nozzle-based ICDs have been deployed in wells since ticles into the system. By altering the geometry and modeling sev- 2015, for operators in West Africa and operators in the Middle eral scenarios while analyzing the erosion in the nozzles and at East. The applications have been different: Some were installed to the nozzle edges, an optimized design for incompressible media is use the ICDs in the application as gas lift valve and some in the found. With a filleted design and an erosion-resistant material, the application as zonal-production valve. Since the end of 2016, mean erosion rate in the nozzles may be reduced by a factor of more than 35 ICDs have been installed and used in wells, and more than 2,500. more than 250 valves have been ordered. The objective of this pa- per is to use numerical methods to characterize and investigate erosion for a nozzle-based ICD with varying geometry. The pur- Introduction pose is to optimize the ICD in terms of erosion to improve long- It is common to use long horizontal wells to increase reservoir time performance and to present the results with simple equations contact and hydrocarbon recovery (Lien et al. 1991). Because hor- ready to implement in reservoir simulators. izontal wells typically have a higher production at the heel than at the toe of the well as a result of uneven formation damage and the CFD Formulation pressure difference in the long pipe, premature water or gas break- With CFD, the ICD can be analyzed for a range of scenarios by through is a common issue (Birchenko et al. 2010; Feng et al. spatially discretizing the domain and solving the fundamental 2012). Eventually, because of the difference in density and viscos- fluid-dynamics equations. This allows for numerically analyzing ity of oil, water, and gas, cresting occurs, severely decreasing the ICD in terms of flow characteristics and erosion rates. hydrocarbon production (Joshi 1991). Placing ICDs along the completion introduces a passively controlled pressure drop, and can result in a more uniform influx along the completion. This Fundamental Equations for Incompressible Flow. The govern- can significantly delay the cresting, and gives a potential for a ing equations for solving the flow are the Navier-Stokes and conti- higher reservoir recovery. Fig. 1 illustrates how ICDs can extend nuity equations. Because the maximum simulated pressure reservoir lifetime compared with openhole completions. difference will be Dp ¼ 20 bar, gas release and viscosity changes Because a hydrocarbon reservoir is typically in production for are assumed negligible. In addition, with data from Lien et al. 3 5to> 20 years (Garcia et al. 2009), the longtime reliability of the (1991), the change in density is only 1.7 kg/m (0.2%) at Dp ¼ 20 completion is important. Most ICDs have to be set to introduce bar, meaning the oil can be assumed incompressible. To save the correct pressure drop before entering the well. Therefore, it is computational time, the steady-state solution can be found. The important that they can maintain their planned characteristics, governing equations are modeled by splitting the velocity ui into a 0 because repairing or interchanging components in a well is often mean (ui) and a fluctuating component (ui), not a viable option. In particular, erosion and plugging can lead to 0 the deviation of the planned inflow profile (Visosky et al. 2007; ui ¼ ui þ ui; ..............................ð1Þ Garcia et al. 2009). Because nozzle-based ICDs are prone to ero- sion (Zeng et al. 2013), their performance has to be known for a here written in Einstein notation. large range of scenarios to ensure that the planned inflow charac- The mean continuity equation for an incompressible fluid is teristics will be maintained throughout the entire reservoir life- time. The current research on erosion of ICDs is outlined by Greci @u j ¼ 0; .................................ð2Þ et al. (2014). They found five examples of experimental research @x in which three experiments showed less than 6% change in pres- j where uj is the velocity vector and xj denotes the spatial Copyright VC 2017 Society of Petroleum Engineers coordinate. Original SPE manuscript received for review 7 February 2016. Revised manuscript received The incompressible time-averaged Navier-Stokes equation for review 11 February 2017. Paper (SPE 186090) peer approved 16 February 2017. (White 2006) for solving the fluid momentum is 2016 SPE Drilling & Completion 1 ID: jaganm Time: 16:39 I Path: S:/DC##/Vol00000/170014/Comp/APPFile/SA-DC##170014 DC186090 DOI: 10.2118/186090-PA Date: 8-May-17 Stage: Page: 2 Total Pages: 10 Gas T = 0 years Gas T = 2 years Heel Heel Toe Toe Oil Oil Water Water Gas T = 0 years Gas T = 2 years ICD ICD Heel Heel Toe Toe Oil Sandscreen Oil Sandscreen Water Water Fig. 1—Inflow-control devices (ICDs) can delay water/gas breakthrough, thereby extending reservoir lifetime. The two upper images show the cresting effect potentially occurring when using an openhole completion, and the bottom two images show the effect of even oil influx obtained with ICDs. Modified from Olsen (2015). @u @ @u @u ticles, because the turbulent eddies are not resolved when using a qu i ¼ Àpd þ l i þ j À s ; ....... ð3Þ j @x @x ij @x @x ij RANS model. j j j i To calculate the particle trajectory after impacting a wall, the where q is the density, p is the pressure, dij is the Kronecker delta, particle-restitution coefficients are set for the normal restitution coefficient (NRC) and the tangential restitution coefficient (TRC). l is the dynamic viscosity, and s ¼ qu0u0 is the Reynolds stress ij i j For steel oilfield control valves, Forder et al. (1998) propose the term. Because only the mean flow properties will be referenced, following coefficients: the bar symbol is removed in future notation. To provide closure, the Reynolds stress is modeled with Reyn- NRC ¼ 0:988 À 0:78b þ 0:19b2 À 0:024b3 þ 0:027b4; olds-averaged Navier-Stokes (RANS) equations. Three turbulence models will be used: The two-equation realizable k-e model (Shih ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁð5Þ et al. 1995), the two-equation shear-stress transport (SST) k-x TRC ¼ 1 À 0:78b þ 0:84s2 À 0:21b3 þ 0:028b4 À 0:022b5; model (Menter 1994), and the one-equation Spalart-Allmaras model (Spalart and Allmaras 1994). Because turbulence theory is ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁð6Þ a very large and complex field, we refer to Wilcox (1994) for fur- ther discussions. where b is the particle-incidence angle. The exact restitution coef- ficients are not considered as vital if the particles only affect the nozzle walls once. Lagrangian Multiphase Formulation. To solve particle motion, Erosion Model. When modeling erosion, the erosion rate on a the Lagrangian formulation is used. Here, the sand grains are solid-surface element, Ef, is defined as the amount of mass eroded modeled as parcels, in which each parcel represents multiple sand from a face area over time: grains with a given density, diameter, and position. Instead of 1 X modeling every particle, parcels allow for a statistical approach E ¼ m_ e ; .......................... ð7Þ with which it is necessary to model only a sufficient number of f A p r f pðf Þ parcels. The number of parcels required depends on the flow field and geometry. The flow is assumed dilute, meaning particle/parti- where Af is the face area, m_ p is the impacting parcel mass flow cle interactions are neglected for the present case (Elghobashi rate, and er is the user-defined volumetric erosion rate per mass of 1994).
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