bluuebunny/crossref_metadata_2025_split huggingface dataset:
Innovative Method of Getting Multiphase Inflow Profile from Fiber Optic Installations
Authors: Kortukov Dmitry , Shako Valery 
Published: November 2019

Abstract
Fiber Optic provides massive amount of information from downhole of the well. The main challenge, however, is to extract the value out of these measurements, which can be used to further improve efficiency of field development. There were number of various methods/workflows developed to provide such conversion. But all the workflows shared the same problem – high ambiguity of interpretation. This is the main cause, why Fiber optic systems were not accepted as reliable multiphase inflow profile measurement.
To address this challenge, innovative method of distributed temperature interpretation was developed. It is based on the fact, that any short term transient events in the well, such as production rate change, will create dynamic temperature change. Such dynamic temperature change is sensitive to specific flow and phase content of flow, and as such, can be used to convert temperature measurements into multiphase inflow profile.
This paper presents field Application example of this innovative method. It describes workflow of data preparation and interpretation, showing the final result in form of inflow profile along the horizontal producing section, composed of 133 producing intervals.
Unconventional Oil Studies of Shilaif Source Rock in Western UAE
Authors: Tian Wenyuan , Jia Minqiang , Xiao Dengyi , Luo Beiwei , Yang Jianfang , Al Suwaidi Saeed K. , Ji Yu , LV Mingsheng , Shashanka Ashis , Mao Demin , Hu Xinli 
Published: November 2019

Abstract
Unconventional studies of UAE is in the early stage, especially in the western part, where the wells were drilled only for conventional oil & gas, with few unconventional data acquired. Shilaif formation is one of the main source rock of Cretaceous in western UAE. The main lithology of Shilaif are argillaceous limestone, lime mudstone and shale. Source rock geochemical analysis and basin modeling studies of western UAE show good source rock of Shilaif with high TOC, large thickness and high maturity mainly distribute in the south-east part of the study area, which is the high potential area for unconventional oil exploration.
Based on the available 3D seismic data and log data, a series of techniques were used to predict the sweet spots of unconventional oil of Shilaif source rock, which includes the following main techniques: 1. 3D Seismic CRP Gather Conditioning; 2. Petrophysics Modeling; 3. Pre-stack Inversion; 4. Fracture Prediction; 5. Hydrocarbon Prediction; 6. Pore Pressure Prediction; 7. In-Situ Stress Analysis. Based on these techniques, one SW-NE belt of sweet spots were predicted in Lower Shilaif formation of the study area, with thick good source rock, high oil retention, high brittleness, high pressure, medium fracture and medium DHSR.
Mechanistic Optimization of Commercial Gas Dehydration and Natural Gas Liquids Recovery Units
Authors: Dara Satyadileep , AlWahedi Yasser , Berrouk Abdallah , Leyland Simon , El Nasr Adel , Khan Ibrahim , Geuzebroek Frank 
Published: November 2019

Abstract

Objective
This study aims at high-fidelity modeling and mechanistic optimization of gas dehydration and NGL (Natural Gas Liquids) systems of a commercial natural gas plant based in Abu Dhabi, UAE. Scope of the work includes development of models, validation of models with plant data, optimization analysis and real-time validation at the plant site.

Method
In this work, we developed a dynamic model for the gas dehydration system and a steady state model for the natural gas liquids recovery unit. An advanced process simulator that follows equation-oriented approach is employed as the modelling and optimization platform. We first show the comprehensive plant data reconciliation followed by the model validation using the operating data of the years 2016 and 2018, to ensure that the model predictions match the real plant operation. We then present how the mechanistic optimization entity result in the best operating conditions for the natural gas liquids recovery system. We also show the optimization analysis that aims at maximizing the adsorption cycle time for the dehydration unit while minimizing the total heating duty required for the regeneration of the molecular sieve beds.

Results
Optimization analysis reveals a significant increase in the annual net revenue of natural gas liquid recovery unit as a result of modifying various process operating conditions that lead to higher liquid hydrocarbon production and lower operating costs related to steam and refrigeration. Similarly, optimization analysis of the dehydration system indicates that adsorption-step time can be increased to a higher value, which results in significant reduction of regeneration costs.
As a next step, we aim to carry out the validation tests on the plant site to verify and implement the model recommendations in the real plant to verify the model recommendations. We also plan to derive the set of operating guidelines that allow the operators to drive the plant towards optimal operation.

Novelty & Significance
Prevent Cement Strength Retrogression Under Ultra High Temperature
Authors: Zhu Jun 
Published: November 2019

Abstract
The cement strength retrogression is expected for Portland cement when it is exposed to high temperature (&gt;110°C / 230°F) environment. Strength retrogression is defined as a change in the hydration products that can be described as a decline of cement strength at elevated temperatures where decreased strength is observed with increasing time. When strength retrogression occurs, not only is there a reduction in the strength of cement, but also an increase in permeability which compromises zonal isolation and/or pipe support, the operation life span of the wellbore would be seriously influenced. It has been a common practice by adding Silica into the cement to counteract and control cement strength retrogression for many years in oil & gas industry. While as drilling operation becomes more and more challenging and downhole conditions are much more complex than ever before, for example tremendous HPHT and deep-water wells are under exploration which raise the new challenges and technical problems to operators. Facing with such challenges the cement strength is expected to be compromised which may result in failure of zonal isolation and common use of silica to mitigate the retrogression may not be an adequate way to contribute the reliable strength and permeability of cement under such high temperature well conditions (&gt;220°C/430°F) in a long term. For a better zonal isolation and pipe support, it is necessary to come up with a novel solution to address cement strength retrogression in challenging well conditions especially at ultra-high temperatures.
This paper would introduce a unique design additive - CemStal (Cement Strength Stabilizer) to help address the cement strength retrogression problem even under ultra high temperature (320°C/610°F) well conditions. The conventional silica was used to compare with CemStal under different temperature conditions and various density of cement slurries to test their ability to inhibit cement strength retrogression. All tests were using almost same formula except the silica and CemStal which is added to help prevent strength retrogression, the densities of cement slurry varied from 1.35SG (low density slurry),1.88SG,1.90SG (regular density slurry) to 2.65SG (high density slurry) and curing temperatures for the test were 220°C/430°F (high temperature), 320°C/610°F (ultra high temperature), the curing intervals of 2, 7, 28, 49 and 98 days’ results were investigated in this study.
Evaluation of Porosity and Permeability Vertical Distribution of Rudist Carbonate Build Up Platform Identified by X-ray CT and 3D Modeling, Late Cretaceous Cenomanian in Offshore Abu Dhabi
Authors: Yamanaka Motoyoshi , Taniwaki Takashi , Nanjo Takashi 
Published: November 2019

Abstract
We investigated the method of estimating porosity/permeability using X-ray CT, a non-destructive method. Using X-ray CT, a method of estimating the porosity/permeability is particularly developed in sandstone. However, for the carbonate rocks, the internal structure is complicated due to biological origin. This is difficult to recognize the pore space, therefore a method of estimating the porosity/permeability using X-ray CT has not been studied. This study is based on Yamanaka et al. 2018, which clarifies rudist development in side slab core using X-ray CT and 3D modeling. The study uses X-ray CT to observe the internal structure from the view of development of rudist of the 200 feet section of the Well A in offshore Abu Dhabi, and compares the porosity/permeability obtained from CCA (Conventional core analysis) of the same well and same interval.
Based on the 3D modeling of the X-ray CT, two rudist families (Radiolitidae and Ichthyosarcolites) were identified through their morphological characteristics such as inner diameter and shell thickness. A porosity of slab core around 50 feet is about 18% from CCA (Conventional Core Analysis). This slab core is made up of small rudist populations (length and wide size is 15-10mm), inside core confirmed 3D modeling (surface rendering and volume rendering), and calculated porosity is 0.89% from RCM (Reverse Coupling method). It is understood that this difference is dependent on matrix porosity and further investigation in the future is required in order to measure matrix porosity using thin section and micro X-ray CT. With regards to reservoir properties, the porosity is higher in the lower part than the upper part in the core interval. The size of the Radiolitidae could be dependent on the environment and its vertical variation suggests the change of depositional environment. Larger Radiolitidae, which appeared from 80 to 200 feet below the C-T (Cenomanian-Turonian) boundary, suggests a relatively strong wave influence. From a sedimentological point of view, the coarser matrix grain size supports the interpretation of depositional setting. On the other hand, from 30 to 80 feet below C-T boundary, smaller Radiolitidae is dominated. It was assumed that small Radiolitidae could be due to high physical stress under a restricted environment.
This study shows the advantage of X-ray CT image in rudist recognition, based on interpretation of depositional environment and understanding the reservoir property. The result of this study suggests the strong correlation between porosity/permeability and depositional environment (accommodation space) inferred from rudist fossil.
Parametric Study on Wind Fatigue Life of Long Span Flare-Boom Based on Directional Input Parameters to Harris Wind Spectra and Selection of Wind Blocks
Authors: Samant Sachin , Agrawal Rajender , Kamal Faris , Takieddine Oussama 
Published: November 2019

Abstract
Long span Flare Booms are fatigue sensitive. Most of these Flares are also protected by the passive fire insulation and hence inspection of Flare structural joints for signs of fatigue cracking/damage during it's service life can result in high maintenance cost. Fatigue design is governed by selected wind speeds also called as wind blocks. It is also governed by the shape of the wind load spectrum. These two parameters viz wind speeds and wind load spectrum play a vital role influencing fatigue life. Present paper contains methodology for selection of the wind blocks. Selection of the directional dependent input parameters to a wind load spectrum is also discussed. Both these cases are studied independently to get the insight on the fatigue life impact. Ultimate aim is to ensure adequate/sufficient fatigue design life of the Flare with minimum maintenance cost.
Kick Isolation While Drilling - First Field Test of an Innovative Risk Mitigation Technology
Authors: Salomone Andrea , Burrafato Sebastiano , Ricci Maccarini Giorgio , Poloni Roberto , Molaschi Claudio , Huse Arve , Tangen Geir Ivan , Regener Thorsten , Backhaus Oliver , Grymalyuk Sergiy 
Published: November 2019

Abstract
Uncertainty in predicting formation integrity as well as pressure regimes poses significant risks to drilling operations. Several technologies can predict downhole environments in terms of formation strength, kick detection etc., but no solution currently exists for kick isolation. This paper presents an innovative well control and risk mitigation technology that is deployed while drilling and the result of a field test offshore Italy.
The new system is integrated in the bottom hole assembly (BHA), and in case of a kick can shut-in the annulus and the drillstring on demand to confine the influx at the well bottom below the sealing elements. A bypass port that establishes communication with the drillstring and annulus can be opened above the sealing elements to allow adjusting of the mud weight. Downhole pressure above and below the annular seal and inside the string can be monitored in real time. The system is deployed in combination with Wired Drill Pipe to ensure activation and bi-directional communication that is independent of any fluid flow.
The system was run on top of the directional rotary steerable BHA while drilling an 8½-in. hole section. The field test was conducted after drilling more than 500 m of new formation and 90 hours in hole. Prior to the test, the system was pulled to surface for visual inspection. No irregularities were observed. The system was then run back in open hole, activated according to operating procedures and tested by applying pressure into the annulus. The well was monitored and no leakage was observed concluding a successful test. Finally, the bypass was opened, circulation was re-established, and the system was deactivated and then pulled out of hole.
This paper describes the technology features and summarizes the first field test results of a new risk mitigation technology for well control situations. This document also shows how deploying new solutions can help E&P operators improve well control through a cost-effective solution and reduce operational risk in case of formation fluid influx into a wellbore.
Energy Saving Challenges and Opportunities in Upstream Operations using Value Methodology
Authors: Soliman Mohamed Ahmed 
Published: November 2019

Abstract
The objective of this paper is to investigate and analyze energy saving and process optimization opportunities in upstream surface facilities, from downhole all the way to the gas-oil separation plants (GOSPs), using value Methodology. Function analysis was used to identify those functions that can be reduced, eliminated, or synergized, to minimize GOSP operating and maintenance cost.
In this paper, various energy saving and process optimization opportunities in GOSPs were brainstormed, analyzed, shortlisted, simulated, and validated using actual plant data. Process simulation using Hysys was used to model and verify the feasibility of different process optimization opportunities in GOSPs. A 300 MBD production facility was used to benchmark the Hysys simulation model, and to verify the feasibility of these promising energy saving opportunities. All of the successful opportunities were selected, based on their minimum OPEX and CAPEX, using value engineering methodology.
Elastic Property Estimation in Digital Multiporosity/Multipermeability Cores
Authors: Ramsay Travis 
Published: November 2019

Abstract
A rock-physics-based evaluation of elastic properties is examined in a coal core, using a three-dimensional (3D) reservoir simulator with an embedded petro-elastic model (PEM) to facilitate the evaluation of fracture productivity mechanisms. The analysis expedites what-if scenario evaluation at reduced costs compared to laboratory experimentation. The flow rates and capillary pressure are incorporated into a simulated coreflood to assess the effect of production on elastic properties at the core scale. A simulated coreflood is performed using an automated steady-state fractional flow process for mixed rock-type systems, which was developed as part of a process automation controller for a reservoir simulator. The process automation promotes adherence to established laboratory-based coreflooding procedures while optimizing for work process efficiency. Typical steady-state modeling processes are characterized as occurring in the capillary limit (CL) or viscous limit (VL) conditions, which are differentiated by flow velocity and capillary equilibration. The elastic properties are calculated by the reservoir simulator during the simulation, based on two available petro-elastic modeling methods—one semi-empirical and the other explicit, based on simulator parameters. The impact of flow rate, capillary pressure, and production on the elastic properties of a coal core are evaluated by simulated primary imbibition coreflooding with application to coal bed methane (CBM) production. The elastic properties are analyzed directly while also considering a dimensionless elastic property formulation. This dimensionless determination amplifies changes in elastic properties that might not otherwise be observed in the results directly; additionally, it combines spatial and temporal changes into an amalgamated variable. In addition to the spatio-temporal characterization of the dimensionless solution, results also show that it is consistent with the pressure solution over a given interval of simulated time. Differences in simulated coreflooding results are observed, which are driven by disparate flow regimes and applied capillary pressure. The differences are attributed to the CL condition imbibition coreflooding results showing decreased affinity to the wetting phase compared to VL-based simulation results. The flow component of the digital coreflooding results is considered valuable to overall asset productivity management. The evolution of simulated elastic properties in the digital core similarly shows that changes in saturated rock properties develop with specific flow conditions and highlights potential uses for core scale analysis in fracture productivity assessment.
Insitu Investigation of Aging Protocols Effects on Relative Permeability Measurements Using High Throughput Experimentation Methods
Authors: Youssef Souhail , Mascle Matthieu , Vizika-Kavvadias Olga 
Published: November 2019

Abstract
Relative-permeabilities are a first-order parameter to consider when describing multiphase-flows in porous media. Among many other parameters, the core wettability controls the fluids repartition in the porous media at pore-scale, strongly affecting how the fluids can be displaced (i.e. their relative-permeabilities). As the initial core wettability of reservoir sampled cores is rarely preserved, classical SCAL measurements (such as relative permeabilities) may not reflect the rock properties at reservoir conditions. This originate core wettability may be restored in a process referred as ‘core aging’. It is generally done by injecting the reservoir fluids (brine and crude-oil) in the core to equilibrate the rock surface with respect to the oil and brine components. Here, we investigated the effect of two aging protocols (static and dynamic) on wettability restoration, and characterize the aging using oil/water relative permeabilities measured on the core after aging. The two aging protocols were applied on a set of initially strongly water-wet outcrop sandstone samples (Bentheimer). The relative permeabilities were measured using the steady-state method and a state of the art experimental setup (CAL-X) based on X-ray radiographies. The setup is equipped with an X-Ray radiography facility, enabling monitoring of 2D local saturations in real-time and thus giving access to fluid flow paths during the flooding. Aged samples relative permeability curves show clear differences when compared to water-wet relative permeabilities, hence suggesting that the wettability has been effectively altered. However, the two aging protocols were unable to produce the same results. The dynamic aging has led to an inversion of the original relative permeability curves asymmetry, suggesting a strongly oil-wet system, whereas the static aging protocol has altered the wettability to a lesser extent. The differences can be explained by analyzing a 2D saturation maps. In the case of dynamic aging we observed a homogeneous distribution of fluid saturation during fractional flow. On the opposite, the static protocol results in heterogeneous flow paths, confirming that this protocol did not alter uniformly the wettability of the sample and generates a patchier mixed-wettability system.
Mudmat Analysis of Jacket Structure - Case Study
Authors: N Nagaraju , Kumar Chaithanya , Varghese Nitin 
Published: November 2019

Abstract
A jacket structure is designed to support a platform required for drilling and production facilities. The jacket is subjected to complex, multi-directional loading during installation. Overturning moments from wind, current and wave loads are skewed from overturning moments from pile and jacket weight eccentricity. The mudmat geometry can be simple with symmetrical mudmats at the four corners of the jacket base or can be complex due to full rectangular area with an off-center, open, rectangular bay for conductor installation. Mudmat geometry, loads during pile installation and soil conditions combined to produce a challenging overturning stability problem. Equivalent area methods of API RP 2GEO and ISO 19901-4 may not predict the low overturning resistance, and a typical righting moment analysis may not capture the soil-structure interaction. To address the geometry and complex loading, a plasticity analysis of overturning stability was performed and is described herein.
Partial safety factors as recommended by API RP 2GEO, ISO 19901-4 were used to assess stability so that overturning from the jacket dead weight could be treated separately from the wind, current and wave loading. Since the partial safety factors are lower for the stabilizing forces compared to the forces causing overturning moments, the resulting safety factors can be lower. Moment and force equilibrium were imposed, and the minimum overturning safety factor was found. Although the vector sum of the factored loads was oriented away from a principal axis of the mudmat, upper bound plasticity methods were used to investigate kinematically admissible failure mechanisms. The method of analysis easily accounts for irregular foundation geometry and complex, multidirectional loading with varying degrees of uncertainty. The method fills a gap in API RP 2GEO and can be implemented in a simple spreadsheet.
A case study is presented to demonstrate the safety factor variation using API RP 2GEO method and the proposed failure method with varying eccentricity in the gravity loads and overturning moments due to wind, current and wave loads.