Theoretical and experimental study of motion and sinking time of Saxon Bowls

This work focuses on investigating the time of sinking of a Saxon bowl proposed by ‘International Young Physicists’ Tournament in 2020. A quasi-static model is built to simulate the motion path of the bowl and predict the sinking time subsequently. The model assumes an open axisymmetric bowl with a hole in its base. The hole is modelled as a pipe for which the flow profile is governed by a modified Bernoulli’s equation which has a Coefficient of Discharge (C_d) added to account for energy losses. The motion of the entire bowl is assumed to be in quasi-static equilibrium for an infinitesimal time interval to calculate the volumetric flow rate through the hole. The model is used to predict the sinking times of various bowls against independent variables - hole radius, bowl dimensions, mass of bowl, mass distribution of bowl, and Coefficient of Discharge - and predict the motion path of bowls of different, axisymmetric geometries. Characterisation of C_d was done by draining a bowl filled with water and measuring the time taken to do so. Experimental verification was completed through measuring sinking times of 3D printed hemispherical bowls of the different variables in water. Motion tracking of bowls with different geometries was done using computational pixel tracking software to verify the model’s predictive power. Data from experiments for sinking time against the variables corroborate with the model to a great degree. The motion path tracked, matched the modelled motion path to a high degree for bowls of different shapes, namely a hemisphere, cylinder, frustum, and a free-form axisymmetric shape. The work is poised for an undergraduate level of readership.

Viscoelastic properties of suspended cells measured with shear flow deformation cytometry

Numerous cell functions are accompanied by phenotypic changes in viscoelastic properties, and measuring them can help elucidate higher-level cellular functions in health and disease. We present a high-throughput, simple and low-cost microfluidic method for quantitatively measuring the elastic (storage) and viscous (loss) modulus of individual cells. Cells are suspended in a high-viscosity fluid and are pumped with high pressure through a 5.8 cm long and 200 μm wide microfluidic channel. The fluid shear stress induces large, near ellipsoidal cell deformations. In addition, the flow profile in the channel causes the cells to rotate in a tank-treading manner. From the cell deformation and tank treading frequency, we extract the frequency-dependent viscoelastic cell properties based on a theoretical framework developed by R. Roscoe that describes the deformation of a viscoelastic sphere in a viscous fluid under steady laminar flow. We confirm the accuracy of the method using atomic force microscopy-calibrated polyacrylamide beads and cells. Our measurements demonstrate that suspended cells exhibit power-law, soft glassy rheological behavior that is cell cycle-dependent and mediated by the physical interplay between the actin filament and intermediate filament networks.

Effects of different thermal modes of obstacles on the natural convective Al2O3-water nanofluidic transport inside a triangular cavity

This study investigates the Al2O3-water nanofluidic transport within an isosceles triangular compartment with top vertex downwards. The top wall is maintained isothermally cooled and left as well as right inclined walls are made uniformly heated. Two diamond-shaped obstacles are positioned inside the enclosure. The nanofluidic motion is supposed to be magnetically influenced. This investigation includes a fine analysis of how various thermal modes of obstacles affect the velocity and thermal profiles of the nanofluid. Appropriate similarity conversion leads to having a non-dimensional flow profile and is treated with Galerkin finite element scheme. The grid independency, experimental verification, and comparison assessments are directed to explore the model accuracy. The dynamic parameters like Rayleigh number [Formula: see text], nanoparticle volume fraction [Formula: see text], and Hartmann number [Formula: see text] are varied to perceive the noteworthy changes in isotherms, velocity, streamlines, and Nusselt number. The consequences specify average Nusselt number deteriorates for Hartmann number but escalates for nanoparticle concentration and Rayleigh number. Both heated and adiabatic obstacles exhibit high heat transport, while cold obstacles reveal the lowest magnitude in heat transmission. For Rayleigh number, cold obstacles reveal 34.51% heat transport enhancement, whereas it is 52.72% for heated obstacles compared to cold one. mathematics subject classification: 76W05

Production Performance Analysis of Western Siberia Mature Waterflood with Prime Diagnostic Metrics

The paper shares a practical case of production analysis of mature field in Western Siberia with a large stock of wells (> 1,000) and ongoing waterflood project. The main production complications of this field are the thief water production, thief water injection and non-uniform vertical sweep profile. The objective of the study was to analyse the 30-year history of development using conventional production and surveillance data, identify the suspects of thief water production and thief water injection and check the uniformity of the vertical flow profile. Performing such an analysis on well-by-well basis is a big challenge and requires a systematic approach and substantial automation. The majority of conventional diagnostic metrics fail to identify the origin of production complications. The choice was made in favour of production analysis workflow based on PRIME metrics, which automatically generates numerous conventional production performance metrics (including the reallocated production maps and cross-sections) and additionally generates advanced metrics based on automated 3D micro-modelling. This allowed to zoom on the wells with potential complications and understand their production/recovery potential. The PRIME analysis has also helped to identify the wells and areas which potentially may hold recoverable reserves and may benefit from additional well and cross-well surveillance.

Integration of Post-Fracturing Spectral Noise Log, Temperature Modeling, and Production Log Diagnoses Water Production and Resolves Uncertainties in Openhole Multistage Fracturing

Hydrocarbon development from tight gas sandstone reservoirs is revolutionizing the current oil and gas market. The most effective development strategy for ultralow- to low-permeability reservoirs involves multistage fracturing. A cemented casing or liner completed with the plug-and-perf method allows nearly full control of fracture initiation depth. In uncemented completions equipped with fracturing sleeves and packers, clearly identifying the fracture initiation points is difficult due to lack of visibility behind the completion and long openhole intervals between packers. Also, the number of fractures initiated in each treatment is uncertain. A lateral was completed with access to 3,190 ft of openhole section across five fracturing stages in a high-temperature and high-pressure tight-gas interval. All stages were successfully stimulated, fracture cleanup flowback was conducted, and entry ports were milled out. A high-definition spectral noise log (SNL) was then conducted along with numerical temperature modeling. Additional logging was done with a set of conventional multiphase sensors. A multi-array production log suite was also performed. Finally, the bottom four stages were isolated with a high-temperature isolation plug based on the integrated diagnosis. The SNL helped to analyze the isolation packer integrity behind the liner. The initiation of multiple fractures was observed, with as many as nine fractures seen in a single-stage interval. A correlation was found between the openhole interval length and the number of fractures. A correlation of fracture gradient (FG) and initiation depths was made for the lateral in a strike-slip fault regime. The fractures were initiated at depths with low calculated FG, confirming the conventional understanding and increasing confidence in rock property calculations from openhole log data. SNL and temperature modeling aided quantitative assessment of flowing fractures and stagewise production behind the liner. Multi-array production logging results quantified the flow and flow profile inside the horizontal liner. The production flow assessments from both techniques were in good agreement. The integration of several datasets was conducted in a single run, which provided a comprehensive understanding of well completion and production. High water producing intervals were isolated. Downstream separator setup after the isolation showed a water cut reduction by 95%. The integration of the post-fracturing logs with the openhole logs and fracturing data is unique. The high-resolution SNL provided valuable insight on fracture initiation points and the integrity of completion packers. Fracturing efficiency, compared to the proppant placed, provides treatment optimization for similar completions in the future.

Unlocking By-Passed Oil with Autonomous Inflow Control Devices Through an Integrated Approach

In a giant offshore UAE carbonate oil field, challenges related to advanced maturity, presence of a huge gas-cap and reservoir heterogeneities have impacted production performance. More than 30% of oil producers are closed due to gas front advance and this percentage is increasing with time. The viability of future developments is highly impacted by lower completion design and ways to limit gas breakthrough. Autonomous inflow-control devices (AICD's) are seen as a viable lower completion method to mitigate gas production while allowing oil production, but their effect on pressure drawdown must be carefully accounted for, in a context of particularly high export pressure. A first AICD completion was tested in 2020, after a careful selection amongst high-GOR wells and a diagnosis of underlying gas production mechanisms. The selected pilot is an open-hole horizontal drain closed due to high GOR. Its production profile was investigated through a baseline production log. Several AICD designs were simulated using a nodal analysis model to account for the export pressure. Reservoir simulation was used to evaluate the long-term performance of short-listed scenarios. The integrated process involved all disciplines, from geology, reservoir engineering, petrophysics, to petroleum and completion engineering. In the finally selected design, only the high-permeability heel part of the horizontal drain was covered by AICDs, whereas the rest was completed with pre-perforated liner intervals, separated with swell packers. It was considered that a balance between gas isolation and pressure draw-down reduction had to be found to ensure production viability for such pilot evaluation. Subsequent to the re-completion, the well could be produced at low GOR, and a second production log confirmed the effectiveness of AICDs in isolating free gas production, while enhancing healthy oil production from the deeper part of the drain. Continuous production monitoring, and other flow profile surveys, will complete the evaluation of AICD effectiveness and its adaptability to evolving pressure and fluid distribution within the reservoir. Several lessons will be learnt from this first AICD pilot, particularly related to the criticality of fully integrated subsurface understanding, evaluation, and completion design studies. The use of AICD technology appears promising for retrofit solutions in high-GOR inactive strings, prolonging well life and increasing reserves. Regarding newly drilled wells, dedicated efforts are underway to associate this technology with enhanced reservoir evaluation methods, allowing to directly design the lower completion based on diagnosed reservoir heterogeneities. Reduced export pressure and artificial lift will feature in future field development phases, and offer the flexibility to extend the use of AICD's. The current technology evaluation phases are however crucial in the definition of such technology deployments and the confirmation of their long-term viability.

Insights into Khuff Oil Rim Development in Sultanate of Oman from Extensive Drilling and Well Testing Operations

The Yibal Khuff project is a mixed oil-rims, associated gas, and non-associated gas development in highly fractured tight carbonate reservoirs. Rock types and fractures vary widely with significant contribution to flow. In the east segment of the field, 22 horizontal oil producers targeting K2 reservoir have been pre-drilled and tested extensively. The integration of well logs, borehole image data (BHI), well test data and production logs provide key insights into reservoir productivity and the development of a robust well and reservoir management plan, ready for start-up of the field in 2021. A log-based approach was used to classify the reservoir into three main rock types (RRT). Fractures were classified, and high impact fractures were identified. Reservoir flow profile based on noise and temperature logs was established and used in combination with fracture data and cement bond logs in understanding flow conformance and behind casing flow. A large variation in productivity index has been observed, from tight to highly productive wells. Different ways have been explored to establish the link between productivity index, fracture production, and matrix production by rock types. This is the first full field development in the Khuff formation in Sultanate of Oman. The results will benefit a wider audience. A holistic approach was taken to explore the link between well deliverability and nature of a complex geology. The outcome is a robust operating envelope and well, reservoir and facilities management (WRFM) plan, clearly driven by understanding of subsurface risk and opportunities.

A World-First: 3-Legged Lateral with Smart Completion, Smart Liners and Inflow-Tracers Across Low-Permeability Multi-Stacked Reservoirs

In a giant, mature UAE offshore field, consisting of complex multi-stacked heterogeneous reservoirs, the western part has been less developed, due to contrasted reservoir properties and low-permeability layers. The development in that part of the field was re-visited, to account for reservoir challenges and surface limitations. The objective was to achieve production mandates, understand reservoir behavior, while minimizing well count and expenditures associated with interventions and surveillance activities. To evaluate this challenging area of the field, a unique multi-lateral well was designed, targeting three distinct reservoirs, and allowing to concurrently produce and understand them in a viable manner. The reservoirs have poor characteristics, with permeability lower than 10 mD, except for the deeper one, which has some high permeability streaks. Accounting for the tight formations, each horizontal leg had to be stimulated efficiently, despite being inaccessible with coiled-tubing. In addition, well production had to be reliably back-allocated to each drain, and meet pre-defined reservoir guidelines. Despite contrasting properties, all three drains had to be produced at reasonable rates, avoiding that one drain would dominate the other two. And finally, enhanced reservoir understanding was required within each drain, with qualitative indication of their flow profile and associated reservoir conformance. The 3-legged multi-lateral oil producer was drilled and completed successfully. In each of the three horizontal laterals, totaling more than 15,000 feet length, drop-off limited-entry ‘Smart Liners’ were installed, to allow bull-heading stimulation. This offered an effective high-volume matrix acidizing method, adapted to the contrasted properties and tight zones encountered along the laterals. The well was equipped with permanent downhole gauges and inflow control valves (ICV's) to dynamically monitor downhole contributions, modulate production from each drain, avoiding well delivery to be dominated by the highest potential reservoir and control unwanted water/gas production to the surface. To complete the picture, chemical in-flow tracers were installed, in the tubing and within each drain, to monitor the laterals’ flow profiles and performance, and measure the individual contribution from each reservoir. This aimed to determine the efficiency of the ‘Smart Liners’ design and proved a cost-effective option to quantify the contribution from the laterals, compared to running regular PLTs. The resulting pilot is the first well in the world to combine a smart completion with three limited entry ‘smart liners’ utilizing drop-off technique and chemical inflow tracers. The pilot well, which behavior is being evaluated over 2021, provides a groundbreaking approach to evaluate and unlock hydrocarbon resources in a poorly developed area of the field, allowing a significant optimization of well count and of associated capital and operating expenditures.

First Permanent Inflow Monitoring Experience in a Smart-Liner, Intelligent-Completion, Multi-Lateral Adnoc Offshore Well

The scope of this paper is to share a field experience with permanent inflow tracer deployment and monitoring of an intelligent multi-lateral well, completed with Smart-Liner (Limited Entry Liner). It will describe what ADNOC Offshore has learnt through inflow tracing clean up surveillance from several restarts and steady state production through inflow modelling interpretation techniques. This passive method of permanent monitoring technology utilizes chemistry and materials expertise to design tracers that release signature responses when they come into contact with either in-situ oil or formation water. The chemical tracer technology enables wireless monitoring capabilities for up to five years. Unique chemical tracers are embedded in porous polymer matrix inside tracer carriers along select locations in the lower completion to correlate where the oil and water is flowing in a production well. Interpreting tracer signals can provide zonal rate information by inducing transients to create tracer signals that are transported by flow to surface and captured in sample bottles for analysis. The measured signals are matched with models through history matching to yield zonal rate estimates. ADNOC Offshore has installed inflow tracers in an intelligent multi-lateral well to monitor laterals’ contributions, to verify new completion technology, and to estimate the flow profile from individual sections of Smart-Liner, run for the first time in the field. The interpretation results have been able to characterize inflow performance without any intervention in the well. Several restart and steady state surveys are planned to understand some key characteristics of the well completion and reveal how the well has changed since it was put on production. This technology will help allocate commingled production to the three laterals. The use of inflow tracers will provide multiple inflow surveys that will reduce operational risk, well site personnel, costs and will improve reservoir management practices. Permanent inflow tracing is expected to change the way production monitoring can be performed, especially in advanced wells where PLTs or Fiber Optic technology cannot access multi-laterals.