Inflow Profile Research Articles

GINI coefficient: An effective way to evaluate inflow profile equilibrium of horizontal wells in Shengli Oil Field

A new Inflow Gini Coefficient (GN) is introduced to directly and quantitatively to evaluate the equilibrium of horizontal well inflow profile. GN reflects to the difference of inflow profiles between actual well and ideal well simulated by a 3D oil-water black oil model. GN ranges from 0 to 1, and profile becomes more unbalanced with larger GN. 70 sample wells in Shengli Oilfield have been statistically studied to relate GN to production performance parameters, and then, 0 < GN < 0.1 is classified as balanced grade, 0.1 < GN < 0.3 as unbalanced grade, while GN > 0.3 as extremely unbalanced grade. GN selected the best schemes of profile control for 20 application wells, and averagely increased daily oil production from 13.9 m3/d to 20.2 m3/d, decreased water cut from 82.5% to 75.6% when GN dropped from 0.246 to 0.127. Further, the variation of daily oil production and water cut after profile control is found to increase exponentially with linear decrease of GN. It can be concluded that, GN provides effective guidance for inflow control of horizontal well to ensure successful results, the performance of horizontal well with more unbalanced inflow profile, especially GN > 0.3, always has great potential to be improved.

Impact of Long-Term Water Inflow Uncertainty on Wholesale Electricity Prices in Markets with High Shares of Renewable Energies and Storages

Renewable energy shares in electricity markets are increasing and therefore also require an increase in flexibility options. Conventional electricity price modelling with optimisation models in thermally dominated markets is not appropriate in markets with high shares of renewable energies and storages because price structures are not adequately represented. Previous research has already identified the impact of uncertainty in renewable energy feed-in on investment and dispatch decisions. However, we are not aware of any work that investigates the influence of uncertainties on price structures by means of optimisation models. Appropriate modelling of electricity price structures is important for investment and policy decisions. We have investigated the influence of uncertainty concerning water inflow by applying a second stage stochastic dual dynamic programming approach in a linear optimisation model using Norway as an example. We found that the influence of uncertainty concerning water inflow combined with high shares of storages has a strong impact on the electricity price structures. The identified structures are highly influenced by seasonal water inflow, electricity demand, wind, and export profiles. Additionally, they are reinforced by seasonal primary energy source prices and import prices. Incorporating uncertainties in linear optimisation models improves the price modelling and provides, to a large extent, an explanation for the seasonal patterns of Norwegian electricity market prices. The paper explains the basic pricing mechanisms in markets with high shares of storages and renewable energies which are subject to uncertainty. To identify these fundamental mechanisms, we focused on uncertainty regarding water inflow, but the basic results hold true for uncertainties regarding other renewable energies as well.

Finite-difference modeling of the inflow profile in an isolated homogeneous isotropic partially opened reservoir

The article is devoted to the study of tributary profiles arising from the selection of hydrocarbons from partially opened reservoirs. The calculations were performed based on the finite-difference program for calculating the pressure and velocity fields in the formation, based on the solution of the problem of the pressure field in an isolated isotropic homogeneous formation, localized in the range from H 1 to − H 2 and perforated in the range − H &lt; z &lt; H , which is completely contained in the interval of the reservoir. Graphical dependencies are constructed for the pressure field, the vertical and horizontal components, and the velocity modulus of the fluid filtered from the periphery to the well. Level lines for the indicated fields are presented and, based on their analysis, important regularities of the flow are revealed. A computational experiment showed that there are no vertical flows at the hole in the perforated part of the formation, and when they are removed from the well, they are non-zero. It was shown that interlayer flows exist even in homogeneous partially opened formations. At the same time, the inflow from an imperfectly opened homogeneous isotropic reservoir producing in a given depression mode is not uniform, and the maximum modulus of the horizontal velocity component in all curves is reached at the boundaries of the perforation interval. It is shown that in the center of a symmetrically perforated and imperfectly opened formation a minimum specific inflow is observed.

Large-Eddy Simulation of the Flow Developing in Static and Rotating Ribbed Channels

Abstract In the present work, the turbulent flow fields in a static and rotating ribbed channel representative of an aeronautical gas turbine are investigated by the means of wall-resolved compressible large-Eddy simulation (LES). This approach has been previously validated in a squared ribbed channel based on an experimental database from the Von Karman Institute (Reynolds and rotation numbers of about 15,000 and ±0.38, respectively). LES results prove to reproduce differences induced by buoyancy in the near rib region and resulting from adiabatic or anisothermal flows under rotation. The model also manages to predict the turbulence increase (decrease) around the rib in destabilizing (stabilizing) rotation of the ribbed channels. On this basis, this paper investigates in more detail the spatial development of the flow along the channel and its potential impact on secondary flow structures. More specifically and for all simulations, results of the adiabatic static case exhibit two contra-rotating structures that are close to the lateral walls of the channel induced by transversal pressure difference created by the ribs. These structures are generated after the first ribs and appear behind all inter-rib sections, their relative position is partly affected by rotation. When considering the stabilizing rotating case, two additional contra-rotating structures also develop along the channel from the entrance close to the low-pressure wall (rib-mounted side). These vortices are due to the confinement of the configuration, inflow profile and are the result of Coriolis forces induced by rotation. Görtler vortices also appear on the pressure wall (opposite to the rib-mounted side). In the destabilizing rotating case, these two types of secondary structures are found to co-exist, and their migration in the channel is significantly different due to the presence of the ribs on the pressure side. Finally, it is shown that heat transfer affects only marginally the static and stabilized cases while it changes more significantly the flow organization in the destabilizing case mainly because of enhanced heat transfer and increased buoyancy force effects.

СИСТЕМА УПРАВЛЕНИЯ УСТРОЙСТВОМ КОНТРОЛЯ ПРИТОКА ФЛЮИДА В СКВАЖИНЕ

Актуальность исследования состоит в том, что решением преждевременного прорыва воды или газа в горизонтальной скважине из-за неоднородности профилей притока вдоль оси горизонтального ствола, является изменение пластового давления на различных участках, а также при разработке контактных месторождений, особенно по мере истощения залежи, могут служить устройства контроля притока флюида. Различают активные Interval Control Valve (ICV) или пассивные Inflow Control Device (ICD) устройства. Устройства ICD способны выровнять приток вдоль горизонтальной скважины за счет создания дополнительного сопротивления потоку жидкости, зависящего от величины притока на данном горизонтальном участке. Недостаток современных ICD в том, что они не имеют возможности регулирования и приведения пассивных устройств в действие после установки в стволе скважины. В связи с тем, что имеются риски связанные с неопределенностью в описании свойств пласта, которые присутствуют на всех стадиях разработки месторождения недостаток ICD оказывается существенным. Системы ICV приводятся в действие дистанционно с поверхности скважины, но не способны определять характер поступающего флюида (нефть, газ, вода) в скважину и принимать решение в автоматическом режиме. Цель: разработка новой конструктивной схемы устройства контроля притоком с возможностью непрерывного мониторинга характера поступающей жидкости, и программного обеспечения для управления клапаном с устья скважины. Объекты: горизонтальная скважина и устройство контроля притоком флюида. Методы: имитационное моделирование Simulink, нейронные сети, матричные методы, методы линеаризации нелинейных уравнений. Результаты. Предложена новая конструктивная схема устройства контроля притока в горизонтальной скважине, позволяющая непрерывно оценивать характер поступающего флюида. Данная конструкция позволяет в автоматическом режиме регулировать положение исполнительного механизма по данным измерительных приборов. Дано математическое описание работы клапана. Разработана модель клапана в среде моделирования Simulink, с использованием матричного подхода и нейронных сетей, для построения качественной зависимости положения клапана от значения создаваемого перепада давления. Приведены результаты работы блока нейронной сети и конечный результат моделирования.

Numerical Investigation of a Two-Bladed Propeller Inflow at Yaw

The development of faster computing power and nonintrusive experimental techniques has allowed for the advancement in computational fluid dynamics (CFD) validation and the greater understanding of aerodynamic conditions previously deemed too extreme to accurately measure. To this end, a numerical study is conducted that focuses on a propeller at yaw. Current low-order methods are reliant upon an accurate inflow profile to determine overall blade loading patterns. To improve such methods, CFD can be used to determine an initial inflow profile from which to conduct additional lower-order calculations. Therefore, to ensure that CFD is able to accurately capture yawed inflow profiles, a validation study is conducted that compares numerical simulations against experiments. Good agreement is found between the two methods, and subsequently the azimuthal variation in skin friction and induced angle of attack, as a result of the yawed conditions, is analyzed.

Nonaqueous, Nondamaging Fluid Implemented Offshore Abu Dhabi

This article, written by JPT Technology Editor Judy Feder, contains highlights of paper SPE 192735, “The Evolution of Nondamaging Fluid Design and Implementation Offshore Abu Dhabi,” by Catalin Ivan, SPE, ExxonMobil; Yousif Saleh Al Katheeri, Melanie Reichle, Khalid Akyabi, James Thomas Ryan, Sheldon Peter Anthony Seales, SPE, and Sigit Kustanto, SPE, ADNOC; Laurie Hayden, M-I SWACO; and Christoper Steele, SPE, ELKEM, prepared for the 2018 Abu Dhabi International Petroleum Exhibition and Conference, 12–15 November, Abu Dhabi. The paper has not been peer reviewed. This paper covers the 7-year history of drilling-fluids application in a reservoir drilling campaign offshore Abu Dhabi, from the early use of a solids-free, brine-/water-based mud to the recent application of nondamaging, nonaqueous fluids (NAFs) with micronized acid-soluble ilmenite. The complete paper provides details about the integration of filter-cake breakers with various types of drilling fluids, from dormant drilling-fluid additives to delayed, pH- and temperature-activated breakers. The paper describes the steps taken to achieve these performance goals, including changes to the oil/water ratio (OWR), internal phase composition [heavier calcium briomide (CaBr2) instead of calcium chloride (CaCl2)], and a micronized, acid-soluble ilmenite as a•weighting agent. Development Highlights A key objective for the offshore Abu Dhabi project was to drill longer horizontal 8½-in. intervals while retaining zero-skin completions. This necessitated reducing the torque and drag and coefficients of friction (COF). Achieving these design criteria required developing a nondamaging, nonaqueous (NAF) drilling fluid complemented with a filter-cake-removal breaker system. Emphasis was placed on the design of an NAF that combined the desired properties of low rheological profile for equivalent-circulating-density (ECD) management, low COF, and nondamaging water-based-mud (WBM) formulation. Four different generations of breakers for water-based reservoir drill-in fluids (RDF) were developed and used before moving to nondamaging NAF. The NAF went through three iterations in addition to fine-tuning of the breaker package. Data related to well information, reservoir rock type, and completion type were gathered and analyzed. Fluid interaction and other studies were performed to determine suitable fluid type and formulation. Other factors taken into consideration included offset well data, drilling requirements, environmental considerations, logging requirements, and likely mud-damaging mechanisms. Extensive laboratory tests were conducted, some of which included compatibility of various fluids, return permeability, changes to the OWR, internal phase composition, and a micronized, acid-soluble ilmenite as a weighting agent. The breaker systems saw the same extent of refinement, from enzymes to delayed organic acid precursors and chelating agents, to evaluate the removal of the fluid filter cake by the breaker. Fluid formulations were evaluated and optimized. More than 80 extended-reach-drilling wells have been drilled using both water-based and nonaqueous RDFs, each with specially formulated breakers. These wells yielded learnings that contributed to the current design and formulations. Friction factors (FFs) obtained using RDF NAF proved to be much lower than those with RDF WBM. The lower FF enabled wells with longer horizontal sections to be drilled successfully and at significantly higher rates of penetration. Using micronized, acid-soluble ilmenite lowered ECD as compared with sized calcium carbonate. Additionally, the evolution of breaker formulations allowed for longer breakthrough time, which allowed for better coverage of the lateral, better removal of the filter cake, and, ultimately, enhanced production through improved inflow profiles. The end result of the continuous improvement in reservoir drilling fluid was an NAF that combined the desired properties of low rheological profile for ECD management and low COF, and was•nondamaging.

AD/RANS Simulations of Wind Turbine Wake Flow Employing the RSM Turbulence Model: Impact of Isotropic and Anisotropic Inflow Conditions

The Reynolds-averaged Navier–Stokes (RANS)-based generalized actuator disc method along with the Reynolds stress model (AD/RANS_RSM) is assessed for wind turbine wake simulation. The evaluation is based on validations with four sets of experiments for four horizontal-axis wind turbines with different geometrical characteristics operating in a wide range of wind conditions. Additionally, sensitivity studies on inflow profiles (representing isotropic and anisotropic turbulence) for predicting wake effects are carried out. The focus is on the prediction of the evolution of wake flow in terms of wind velocity and turbulence intensity. Comparisons between the computational results and the measurements demonstrate that in the near and transition wake region with strong anisotropic turbulence, the AD/RANS_RSM methodology exhibits a reasonably good match with all the experimental data sets; however, in the far wake region that is characterized by isotropic turbulence, the AD/RANS_RSM predicts the wake velocity quite accurately but appears to over-estimate the wake turbulence level. While the introduction of the overall turbulence intensity is found to give an improved agreement with the experiments. The performed sensitivity study proves that the anisotropic inflow condition is recommended as the profile of choice to represent the incoming wind flow.

Linear and radial flow modelling of a waterflooded, stratified, non-communicating reservoir developed with downhole, flow control completions

Forecasts of the performance of waterflooded oil-field have been prepared for many years using fractional flow models, such as those by (Buckley-Leverett, 1942) (BL), (Welge, 1952) and (Dykstra-Parsons, 1950) (DP), to estimate the vertical sweep efficiency between wells. These methods, and their later modifications, formed the theoretical basis for designing a water-flooded oil-field. Advanced Well Completions (AWC) incorporating downhole flow control device (FCD) technology have become a proven method for modifying a production well's inflow profile, delaying water breakthrough, improving sweep efficiency and enhancing recovery.This manuscript extends the fractional flow model describing the performance of a waterflooded, stratified-reservoir with an AWC installed in the production well. The piston-like behaviour of the water-front described by previous, semi-analytical models is extended here to the linear and radial flow modelling of more realistic displacement profiles.This paper describes the theoretical basis and application workflow along with several case studies illustrating their performance and value. The accuracy of the new, semi-analytical models are verified by comparison against the results from a numerical reservoir simulator. Model limitations and possible future extension are also discussed.The workflow can be implemented as either a production forecast or a diagnostic tool for an AWC well in a waterflooded oil-field. It provides one missing link between today's AWC design workflows and the long-term value evaluation of a specific AWC design when a commercial numerical simulation software is either not available or too time consuming.

New Assessment Scales for Evaluating the Degree of Risk of Wind Turbine Blade Damage Caused by Terrain-Induced Turbulence

The present study scrutinized the impacts of terrain-induced turbulence on wind turbine blades, examining measurement data regarding wind conditions and the strains of wind turbine blades. Furthermore, we performed a high-resolution large-eddy simulation (LES) and identified the three-dimensional airflow structures of terrain-induced turbulence. Based on the LES results, we defined the Uchida-Kawashima Scale_1 (the U-K scale_1), which is a turbulence evaluation index, and clarified the existence of the terrain-induced turbulence quantitatively. The threshold value of the U-K scale_1 was determined as 0.2, and this index was confirmed to not be dependent on the inflow profile, the influence of the horizontal grid resolution, and the influence of the computed azimuth. In addition, we defined the Uchida-Kawashima Scale_2 (the U-K scale_2), which is a fatigue damage evaluation index based on the measurement data and the design value obtained by DNV GL’s Bladed. DNV GL (Det Norske Veritas Germanischer Lloyed) is a third party certification body in Norway, and Bladed has been the industry standard aero-elastic wind turbine modeling software. Using the U-K scale_2, the following results were revealed: the U-K scale_2 was 0.86 &lt; 1.0 (within the designed value) in the case of northerly wind, and the U-K scale_2 was 1.60 &gt; 1.0 (exceeding the designed value) in the case of easterly wind. As a result, it was revealed that the blades of the target wind turbine were directly and strongly affected by terrain-induced turbulence when easterly winds occurred.

Staged Premium Screen Completion Design for Horizontal Well Based on Laboratory Test: A Successful Application in Block 451, Shengli Oil Field

Staged premium screen has been applied to balance the inflow profile of horizontal well under open hole completion in Shengli Oil Field, China. Perforation density of base pipe is the key parameter of staged screen for inflow control, however, it is used to be determined by only considering drawdown due to perforation itself, ignoring two dominant parts caused by formation sand filter cake around screen and sand retention material, therefore the decision plan is not suitable. To solve this problem, a laboratory apparatus was run to test a screen sample, and thoroughly analyzed the effect of perforation density on total inflow control drawdown. A base pipe was also tested, working as a reference to screen sample. The test simulated down hole flowing condition in Well DXY451P21, Block 451, Shengli Oil Field, test results were directly utilized to design staged premium screen for this target well. Finally, the following conclusions can be drawn: pressure drop in screen sample is much sensitive to perforation density, and is obviously larger than that in base pipe sample; flowing pressure is mainly lost in formation sand filter cake and sand retention material, where the flow pattern is seepage flow; perforations on base pipe of premium screen mainly play a part in regulating flowing field, i.e. smaller perforation density will lead produced liquid to flow a longer distance in seepage media and bring a larger additional drawdown; the production performance of Well DXY451P21 is much better than adjacent wells, and promotes economic benefits.

Bubble and conical forms of vortex breakdown in swirling jets

Experimental investigations of laminar swirling jets had revealed a new form of vortex breakdown, named conical vortex breakdown, in addition to the commonly observed bubble form. The present study explores these breakdown states that develop for the Maxworthy profile (a model of swirling jets) at inflow, from streamwise-invariant initial conditions, with direct numerical simulations. For a constant Reynolds number based on jet radius and a centreline velocity of 200, various flow states were observed as the inflow profile’s swirl parameter $S$ (scaled centreline radial derivative of azimuthal velocity) was varied up to 2. At low swirl ($S=1$) a helical mode of azimuthal wavenumber $m=-2$ (co-winding, counter-rotating mode) was observed. A ‘swelling’ appeared at $S=1.38$, and a steady bubble breakdown at $S=1.4$. On further increase to $S=1.5$, a helical, self-excited global mode ($m=+1$, counter-winding and co-rotating) was observed, originating in the bubble’s wake but with little effect on the bubble itself – a bubble vortex breakdown with a spiral tail. Local and global stability analyses revealed this to arise from a linear instability mechanism, distinct from that for the spiral breakdown which has been studied using Grabowski profile (a model of wing-tip vortices). At still higher swirl ($S=1.55$), a pulsating type of bubble breakdown occurred, followed by conical breakdown at 1.6. The latter consists of a large toroidal vortex confined by a radially expanding conical sheet, and a weaker vortex core downstream. For the highest swirls, the sheet was no longer conical, but curved away from the axis as a wide-open breakdown. The applicability of two classical inviscid theories for vortex breakdown – transition to a conjugate state, and the dominance of negative azimuthal vorticity – was assessed for the conical form. As required by the former, the flow transitioned from a supercritical to subcritical state in the vicinity of the stagnation point. The deviations from the predictions of the latter model were considerable.

Low Reynolds number multirotor aerodynamic wake interactions

Multirotor vertical take-off and landing uninhabited aerial vehicles can be built in numerous configurations. This makes them a preferred choice of platform for a wide range of commercial applications. Rotor–rotor aerodynamic interactions play an important role in the performance of a UAV. Bi-rotor configurations are studied experimentally using high-speed stereo particle image velocimetry and performance measurements. Important multirotor wake interaction phenomena are identified. Two kinds of vortex–vortex, four kinds of vortex–vortex sheet, and two kinds of vortex–hub interactions are discovered at different sub-ranges of the tested configurations. The primary building components of multirotor downwash are recognized by observing the mean rotor inflow and outflow velocity profiles. Comparison of performance trends with high Reynolds number rotor data shows better than expected figure of merit for the upper rotor and the combined system.

Multiphase coupling of a reservoir simulator and computational fluid dynamics for accurate near-well flow

Near-well flow analysis is an important tool for gaining detailed insight of the flow behaviour and for improving well design and production optimization of real reservoirs. One challenge of accurate numerical modelling of the flow field in the vicinity of the well is related to the scale disparity factor in space and time. The numerical scale gap between the reservoir and the wellbore justifies the representation of a well as a point or line sink/source term in traditional reservoir models. However, standard numerical techniques for reservoir simulation are incapable of resolving the near-singular character of the pressure field in the vicinity of the well. Under the assumption that all length scales have impact on flow patterns, we present a proof-of-concept study aimed at improving the quality of the numerical simulation by considering the geometry and fluid flow near the wellbore in a fully connected system, thus accounting for the fine scale phenomena by means of a hybrid Navier-Stokes/Darcy wellbore model coupled with a full scale reservoir model. A weak coupling method based on fixed-point iterations, that preserves the mass flux transport across the coupled interface, while adjusting productivity indices, is demonstrated via numerical experiments. Several different numerical experiments are performed to demonstrate the versatility and the improved well performance insight that the coupled method offers, including horizontal well inflow profile, influence of formation damage and optimal well configuration.

A new autonomous inflow control device designed for a loose sand oil reservoir with bottom water

A downhole automatic inflow control device (AICD) can effectively delay the premature water breakthrough caused by unbalanced inflow profiles along the horizontal to improve production. However, solid particles seriously affect and restrict the normal operation of the AICD. In this paper, a new Cyclone Inflow Control Device (CICD) designed based on the principle of the cyclone to deal with the fine particles. The water control performance of the CICD was tested experimentally. The experimental results show that the pressure drop caused by the water flow was higher than the pressure drop of the oil flow at the same flow rate. The flow field distribution and the ability to deal with solids in the designed CICD are simulated via computational fluid dynamics (CFD). The effects of the structural parameters (inlet number, chamber slope, installation location) and fluid parameters (viscosity, flow rate and density) on the performance of the CICD were simulated. From the simulation results, we determined that: (1) Under the action of swirling flow, particles easily to accumulate in the ordinary disc swirling disk, and the funnel swirling disk can effectively discharge particles. (2) The pressure drop of the water flow is mainly produced in the swirl chamber, and the pressure drop of the oil flow mainly occurs at the inlet. (3) Adopting double inlets will not only ensure a higher pressure drop of the water flow, but will also reduce the pressure drop of the oil flow. (4) The larger the slope of the swirl chamber, the smaller the pressure drop that occurs, and the effect on the water flow is greater than the effect on the oil flow (5) The viscosity and flow rate have a greater influence on the performance of the CICD than the density.

Simulation of urban boundary and canopy layer flows in port areas induced by different marine boundary layer inflow conditions

Computational fluid dynamics (CFD) simulations and wind-tunnel (WT) tests can be considered as boundary-value problems, where the inlet boundary condition, which is usually obtained inferring inlet mean wind profiles from on-site measurements or other type of experimental data, represents the large-scale atmospheric forcing exerted at the outer limit of the urban model. It is not clear, however, to which extent the choice of different inflow wind speed profiles may affect WT and CFD results in the urban environment. In the present study, this aspect is investigated through the comparison of the wind flow fields simulated numerically and tested experimentally in an atmospheric boundary layer wind tunnel (ABLWT) within a district of Livorno city, Italy, called “Quartiere La Venezia”. Three different shapes of inflow profiles were tested using the CFD technique and the results were compared with each other: one is based on the approach-flow profiles measured upstream of the urban model in the WT test section (WT profile) and two are based on anemometric data corresponding to the approach-flow profile measured by means of a LiDAR wind profiler (LiDAR profile 1 and 2). The analysis showed that using different wind speed profiles does not affect significantly the results in the urban canopy layer (UCL), where correlations of 95% and 98% were found between the LiDAR profile 1 and 2 data and the WT profile data (at z = 0.02 m above the bottom), respectively. Conversely, the different inflow profiles strongly affected the results above the UCL. This means that the local-scale effects induced on the wind field in the UCL by the urban texture are dominated mainly by the larger-scale forcing, as within the canopy the flow remains topologically invariant despite the different inflow conditions.

Downwind flow behaviours of cuboid-shaped obstacles: modelling and experiments

Buildings or fence-like structures are frequently modelled as cuboids in simulations of environmental assessments. Understanding flows around and downwind of typical isolated buildings, in the form of cuboids, provide insightful building disposition strategies, which are particularly useful in the field of urban planning. Fast analytical models or computational numerical models are essential for sensitivity studies of various design parameters that require validation against field/experimental data. The aim of this study is to compare in detail the robustness of analytical perturbation models and the computational fluid dynamics (CFD) k − ε turbulence models for predicting the mean wake velocity defects along the centre line downwind of the cuboids, both in the near- and far-wake regions. Depending on aspect ratios of cuboids, the decay rate of maximum velocity defect behaves differently. Moreover, the CFD code over-predicts the magnitude of maximum defect in comparison with the perturbation models, whereas it over-predicts or under-predicts when compared to actual measurements. A physical explanation has been proposed in this paper. The steady CFD models, requiring less empirical input, are shown to provide satisfactory results for approximate computations of flows in the near- and far-wake regions of cuboid buildings with appropriate settings of inflow profiles and wall function.

Principles of rapid design of an inflow control device completion in homogeneous and heterogeneous reservoirs using type curves

This paper discusses the development and application of universal type-curves for the design of Advanced Well Completions (AWCs) equipped with passive (non-adjustable), flow control devices {a.k.a. Interval Control Devices (ICDs)}. This work provides an innovative, rapid approach to their design without the need for numerical simulators.AWCs equipped with ICDs aim to delay the early breakthrough of unwanted fluids in wells constructed close to a reservoir fluid contact. An uneven inflow profile due to reservoir permeability heterogeneity, multiple fluid contacts or an undulating well path needs to be managed. In addition, the Heel-to Toe effect (HTE) by frictional pressure loss due to fluid flow along the length of the completion interval also promotes a non-uniform inflow profile.The main AWC design challenge is to balance the trade-off between loss in well productivity from the added flow restrictions and the benefit of an improved inflow profile. This paper reviews the development of the analytical modelling of the inflow performance of horizontal wells with ICD completions, It presents new semi-analytical, mathematical models describing the ability of AWCs to mitigate production problems created by (reservoir) permeability heterogeneity and the (in-well) HTE. New dimensionless numbers allow the development of universal type-curves (TCs) for AWC design. The new workflow is illustrated for several case studies and the results validated by their good agreement with calculations made with the standard “well-reservoir” numerical simulator employed by engineers for this task.This novel approach for rapid analysis of the implications of well log data, such as that obtained shortly before the beginning the installation of the well completion, is the latest addition to the well completion engineering toolbox.

Сопоставление промыслово-геофизических и трассерных методов исследований для контроля профиля притока в горизонтальных скважинах с многостадийным гидроразрывом пласта

Сопоставление промыслово-геофизических и трассерных методов исследований для контроля профиля притока в горизонтальных скважинах с многостадийным гидроразрывом пласта

Combining Passive and Autonomous Inflow-Control Devices in a Trilateral Horizontal Well in the Alvheim Field

Summary In this paper we describe the analysis, test, and design work to deliver an optimal lower completion for a trilateral well by integrating passive and autonomous inflow-control devices (ICDs) (AICDs) at the Alvheim Field offshore Norway. In 2015, both passive ICDs and AICDs were tested in the laboratory with Alvheim fluids at reservoir conditions. The experimental flow testing demonstrated that the AICD chokes gas more efficiently than the passive ICD. The experimental results enabled correct modeling of AICDs in both the reservoir-simulation model and the simpler steady-state inflow model. The following lower-completion strategy was established for the new well: Where the well was close to the overlying gas cap, AICDs should be used, whereas passive ICDs with variable strength were to be used elsewhere to optimize the inflow. During the drilling phase, the steady-state model was updated with the as-drilled information; the lower-completion design for each branch focused on obtaining what was estimated to be an optimal inflow depending on the oil volume per drainage area. A key uncertainty in the design work was whether shaly zones along the wellbore would creep/collapse with time and act effectively as packers. The lower completion covered 7 km of reservoir penetration in the three branches, and 15 unique oil tracers were installed to evaluate the cleanup and the inflow profile along the well. The well started producing in May 2016 and a successful cleanup was confirmed by oil-tracer responses. In August 2016, a restart-tracer-sampling campaign was performed after a 12-day shut-in, and this formed the basis for a “chemical production log.” The tracer-based inflow interpretation was compared quantitatively with the model-predicted inflow and qualitatively to the tracer responses seen during the cleanup. The comparison confirmed that the lower completion works as initially planned. The interpretation further indicated that the upper zone has a lower degree of pressure support than the lower zone, and that the larger shaly sections have creeped/collapsed and act as packers. The well has exceeded predrill production expectations, with an average oil rate of 3375 std m3/d (21,240 STB/D) during the first production year. A large part of exceeding the predrill expectations is attributed to the lower-completion design, where the focus has been to optimize such that the whole well contributes, from the heel to all toes.