bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bayesian Identifying of Influential Factors Affecting Steamflooding Processes Performance in Heterogeneous Bitumen-Oil Sandstone Reservoir
Authors: Al-Mudhafar Watheq J. , Klimenko Denis 
Published: October 2015

Abstract
The Steamflooding was considered in this research to extract discontinuous bitumen layers and improve oil recovery in the Upper Sandstone Member of South Rumaila Oil Field, located in Southern Iraq. The reservoir heterogeneity and bitumen layers, which are located at the water-oil contacts, impede water approaching into the reservoir from an infinite active aquifer; therefore, Steamflooding came over this situation by efficiently extracting the bitumen. This research focused on using a Bayesian framework of Experimental design with thermodynamic reservoir flow modeling for the purpose of identifying the most influential factors that impact the reservoir performance through Steamflooding processes. Thermodynamic reservoir simulation was used to compute flow response, cumulative oil production, to evaluate the various what-if scenarios that are created by experimental design. Latin Hypercube Sampling was adopted for its discrepancy and uniformity to generate many experimental runs that capture the variety of Steamflooding process evaluation.
The factors that were considered to test reservoir response are steam injection pressure, steam quality, steam injection rate, steam temperature, maximum oil production rate, minimum bottom hole pressure, maximum water cut, skin factor. Additionally, the reservoir properties of horizontal permeability, porosity, anisotropy ratio, aquifer radius, and rock compressibility are included. In order to find out the most influential factors on the Steamflooding performance, Bayesian Model Averaging (BMA) was adopted as model selection in the experimental design in comparison with the conventional stepwise linear regression. Model selection process in BMA considers the model’s posterior probability and Bayesian Information Criterion (BIC). BMA produces a posterior distribution of the outcome factor that represents the weighted average of the posterior distributions of that factor for each likely model. Among multi models, few ones were selected that their posterior probabilities sum equals one. The best model selection has the maximum posterior probability and minimum Bayesian Information Criterion; nevertheless, the reduced model is determined when the non-zero probability of coefficient for a given predictor equals more than 50% for all the sampled models.
All these variables are shown in the computed Occam’s window. The results showed that BMA algorithm has efficiently eliminate the non-influential factors on the Steamflooding performance. The most influential factors on the Steamflooding performance were identified by LHS are maximum oil production rate, maximum water cut, in addition to permeability, porosity, anisotropy ratio and rock compressibility. However, the conventional stepwise regression has shown that porosity is the most influential factor with limited effect for all other factors that is physically meaningless.
Hostile Environment Electric Line Well Interventions Optimize Operations in Kazakhstan
Authors: Etuhoko Mike , Viti Massimo , Zmeyevskiy Sergey , Izbassov Arman , Bersugurov Yerdos , Hutson Peter , Aibazarov Muratbek , Clayton Dave 
Published: October 2015

Abstract
Electro-hydraulic robotic tools that perform well interventions on electric line (e-line) have come of age over the past 10 years and can now be used to accomplish tasks previously done with the use of jointed pipes and/or coiled tubing conveyance system. Examples of such tasks are downhole milling, shifting of stimulation sleeves, etc.
Surface real time monitoring and control features are required to ensure that such tasks done by robotic tools are successfully achieved with high accuracies. As the demand increases to use this type of powered devices in a more hostile well environment, service companies have developed technologies to expand their operating range.
Starting from late 2013, the robotic technology solution has been used in KPO horizontal sour wells to close stimulation sleeves when required for reservoir fluid management, to convey perforation guns, to convey production logging tools and to mill frac balls and ball seats.
This paper will present four case histories of the robotic technology application in the Karachaganak field. It will discuss the advantages of the technologies, the challenges and the future improvement required to further optimize the field operations.
The Hydrodynamic Aquifer Studies in Azeri Field
Authors: Asgarov Murad , Bayramov Jabbar , Mamiyev Vidadi , Ibrahimov Turan 
Published: October 2015

Abstract
The Azeri-Chirag-Gunashli (ACG) oil field is located in the hydrodynamic environment of the South Caspian Basin (SCB). The presence of lateral pressure variations in such systems results in tilted hydrocarbon-water contacts. Besides the tilt, the eastern part of the field demonstrates unexpected fluid contacts observed from several appraisal and development wells. These unexpected contacts are not in accordance with tilts and cannot be explained by hydrodynamism only.
Proposed solution to explain contact anomalies in the eastern part of the structure is to analyze the effects of permeability barriers on fluid contacts in hydrodynamic environment. Analysis is done through mechanistic model simulations. It was determined that barriers influence the contacts in hydrodynamic aquifer environment and it is possible to explain aforementioned contact anomalies by plausible barrier arrangement.
Incorporation of study results into the Azeri full field model (FFM) resulted in better pressure and saturation match.
Absheron Field – ABX-2 Exploration Drilling Challenges and Realizations
Authors: Gautherot Thomas , Bakirov Shaik 
Published: October 2015

Abstract
In June 2009, a PSA was signed for Absheron field by Total Exploration and Production (TEP) Absheron BV, as operator, and SOA (SOCAR Oil Affiliate). Soon after GDF SUEZ E&P Absheron B.V. joined the venture and shared its commitment to drill an exploration well, ABX-2, within the 3 years of the first exploration period. ABX-2 was spudded in January 2011 with the Maersk Heydar Aliyev semisubmersible drilling rig. In September 2011, a major gas condensate discovery was announced. In June 2012, the JV declared the commerciality of the newly discovered Absheron field. ABX-2 well was suspended in September 2012. In 2015, Absheron field development studies are progressing to pre-FEED stage, based on well data from ABX-2.
The South Caspian basin is known to be a prolific oil and gas region but yet a challenging environment for drilling. Absheron structure which lies in 500m water depth with exploration objectives from 5500m to 7000m is no exception. This paper illustrates the challenges that TEP Absheron BV anticipated and faced during the preparation and the execution of ABX-2 drilling program. It elaborates on particular aspects of the mobilization of drilling operations in Azerbaijan including logistical means, rig modifications, as well as the multiple drilling technologies and strategies that were developed at the planning stage to the actual drilling operations illustrating how the drilling solutions permitted management of unexpected situations and to complete exploration objectives.
The paper also demonstrates the value of factoring the potential appraisal strategy (well testing, geological sidetrack) into an exploration well design in order to maximize the appraisal value gathered from the exploration well allowing acceleration of the field development sequence.
Mouse model of ulcerative colitis using trinitrobenzene sulfonic acid
Authors: Rather Irfan Ahmad , Bajpai Vivek K. , Gyeong-Jun Nam 
Published: October 2015

<p>Animal model of intestinal inflammation is of paramount significance that aids in discerning the pathologies underlying ulcerative colitis and Crohn’s disease, the two clinical presentations of inflammatory bowel disease. The 2,4,6-trinitrobenzene sulfonic acid (TNBS) colitis model represents one such intestinal inflammation-prototype that is generated in susceptible strains of mice through intra-rectal instillation of compound TNBS. In this paper, we demonstrate the experimental induction of TNBS-mediated colitis in a susceptible strain of ICR mice. This can be done by the following steps: a) acclimation, b) induction and c) observation. TNBS-mouse model provides the information in shortest possible time and simultaneously represents a cost effective and highly reproducible model method of studying the pathogenesis of inflammatory bowel disease.</p><p><strong>Video Clips</strong></p><p><a href="https://youtube.com/v/6MsuIGzH3uA">Acclimation and induction of TNBS</a>: 4.5 min</p><p><a href="https://youtube.com/v/ya66SNwoVag">Observation and drug administration</a>: 1.5 min</p>
A new species of Cales (Hymenoptera: Aphelinidae) parasitizing Bemisia pongamiae (Takahashi) (Hemiptera: Aleyrodidae) in Taiwan, with a key to world species of the Cales spenceri-group
Authors: Polaszek Andrew , Shih Yuan-Tung , Ward Samantha 
Published: October 2015

The genus Cales has been extensively revised recently and divided into two species groups, the noacki- and spenceri-groups Mottern et al. (2010), Mottern and Heraty (2014).
Cales motterni Polaszek, Shih & Ward sp. nov. is described from two females reared from the whitefly Bemisia pongamiae from Taiwan. The species belongs to the spenceri- group, and has a characteristic and unusual antennal clava. A key to the four species currently known from the spenceri-group is provided.
MOBO ESP Interventions
Authors: Urban A. , Boechat N. , Haaheim S. , Sleight N. , Debacker I. , Rivera Robert 
Published: October 2015

Abstract
The Shell operated Parque das Conchas fields of the Brazilian deepwater block BC-10 utilize ESPs as the sole artificial lift method. Unlike traditional in-well deployed ESP systems, the ten BC-10 ESPs are deployed inside relatively shallow – 100m - caissons distributed across three subsea gathering areas, or Artificial Lift Manifolds at water depths from 1650 to 1900m. The integrated caisson, ESP and inflow/outflow valving is deployed and retrieved as a single unit and hence derives the name of a Pump Module, or Modulo de Bomba in Portuguese, or MOBO for short.
As ESPs have much shorter run lives compared to the approximate 25 year field life, the BC-10 subsea operations asset team is responsible for managing and executing the rig based ESP replacement intervention campaigns, or Mobo interventions. As of 2015, nine ESP replacements have been executed in four campaigns. This paper examines the diverse aspects associated with the ongoing efforts to maintain the artificial lift system of BC-10 before, during and after a rig intervention campaign. Topics covered include the ESP failure analysis, equipment sparing philosophy, equipment and tooling preparations, offshore execution, vendor relationships and overall project management. Finally, learnings obtained during the four years of near continuous preparation and execution of MOBO interventions are discussed along with some planned future improvements.
Feasibility Study on Logistics Hub for Passengers in Offshore Brazil
Authors: Maeda K. , Ohmura T. , Harada H. , Miyabe H. , Sezaki Y. , Takeda S. 
Published: October 2015

Abstract
The optimization of passenger transportation system takes on an increasingly important role in case of the large distance from onshore to offshore floating units. Especially, if number of offshore floating units is large. As a solution of this issue, authors introduce the results of the feasibility study of the Logistics Hub System which aims at the application to offshore Brazil.
The authors investigated the situation of the logistics around the offshore production units based on announced information. In consideration of number of transferred workers, weather conditions in offshore Brazil, daily operation, emergency response and so on, we developed the conceptual design of Logistics Hub System for passengers, which consists of the floating hub unit and high speed vessels. Feasibility and operability of conceptual system were confirmed by numerical simulations, model tests and risk analysis.
Shape of the floating hub is selected semi-submersible type and the high speed vessel is a trimaran type. The floating hub has a berthing area inside of it, and high speed vessel will berth to this berthing area. Feasibility of this berthing operation was confirmed by model tests and maneuvering simulator. Also risk analysis was conducted and design of the floating hub and high speed vessels were considered results of this analysis. The point of view from operability, we checked relative motions between the floating hub and the high speed vessel for safety embark or disembark from the high speed vessel to the floating hub. These results shows the Logistics Hub System for passengers has enough feasibility and operability, and it will able to reduce the operation cost and accidental risk compared with transfer operation by using only helicopters from onshore to offshore platforms. This paper reveals the technical feasibility of the Logistic Hub System in terms of safe and efficient transportation of workers. It will contribute to the future development of oil and gas fields which has large distance from onshore.
Economic Viability of E&P Projects under Production Sharing Agreement: Libra field Case Study in Presalt
Authors: Motta R. d. , Caldas L. Q. , Amaral N. B. 
Published: October 2015

This paper intends to study presalt region economic viability by choosing the case of Libra field, the only presalt field to be acquired in Production Sharing Contracts bid round until now. Libra is considered one of the most important exploratory areas worldwide and its Brazil´s biggest oil field.
For the conclusions of this paper it was necessary to estimate production volumes and costs involved in the development of Libra oil field according to industry parameters and government data. A forecast for oil prices was stipulated according to historical data and future contracts. A cashflow could be determinate by concatenating expected income with production sharing agreement government outcomes, making it possible to define the Payback, Internal Return Rate (IRR), and Net Present Value (NPV) of the investment. Varying the discount rate it was possible to study the NPV sensibility.
The Brazilian new exploratory frontier region denominated Presalt is gaining remarkable importance in country´s economic and political scenario. The outlook for the next 10 years is that presalt fields will represent over 50% of Brazilian´s production, calling attention of researchers and experts. To aim high economic benefits, in such alluring area, local Government presented a series of adjustments in its regulations for E&P industry.
However, drilling and producing in Presalt presents technology challenges, due to significant distances from shore, extreme water depths, thick and unstable salt layers, and still limited knowledge over reservoir rock. Research and appraisal will consume high investments, since technologies to be used in the region involve high costs. Added to this there are uncertainties concerning the current regulatory changes, which constrain production profits, and rise concerns over projects viability in the region.
Large Bore, Extreme Conditions Horizontal Deepwater Connection System
Authors: Watkins D. , Charalambides J. 
Published: October 2015

This presentation will concentrate on the design challenges, experience and learnings from the Oceaneering 22 inch, 5,000 psi horizontal pipeline connection system. The gas development project is in approximately 4,900 FSW and is designed to deliver approximately 330 million SCFM for the next 30 years. The heavy wall jumper piping imparted heavy external loads on the connectors along with the pressure end loads and thermal fluctuations associated with the gas system.
Aspects of the connection system are unique due to the design requirements such as heavy imparted loads during make-up and operation, multiple make/break cycles, and torque tool operations. These and other aspects of the connection system required a new and reformatted approach to existing clamp connector designs.
Sales Gas Production Challenges in an Ultradeep Water Field
Authors: Orreindy S. , Batalla L. F. , Superchi G. 
Published: October 2015

Sales gas production offshore needs a complex process involving low temperature system to condense heaviest hydrocarbons from the gas and spike them totally or partially in the oil stream, while complying with sales oil specification.
This work studies the parameters that impact on this process, the main challenges that can arise and the different ways to deal with them in order to ensure a smooth sales gas production during the whole field life, even with very stringent conditions.
Wellbore Stability Model for Standalone Liner Completed Wells in Carbonate Reservoirs Subjected to Acidizing Jobs - I. Dissolution-Induced Mechanical Weakening Model
Authors: Santos E. S. Raggio , Ferreira F. H. 
Published: October 2015

Mechanical stability analyses are mandatory to identify suitable candidates for openhole completions. These analyses should comprehend the effects of production drawdown and reservoir depletion state anticipated by the production plan. The understanding and modeling of the physico-chemical interactions between rock and flown fluids and their impacts on the rock mechanical properties is imperative in the openhole stability analysis of wellbores drilled in carbonate reservoir rocks, especially in the wells subjected to acid stimulation.
This paper presents a methodology for determining the impact of stimulation jobs in the confined rock mechanical response and thus on the acidized wellbore stability. The authors briefly discuss the main rock dissolution patterns, ranging from compact dissolution to homogeneous, passing through the wormhole generation. The homogeneous dissolution pattern has been pursuit in the laboratory because of: i) absence of confident methods to anticipate which other pattern should be more dominant in a given scenario; and ii) Its highest impact on the mechanical properties, leading to safe analyses.
As a result, 24 samples from an off-shore carbonate reservoir have been mechanically tested. 13 of these have been tested after a massive dissolution. The initial effective pore volume and its evolution due to dissolution have been registered and were applied as a geomechanics indicator. The triaxial test results show that the rock softens during injection with impacts on its kinematic parameters. The ultimate rock strength, otherwise, remained almost unchanged. An analytical expression has been devised to map the porosity variations in the wellbore surroundings based on the acid job operational parameters. It indicates that the main failure behavior of a uncased wellbore subjected to acidizing jobs or non-native fluid flows should be related to excessive near wellbore rock straining rather than brittle failures. In this scenario, a standalone completion scheme would be preferable against the barefoot because of its ability to provide mechanical support to the altered rock at the borehole walls.
The current dissolution-induced rock weakening model presents a significant increase in the understanding on how the acid job affects the carbonate rock mechanical response, building a solid base for the well integrity analyses in the production phase.
The Buoy Supporting Risers (BSR) System: Steel Catenary Risers (SCRs) From Design to Installation of the First Reel CRA Lined Pipes
Authors: Gouveia J. , Sriskandarajah T. , Karunakaran D. , Manso D. , Chiodo M. , Maneschy R. , Pedrosa J. , Cruz I. 
Published: October 2015

Abstract
Steel catenary risers (SCR) have been a favored choice for recent ultra-deep waters field developments subjected to harsh environments and large Floating Production Units (FPU) motions. The design of SCRs in such conditions is always a great challenge where the key issues are the fatigue near the hang-off and at the touch down point; clashing between lines, especially on fields with a large number of wells and high payloads on the production unit. This paper describes the solution provided by the Buoy Supporting Risers (BSR) concept which has recently been installed in the Santos basin offshore Brazil.
Subsea7 detailed the original concept of BSR system, from the design to fabrication and installation. The BSR concept combines several benefits to overcome the challenges of installing SCRs on ultra-deep waters, such as: allowing decoupling between installation of risers/flowlines and the platform, reducing payload on the production unit, very small dynamics transmitted from production unit to the risers, resulting in significant less fatigue issues. Also, the BSR concept reduces the risks associated with clashing and interference due to the smaller dynamics when compared to traditional coupled solutions. Fabrication is also addressed to highlight main challenges associated to assembling and welding clad and lined pipelines.
In order to install Corrosion Resistant Alloys (CRA) lined pipes with a Reel-Lay vessel, a novel methodology for water pressurized spooling and pipelay was developed to mitigate the risk of liner damage during installation. Full-scale pressurized spooling trials were done ahead of the pipelay campaign for testing and validation of this methodology. In addition, analyses were performed to evaluate the BSR system behaviour during SCRs installation and to minimize buoy de-ballasting interventions.
The SCR itself, due to de-coupling of motions by the buoy, have negligible dynamic response from vessel motions, thereby behaving almost like a static system with robust fatigue performance. The only meaningful fatigue in SCRs is due to current induced VIV and is mitigated using strakes. There was negligible potential clashing with adjacent SCRs.
This paper provides a summary of design and qualification work carried for SCRs installed in the BSR system the faced challenges and solutions engineered during fabrication and installation scopes.