bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fracture Modeling in Naturally Fractured Reservoir Using Damage Mechanics Coupled with Poromechanics
Authors: Bubshait Ahmed , Aminzadeh Fred , Jha Birendra 
Published: November 2017

Abstract
Presence of natural fractures in reservoirs increases heterogeneity and modeling complexity while playing a significant role on well productivity and field recovery. Placing horizontal wells in naturally fractured tight carbonate reservoirs is extremely challenging due to the large variation in the natural fracture density and consequently in the formation permeability. To enhance and maintain production from such reservoirs, hydraulic stimulation is conducted to create new fractures and activate pre-existing natural fractures. However, during production/injection periods, poromechanical properties of the fractured reservoir might change with changing pressure and stress conditions. This affects ultimate recovery and results of future well placement and stimulation efforts. Changes in the properties, such as enhancement or reduction in permeability, also complicate computational modeling and performance forecasting of the reservoir. In this paper, we propose a framework to capture such flow-induced property changes in a fractured reservoir.
Our framework is based on a sequential solution of three coupled problems: (1) mechanical deformation (2) fluid flow, and (3) fracture propagation. We use the finite element method to solve the quasi-static mechanical deformation problem, the finite volume method to solve the Darcy flow problem in the matrix, and a damage mechanics approach to model propagation of pre-existing spatially distributed fractures and the ensuing evolution in flow and mechanical properties of the reservoir. We use the fixed strain scheme to couple the mechanical problem with the flow problem sequentially. The two problems are coupled to the fracture propagation problem via stresses, pressure, elastic moduli, and permeability.
The framework allows for coupled flow, deformation and damage in fractured reservoirs without the computational burden associated with an explicit fracture representation. This means we can obtain accurate predictions in realistic scenarios of production from heavily fractured and stress-sensitive reservoirs. Modeling these processes will also help in optimizing horizontal well placement decisions.
Improved Field Development through Timely Integration of Post-Drill Analysis Results
Authors: Obeta Chukwudi , Aljaberi Fatema , Khouri Naeema , Al Zawa Hesham Abdulla , Wendland Corey , Dedmon Russell , Al Dhaleei Omar , Ottinger Gary , Shekhar Ravi , Omura Taihei , Al Zinati Osama , Abousayed Nada , Almurshidi Saja , Khan Mohammad Yunus , Attalah Khaled , Al Neyadi Abdulla , Al-Shehhi Budoor 
Published: November 2017

Abstract
As part of the ongoing development of a large offshore oil field, an asset owner places a strong emphasis on continuous improvement of the established framework for integrated post-drill well analysis. The geology of the candidate field is complex and the occurrence and distribution of the extreme permeability features that dictate early water production is highly uncertain. While much effort is devoted to mitigating their adverse impact through proper integration of surveillance data for accurate well planning, post-drill outcomes can still diverge significantly from pre-drill expectations. Several wells have been drilled in the production build-up campaign, including ground-breaking pilots and many more are following in very quick succession as part of the life cycle strategy for the field. Due to high drilling frequency, the challenges of assimilating learnings through conventional post-drill analysis for optimization of future drill wells can be enormous. To apply key lessons from these wells in building quick baseline knowledge for reservoir model update and drill plan optimization, the modeling and development team have developed an improved workflow for integrated post-drill analysis. The workflow leverages the full benefit of collaboration between multi-disciplinary teams to integrate 3D seismic data, multiple well information (including geologic reports, well logs and petrophysical results) and surveillance data from new drill wells to benchmark pre-drill expectations. An important aspect of the approach is the quick incorporation of drilling results into static and dynamic models via a cycled, closed-loop workflow for quick assessment of model fidelity through an evergreen update process. A multifunctional post-drill analysis facilitates critical consideration of well results to capture significant learnings that influence future drill well and data acquisition optimization, reservoir model history match and prediction enhancements, and identification of drilling hazards and geological features that affect reservoir performance. This paper describes the methodology used to plan and implement post-drill well analysis within a fast paced and high drill frequency environment. Key elements of the methodology are described through the use of a case study example, and include: Standardized subsurface workflow, comparison of post-drill well results with pre-drill well expectations, identification and documentation of significant observations and lessons learned improvement of history match & predictive capability of reservoir models and integration with other drill-well delivery processes.
Optimizing Well Design and Real-Time Drilling Operations Using a Seismic Attribute Guided Methodology
Authors: Liang Xing , Zhao Chun Duan , He Yong , Bouchet François , Liu Cheng , Wang Lizhi , Li Qingshan 
Published: November 2017

Abstract
This paper presents a seismic-attributes-guided method developed to assist drilling engineering both at design and execution stages.
In recent years, shale gas has been a focus of development in the Sichuan basin (southwest China). The formations are over 400 million years old; they have been affected by multiple major tectonic events during geological times. As a result, of successive stress and strain, the reservoir rocks now display a large number of small-scale faults, folds and multi-directional fractures. To maximize the value from wells, while avoiding drilling hazards, a detailed structural delineation is required for: reservoir-scale geosteering, well trajectory control and drilling risk prevention and mitigation.
Seismic is the only data available for 3D structural characterization. For an accurate result, high fidelity seismic (amplitude preserved high resolution data) is required. First a pre-stack data is selected (from gathers), conditioned and prepared as a micro cube for interpretation. Then a reservoir scale structural interpretation is carried out and a detailed structural map constructed, to analyze micro structural features from surface based attributes (amplitude, dip, curvature, etc.). In parallel multiple volume attributes are derived from the micro cube, including: variance, Ant-Tracking, apparent polarity and instantaneous bandwidth. In a final step surface attributes and volume attributes are integrated along with the planned well path to help anticipate possible drilling risk. ‘Ant-Tracking’ and ‘Seismic Discontinuity Planes’ algorithms were used to extract fault planes. The apparent polarity attribute reveals the sign of the reflection coefficient; it was found useful for delineating small events. Instantaneous bandwidth, represents the standard deviation of the instantaneous power spectrum about its mean, delineating vertical variation along the structural surface.
We were able to predict drilling risk and formation dip with the integration of seismic attributes.
The predictions were in good agreement with drilling events observed in the horizontal wells, such as: tight pull; mud loss; stuck pipe and drilling breaks. The predicted formation dip trend was confirmed. In one well, the original structural interpretation showed only one fault while the attributes analysis showed 11 faults. While drilling the well, for two of these faults, "bit drops" of 0.5m and 0.1m were observed. Only two predicted faults had no corresponding drilling event, but larger rock fragments were observed in cuttings, suggesting faulted zones may have been encountered.
This paper is based on several real-time-tracked horizontal wells, drilled with the assistance of integrated seismic attribute analysis (including particularly apparent polarity and instantaneous bandwidth).
Reducing Operational Flaring through ALARP Based Decision Making
Authors: Agrawal Harshit , Al Shuayli Mohammed , Salmani Mohamed 
Published: November 2017

Abstract
Long term operational flaring leads to significant loss of gas resources, impact environmental air quality, as well as affect the organization's reputation. Global benchmarks indicate that operational flaring can lead to losses of more than 2% of total oil and gas production. The objective of this study is to present an innovative decision making framework and best practice tool that enables robust cost-benefit risk analysis to be conducted for reduction of long term operational Flaring.
In this study, a state of art, user friendly assessment tool is developed to demonstrate that Flaring risk is reduced to As Low As Reasonably Practical (ALARP). This tool brings greater visibility and ownership of flaring performance by applying a consistent, value based decision making framework for operational flaring events. The framework includes process for derogation, evaluation and investigation of flaring events, taking into account the economic and environmental costs of flaring by monetizing actions such as taking a decision to defer oil production in order to avoid flaring or alternatively taking a decision to flare to maintain production.
The successful roll out of a consistent derogation process through the decision making framework and tool brings management visibility of the cumulative economic and environmental implications of short and long term operational flaring events. This shared understanding in the organization of the decision criteria and thresholds, in longer term leads to significant quantitative reduction in flaring volumes. Secondly, the methodology provides an auditable demonstration of management of Flaring risk to company's internal and external stakeholders.
Additionally, the information gathered from the derogation framework leads to the identification of corrective operability or reliability measures needed to address repetitive non-routine flaring events that will help in continuously driving improvement in longer term greenhouse gas intensity performance and gas conservation priorities.
Dynamic Wellbore and Near-Wellbore Clean-Up in Wells with a Sandface Flow Control Completion
Authors: Nikjoo Ehsan , Mammadov Rufat , Muradov Khafiz , Davies David 
Published: November 2017

Abstract
This paper presents a comprehensive analysis of the well performance during clean-up when the well is equipped with either autonomous, passive, or active sandface flow control completion (sFCC). Numerical modelling is used to study this performance. A few studies have investigated the clean-up performance of sFCCs, especially of the autonomous sFCCs.
The sFCC clean-up performance is modelled using an integrated, numerical simulation of dynamic flow processes in a coupled wellbore-reservoir model. The well model is first saturated with the drilling and completion fluids by considering the effect of the mud cake formation and lift-off pressure during well flow back, as well as the relative permeability hysteresis of the invaded zone. The sFCC's performance is modelled and verified using published input data. The simulations reveal how the various sFCC types differ in their clean-up performance, including:
The sFCC equipped with Inflow control devices (ICDs) can accelerate the clean-up process compared with conventional (i.e. no sandface flow control) completion. The clean-up efficiency of this sFCC type rests on balancing the positive effect of the more uniform inflow profile along the completion and the negative effect of imposing a higher pressure drop across the completion. The sFCC equipped with Interval control valves (ICVs) allows sequential clean-up of the well zones, where the clean-up of each zone can be optimised separately. Finally, the clean-up performance of the sFCC with autonomous flow control devices (AFCDs) is more complex being highly sensitive to this sFCC's design, the extend of the invaded zone, the wellbore trajectory and etc.
Finally, a generic discussion on how to possibly improve the sFCC clean-up is presented. This work improves our understanding of the clean-up performance of wells with sFCCs.
Automated Catwalk Machine for Land Rigs
Authors: Loeyning Trond 
Published: November 2017

Abstract
In the land drilling market there is a lack of versatile catwalk machines. The tradition of having various models for each rig type and drill floor heights makes the typical catwalk machine inflexible. As an answer we have developed a complete new catwalk machine that suits a great variety of rig types and drill floor heights, and the unique design optimizes the angle the pipe enters into drill floor. In addition the optional crane function ensures catwalk versatility and simplifies handling of objects between ground level and drill floor.
Automated operations will lead to self-running operations and ultimately an autonomous drilling operation, thereby allowing drillers to optimize safety and performance. This automated catwalk provides a mechanization that allows remote automatic operation to enable workerless handling of tubulars from ground level to the drill floor. Through our unique design we will not only transport tubulars from ground level to drill floor, but provide a safe and efficient way of handling objects such as stabilizers, subs, bits, and pups between ground level and the drill floor simplified through use of an optional integrated manipulator arm.
An Integrated Approach to Optimize Monthly Production Allowable in a Giant Offshore Field
Authors: Zhao Wenyang , Al-Neaimi Ahmed Khalifa , Saif Omar Yousef , Al-Feky Mohamed Helmy 
Published: November 2017

Abstract
To optimize oil production and improve operating efficiency is always pursued by oil operating companies. It is a very challenging practice to achieve an optimum monthly production plan, especially for a mature oil field with limited surveillance data and increasing challenges. As one of the biggest offshore fields in the world, it has more than 350 oil production strings and more than 200 injection strings. Complicated fluid movement, unevenly pressure support, and no available artificial lift methods are constraining the reservoir capacity. Planning for all these strings used to be a very complicated process.
The presented approach integrates well performance, pressure support, and operating efficiency in order to optimize monthly production allowable. A workflow is embedded into an in-house developed tool, which ensures the correct approach to be applied and also increases work efficiency. The proposed approach enables a proper determination of technical rate for each string with respecting well performance and reservoir management limitations. Automated quality assurance is implemented through the process to avoid human errors due to the heavy number of strings. Efficient Voidage Replacement Ratio (EVRR) on both reservoir and segment levels has been applied to assure proper pressure support. EVRR only takes into account the effective water support from the peripheral water injection. Planned and actual production losses are both included for tracking the production efficiency.
The tool simplifies the process. The application of the tool has significantly reduced the working load and increased the accuracy of monthly production allowable. Well performance of each string has been highly respected in order to maximize oil recovery in a long term perspective. Pressure support on both reservoir and segment level has been achieved on a monthly basis. Besides, the tracking and comparison of the production efficiency could identify the unplanned production losses, as well as the potential production gains by optimizing production and activities plans, for instance, aligning reservoir surveillance plans and maintenance shut downs.
Use of a Novel Coiled Tubing Real-Time Downhole Flow Measurement Tool to Evaluate Matrix Stimulation Treatment for the First Time Worldwide
Authors: Cedeño Ramiro , Thwaiqib Ibrahim , Ahmed Danish , Sa Rodrigo 
Published: November 2017

Abstract
This paper discusses the first worldwide use of a novel coiled tubing (CT) real-time downhole flow measurement tool to evaluate the effectiveness of a matrix stimulation intervention performed in a salt water disposal (SWD) well by comparing the acquired data with the injection profile obtained via a conventional production logging tool prior to the treatment.
When SWD wells show a decrease in injectivity, the operator’s preference is to conduct stimulation treatments or reperforate target intervals before deciding on a costly workover operation. The decision to intervene is often made based on injection profiling performed using production logging tools along with injectivity index calculations. This evaluation represents an additional expense that typically requires significant time and logistical coordination. Alternatively, a CT real-time downhole flow measurement tool can be used to conduct, in a single run, i) injection profiling, enabling optimization of ii) treatment execution, before iii) conducting post-stimulation injection profiling to evaluate the effectiveness of treatment.
With the recent introduction of the CT real-time downhole flow measurement tool to facilitate the optimization and evaluation of matrix stimulation treatments, new concerns arose as to whether an actual correlation existed between said tool and existing injection profiles obtained through conventional production logging tools. Until now, there have been no field data to compare both approaches. During a recent matrix stimulation treatment on a SWD well, it was decided to perform a correlation between the data acquired by both tools before the execution of the acid stimulation. The correlation between the injection profiling obtained via the CT real-time downhole flow measurement tool and the injection profile obtained via production logging tool was remarkably similar. Additionally, it was confirmed during the treatment that the data acquired by the CT real-time downhole flow measurement tool can be further used to optimize the stimulation treatment, before performing another injection profile after the stimulation. Surface and downhole parameters acquired during the treatment were also used to model the well performance via nodal analysis.
The paper shows the world’s first example of the correlation of the injection profile obtained by the CT real-time downhole flow tool to the injection profile obtained via a production logging tool. This paper sheds light on the benefits of monitoring downhole parameters during CT acid stimulations. It also highlights the added value brought by the CT real-time downhole flow measurement tool and how its output correlates to production logging tool data.
Understanding ESP Performance in Multiphase Flow Condition in SAGD Production Wells
Authors: Shang Song , Bustamante Nicolas Gomez 
Published: November 2017

Abstract
High-temperature electric submersible pumps (ESPs) have enabled operators to lower the well drawdown and achieve higher production rate in steam-assisted gravity drainage (SAGD) wells. While theoretically the SAGD process should deliver a single-phase producing stream to the ESP system when bottomhole pressures are reduced to near steam saturation pressures, steam flashing could occur which can result in ESP performance deterioration and wellbore flow regime instability. The essential questions being asked for ESP performance in such SAGD multiphase condition are to identify the boundary at which the ESP and well behavior changes from stable to unstable operations (when is it happening), to determine the effects on ESP deterioration (what are the effects), and to develop solutions to maximize well drawdown with improved well stability (how to manage it).
In this paper, authors will present a new approach to understand ESP multiphase challenges in SAGD operations by using detailed fluid characterization and hydraulic models. The analytical approach identifies phase boundaries (phase envelope), calculates gas-water vapor volume fraction (GWVF) and predicts flow regimes as a function of surface and downhole flowing measurements.
Authors used Soave-Redlich-Kwong for the equation of state (EOS) with the Peneloux volume shift option to compute compositional model and construct pressure-temperature phase diagram for SAGD producing bitumen-gas-water mixture. By coupling the compositional fluid model with a well hydraulic model, one can calculate GWVF and phase splits along the production path and therefore predict flow regimes both upstream and downstream of the ESP. One can also perform pump stage by stage calculations and analyze the pressure contributions as operational stability changes. ESP design and operational recommendations to improve operational stability based on calibrated well model will also be discussed and evaluated in this paper.
Shedding the First Light on the Shilaif Source Rock in the Syncline, Onshore Abu Dhabi, UAE
Authors: Dasgupta Suvodip , Raina Ishan , Povstyanova Magdalena , Laer Pierre Van , Baig Muhammad Zeeshan , Casson Neil , Marzooqi Hassan Al , Suwaidi Salama Jumaa , Ali Humair , Subbiah Surej Kumar , Mello Ashish D’ 
Published: November 2017

Abstract

Objectives
Conventional oil from the prolific carbonate reservoirs of Abu Dhabi has been produced over half a century from different anticlinal structures. Now, the time is right to go back to where it all started- the source rock in the depths of the syncline. The first well in the syncline provided an opportunity to characterize the reservoir quality of Cretaceous Shilaif Formation and understand the potential of the unconventional source rock oil play in Abu Dhabi.

Methods
The carbonate source rocks of Abu Dhabi are very different from the unconventional source rocks in the rest of the world and require a unique approach. An integrated workflow combining log, core and surface measurements has been carried out to characterize the Shilaif formation in the syncline in the south-western part of Abu Dhabi. Every measurement has a distinctive value and helps reduce uncertainties about Reservoir Quality. A critical examination of different available technologies was carried out to examine and optimize the characterization program to understand and reduce all uncertainties about reservoir quality.

Results
The Shilaif source rock in this syncline to the south west of Abu Dhabi is a carbonate-rich organic mudstone, which distinguishes itself by lack of clay and vertical heterogeneity. It is a hybrid source rock with simultaneous presence of both organic and inorganic pores. The extensive core analysis program provided insights about porosity, permeability and saturation, which were used to validate the log interpretation. Higher thermal maturity and stronger compaction lead to different reservoir qualities than the ones previously recognized on the nearby shallower anticlinal structures. The reservoir quality of Shilaif in the syncline (levels of oil saturation, producible pore-sizes and permeability) exceed the pay criteria known to be required to produce economic volumes of oil in other basins around the world. Geomechanical characterization shows that the rock is extremely compact and requires careful planning with respect to proper completions and appropriate fracturing strategy for this play to be successful

Novel Information
This is the first well in the syncline, targeting the mature source rock of Shilaif, based on previously existing literature. This paper explains the interpretation methodology workflow, that integrates all the measurements and discuss for the first time about viability of Shilaif as an economic source rock oil play in UAE, focusing on the syncline.