bluuebunny/crossref_metadata_2025_split huggingface dataset:
Contribution of Dispersion and Permeability Variation on Propagation of Tracer Concentration in Permeable Media
Authors: Shen Tong , Tian Wei , Moghanloo Rouzbeh Ghanbarnezhad 
Published: November 2016

AbstractThis paper examines the decoupling of small-scale heterogeneity (dispersion) and permeability variation in a two-well tracer injection. Tracer transport in heterogeneous reservoirs is governed by spreading (because of the spatial variability of permeability) and mixing (due to dispersion); the combined effects of these two phenomena can be described at very late times (rarely met in practice) by Taylor's theory of asymptotic dispersion. However, decoupling of the heterogeneities at earlier times (pre-asymptotic) has yet to be evaluated.A systematic approach is presented to study tracer propagation (across all layers) in the absence of any cross-flow for a heterogeneous stratified reservoir. The fraction of layers where tracer transport occurs faster than the dispersion mechanism is determined; this fraction represents layers where channeling may take place. Obviously, the larger the fraction, the lower the sweep efficiency. Next, the analysis is extended to five-spot, using the analogy between streamlines and layers with no-cross flow; decoupling of the convective spreading from small-scale heterogeneity is successfully examined for a heterogeneous quarter five-spot pattern.An accurate prediction of "true" dispersion is an essential step in designing of a successful miscible displacement. It improves production forecasts and, consequently, economic evaluation of the project.
Hybrid Intelligent Decision Support System for Drill Rig Performance Analysis and Selection During Well Construction
Authors: Bello O. , Yaakob A. M. , Gegov A. , Teodoriu C. , Oppelt J. , Holzmann J. 
Published: November 2016

Abstract
Drilling rig selection is one the major bottom line during the development phase of hydrocarbons or geothermal well based on comprehensive consideration of a variety of factors for its purpose. The process of drilling a well is highly cost as it involves hiring a drilling rig and crew for the duration of drilling the well. Problem of drilling rig performance and selection has always been viewed as the most important responsibility during the well design phase of a field development, this is mainly caused due to multiple rig manufacturers in the market that meets the operational conditions but not in accordance most operators design specifications. This solution has always been a complex process as various criteria, known and half known are involved in making final decision. Thus, there is a need for simple, systematic applications/tools that can be used to support the decision making considering a number of selection attributes and their interrelations in making right decisions.
This study proposes a peculiar approach, an intelligent decision support application hybridizing distance based approach (DBA) and an artificial intelligence technique, Fuzzy Technique for Order Performance by Similarity to Ideal Solution (FTOPSIS) that will assist well engineers, E&P operators in contacting multiple appropriate rig manufacturer that will deliver a reliable drilling performance resulting to safety drilling operations, mitigate effect of time delay, environmental friendly and most importantly be economically viable for different application.
Currently, the conventional approach for the selection of appropriate drill rig for onshore operational activities is based on method of exclusion associated with engineering experience and lithology of the field to be developed serving as key drive factors.
In order to make it scientific, both qualitative and quantitative parameters influencing drill rig selections were first established using database management system and was later implemented using both two techniques, DBA and FTOPSIS. However, for the purpose of this study, selected onshore rigs are considered for the hybrid model implementation.
The novelty of this study lies in the application of a hybrid approach to a real E&P industry case. This study has dealt with one of the most important subjects as related to well design planning, providing a better decision for the selection of drill rig using appropriate quantitative techniques. This work also helps to select the best way to proceed in a situation when the outcomes are uncertain.
The proposed tool will also set up a benchmarking process providing a feedback to the rig manufacturers for further improvement of their equipments that account to safety, less environmental impact, minimal NPT and better drilling performance operation.
NEBA Application for Jacket Decommissioning Techniques
Authors: Kanmkamnerd J. , Phanichtraiphop P. , Pornsakulsakdi L. 
Published: November 2016

Abstract
It is increasingly important that decision makers for large capital projects (including development and decommissioning project phases) evaluate all project alternatives to determine the optimal final project configuration. The decision making process must take into account several important aspects including the long-term environmental impact or benefit of various project alternatives. Determination of the optimal project alternative often has long-term cost implications. In recent years, several innovative tools have been developed to streamline and optimize the decision making process. One of those is the use of the Net Environmental Benefit Analysis (NEBA) to determine the environmentally superior project alternative.
Here we utilized an innovative approach to the NEBA process by developing a semi-quantitative model that provides a relative ranking of project alternatives based on the expected environmental benefit. Our use of NEBA includes evaluation of initial project impact, impact recovery rate, and final (i.e., post-recovery) benefit level for each considered project alternative. The NEBA tool utilizes a streamlined approach designed to rely on a consensus scoring approach to various project attributes. The results of the model provide a relative ranking of project alternatives based on their net environmental benefit and irrespective of project cost or other considerations. In this respect, our approach provides a "pure" environmental vision of the project. As a consensus approach it is ideal for use in workshop formats with stakeholders and regulators avoiding lengthy iterations to determine a project outcome.
Our case study is made to rank five different project alternatives for offshore platform jacket decommissioning following evaluation of ten environmental aspects. Specific environmental aspects considered include the physical and chemical quality of air, water, and sediments at the project location. The ecology of marine fish, benthic organisms, mammals, and seabirds are also considered as are impacts to fisheries, coastal and terrestrial ecology. We bounded impact recovery rates to 100 years and evaluated five different recovery slope factors in the NEBA model. Following application of scoring and specific weighting factors to each environmental aspect, a quantitative NEBA score was developed for each project alternative evaluated. The result of our NEBA approach was a quantitative ranking of project alternatives in the context of the environmental benefit of each approach.
Our approach provided a comprehensive evaluation of project alternatives and returned a clear environmentally superior project alternative. The results of this approach provide project development decision makers with a cost effective and efficient tool to make defensible decisions to choose the most appropriate project alternative.
Smart-Water EOR Made Smarter A Laboratory Development
Authors: Ghosh Bisweswar , Sun Lying , Osisanya Samuel 
Published: November 2016

AbstractSmart Water and Low Salinity EOR is established as a techno-economically promising method through laboratory coreflood studies and single well tracer studies in field pilot cases. The method is based on lowering salinity of injected water and spiking of multivalent ions such as Mg2+, SO42−, PO43− ions. Wettability alteration and expansion of electrical double layer are attributed to the trapped oil release mechanism. This however invites the possibilities of induced and aggravated scale deposition if the formation water is rich in divalent cations (as in the case of carbonate formation). The resulting formation damage and reduced well productivity may negate the advantages of smart waterflood. This article presents the outcome of an extensive study, conducted to optimize smart water composition targeting an offshore carbonate reservoir. After quantifying the scaling potential at reservoir condition, a Polyphosphate compound is introduced which arrested the scale precipitation. Through contact angle, interfacial tension, Zeta-potential and drainage studies it is established that new formulation not only has reduced scaling potential but also enhanced ability for oil recovery.
Development of Hydraulic Model for Foam Drilling in Vertical Wells
Authors: Sinde Seydou , Shokir Eissa , Dahab Abdel Sattar 
Published: November 2016

Abstract
Foam is commonly used for UBD (underbalanced drilling) because of its low variable densities; which make adjustment of its densities possible in order to keep control of the circulating bottomhole pressures, and because of its high effective viscosities; which give a superior cuttings lifting and transport ability. Foam is also used to transport formation fluids that enter the borehole while underbalance-drilling. This paper is intended to propose an improved computer program in the VISUAL BASIC language that can be used to better simulate the foam hydraulics for vertical wells. The developed model considers foam as a Non-Newtonian power-law fluid in spite of the dispute that still persists among the researchers. Results of the proposed model revealed that the foam flow is affected by the injection pressures, injection flow rates, bottomhole temperatures, ROP (Rate of Penetration), cutting sizes and densities, fluid influxes and the surface back-pressures. The model also proposes a try-and-error procedure to initially determine the best selections of the injection pressures and the injection rates for both liquid and gas. The model evaluation was tested by running the program on two field wells drilled underbalanced with foam in the Middle East with an absolute average error of less than 2.6 % for the first well and with an absolute average error of less than 10.9 % for the second well.
Injection Allocation in Multi-Layer Water Flooding Reservoirs Using SVM Optimized by Genetic Algorithm
Authors: Li Junjian , Jiang Hanqiao , Liang Bin , Zhou Daiyu , Ding Shuaiwei , Gong Changcheng , Zhao Lijun 
Published: November 2016

Abstract
Water injection is essential during secondary recovery process. For multi-layer reservoir, determining the water absorbing capacity of stratification is a necessary step when we investigate the reservoir's production status and analyze the distribution of remaining oil. It is also the precondition of reasonable measures to boost the production, and to improve the ultimate recovery. In view of the reservoir actual situation is multitudinous, such as water is injected at the bottom while the upper produces, and insulation between layer and layer is very poor which can lead to Interlayer channeling, conventional reservoir engineering methods have been unable to effectively forecast recovery performances. This paper set up a methodology of injection allocation in multi-layers water flooding reservoir with support vector machine (SVM) as the core. Because of the credibility of injection profile and liquid producing profile is the highest of all the materials, the method sets the injection profile data and fluid producing profile as the goal, the permeability, reservoir thickness, injection-production well spacing and injection speed and liquid producing as influencing factors, building support vector, then we establish forecasting model, and allocate the water injection rate to each layer. By comparing the injection profile data which is not involved in the prediction process, we found that the prediction of the support vector machine (SVM) method is close and practical, with high credibility. This paper also compared the results with numerical simulation results of commercial numerical simulation software. It is can be found that the method can accurately reveal the inherent law of oilfield development; it has good adaptability and sufficient accuracy. As the forecasting process taking too long, this paper gives the optimization of SVM algorithm. Due to the parameter optimization process of conventional SVM algorithm carried out by searching grid one by one, it ashows these characteristics: low efficiency, large memory overhead. In this paper, we replace the grid searching parameter optimization process by genetic algorithm in the process of machine learning, Results show that the computation time can be reduced more than 70%.
A Novel Chemical Composition to Consolidate the Loose Sand Formation in the Oil Field
Authors: Mishra Saurabh , Ojha Keka 
Published: November 2016

Abstract
Sand production is a major problem to the petroleum industry. Various methods and techniques including mechanical and chemical methods have been proposed but some have failed and some have been ineffective to control the sand production. In the present study a new chemical composition is evaluated to its ability to consolidate the loose sand by increasing its compressive strength without much loss in absolute permeability
For the present study, an experimental setup is designed to consolidate the sand by injecting required PV of chemical solution into the sand pack. All the experiments are done in both presence and absence of hydrocarbon to insure reservoir condition. Effects of chemical composition, curing time, temperature on compressive strength and retained permeability of the consolidated sand is evaluated. Analytical techniques such as FT-IR, FE-SEM, and TG/DTA are used to study the interaction of chemicals with the silica sand sample. The effect of pressure drawdown and flowrate on the consolidation is also studied.
The present mixture shows better consolidation capacity with an unconfined compressive strength (UCS) of &gt;2500 psi with permeability retention greater than 80%. Thus, the consolidation treatment provides the great compressive strength with such permeability retention so that we can take production economically. The curing temperature and time is optimized as 80°C and 12 h respectively. Analytical technique proves a significant binding at the contact point of the sand particles. The consolidation withstand the differential pressure up to 2700 psi and the critical flowrate was recorded as 151.31 cc/sec. the consolidation can hold the pressure drawdown greater than its compressive strength.
The present study comprises the evaluation of a new chemical composition to consolidate the loose sand at their contact point so that it can withstand the drag forces induced by the reservoir fluids and other induced forces.
A Study of Hydraulic Fracture Geometry Concerning Complex Geologic Condition in Shales
Authors: Zhou Tong , Zhang Shicheng , Zou Yushi , Ma Xinfang , Li Ning , Hao Siying , Zheng Yonghua 
Published: November 2016

AbstractThe Lujiaping shale gas formation in Sichuan Basin, SW China, is 1400m deep and has high dip angles. Moreover, it is also subjected to the strike-slip fault geostress and contains highly developed bedding planes and natural fractures. The complex geologic condition makes the fracturing treatment effect hard to predict. This paper aims to establish a simulation model to predict the created hydraulic fracture geometry so as to provide appropriate stimulation strategy. Based on the discrete element method, a novel three-dimensional fracture propagation model is established. The transverse isotropy constitutive relations are primarily introduced to characterize the layered shale in the high dip angle formation. Then, the model is used to investigate how the hydraulic fracture geometry changes with different parameters, such as in-situ stress distribution, natural fracture density, fluid viscosity, and pump rate. The model is validated through experimental data, which shows the simulation result is in accordance with the experimental observation. Taking the complex geologic conditions as the initial condition and assuming the formation dip angle as 50°, the high differential stress which is the difference between overburden stress and minimum horizontal stress enhances the fracture propagation in the vertical direction. At 5 MPa of differential stress, the increase of fracturing fluid viscosity can reduce the influence of bedding plane on fracture geometry. The increase of pump rate is helpful to decrease the restriction of bedding plane on fracture propagation so as to improve the stimulation effect. In addition, the high density of natural fracture will further enlarge the impact on the fracture geometry. This work is a theoretical study of predicting the hydraulic fracture geometry under complex geologic conditions, which provides the technical guidance for the optimization of the fracturing treatment in Lujiaping shale gas formation.
Thermal Cyclic Stress Reduction in Gas Regeneration Piping System
Authors: Surapapwong Thanis , Chaichanavong Charoenpong , Muangsuankwan Natthasart 
Published: November 2016

AbstractThermal cyclic resulting in alternating thermal stress in pipe has been identified as the primary cause of high cycle thermal fatigue failure. From several literatures, most of which involve nuclear power plant industry, the failure is caused by ageing. The monitoring and assessment methodology has been focused and developed continuously. Conversely, in upstream oil and gas industry, the failure due to thermal cyclic stress in piping system has not much been reported in open literatures.In recent year, at the upstream production platform of PTTEP's Greater Bongkot South Field, there was a gas seeping incident at a regeneration gas piping. The overstress due to thermal fatigue at the weldment was suspected to be one of the root causes of the incident apart from the quality of welding profile. Pipe stress analysis for thermal cyclic condition is conducted to check capability of the piping system to withstand a thermal cycling effect due to overstress in the current operating condition. The thermal cyclic in a regeneration pre-treatment unit is brought into the justified case as it has operated in the large thermal range and possibly failed due to the accumulative repeat of the stresses.The pipe stress analysis result reveals that the existing piping routing has overstress in some locations. The overstress is caused by insufficient flexibility in the piping system. The feasible solutions i.e. modifying the pipe route and modifying the pipe supports are modelized and tested in the study. The final solution is to modify the pipe support as it induces less local stress amplitude in the system and it could be implement with less modification work at site. The solution also provides a margin in the number of operating cycles. Thus, the system is able to operate over 60,000 cycles (as the base case is at 20 years design life) thru approximately 120,000 cycles (40 years) with the current operating condition.
Asset Integrity Management System
Authors: Mirza Faisal , Rezaei Cyrus 
Published: November 2016

Abstract
KOC has focused on Asset Integrity Management System (AIMS) & HSE Management System to enhance process safety & prevent Process Safety Management related incidents & spills. AIMS implementation in KOC facilities started a decade ago & KOC has developed a new PSM group in 2015 to focus on process safety while HSE Group has enhanced the personal safety system / standards / procedures. KOC strives to achieve sustainable Operations Excellence to ensure the followings: (1) PSM incidents are systematically analyzed to identify Root Causes & Critical Factors, (2) Key Performance Indicators (KPIs) are implemented with controls in place to prevent recurrence & monitor progress.
The overall AIMS system comprises (1) well integrity, (2) pipeline integrity and (3) facility integrity with focus on PSM system at present. While the company's HSE management system is more focused on personal & occupational safety, environment protection & behavioural-based safety (BBS), the AIMS/PSM aspiration is to imbed inherent safety in the project design cycle, manage the safety critical equipment (SCE) and aim for sustainable Operations Excellence.
Operational Excellence is at the heart of KOC commitment to HSSE and is integrated & not separate. It also includes a comprehensive Behavioral Based Safety (BBS) implemented in all assets to identify & correct the human error aspects which can emerge as critical factors leading to incidents. The AIMS system implementation commenced under HSE umbrella and is focused on process safety management system (PSM) with relevant policy and procedures. Company operational assets include Wells, Flow lines, Manifolds, Gathering Centres (GC), Booster Stations (BS), Pipelines corridors, Tank Farms, Export & Marine Facilities . Planned Preventive Maintenance (PM) and Inspection & Corrosion activities involve RBI (Risk Based Inspection) of static equipment and RCM (Reliability Centred Maintenance) for rotating machinery.
SPARC: MASS MODELS FOR 175 DISK GALAXIES WITH SPITZER PHOTOMETRY AND ACCURATE ROTATION CURVES
Authors: Lelli Federico , McGaugh Stacy S. , Schombert James M. 
Published: November 2016

ABSTRACT
We introduce SPARC (Spitzer Photometry and Accurate Rotation Curves): a sample of 175 nearby galaxies with new surface photometry at 3.6 μm and high-quality rotation curves from previous H i/Hα studies. SPARC spans a broad range of morphologies (S0 to Irr), luminosities (∼5 dex), and surface brightnesses (∼4 dex). We derive [3.6] surface photometry and study structural relations of stellar and gas disks. We find that both the stellar mass–H i mass relation and the stellar radius–H i radius relation have significant intrinsic scatter, while the H i mass–radius relation is extremely tight. We build detailed mass models and quantify the ratio of baryonic to observed velocity (V
bar/V
obs) for different characteristic radii and values of the stellar mass-to-light ratio (ϒ⋆) at [3.6]. Assuming ϒ⋆ ≃ 0.5 M
⊙/L
⊙ (as suggested by stellar population models), we find that (i) the gas fraction linearly correlates with total luminosity; (ii) the transition from star-dominated to gas-dominated galaxies roughly corresponds to the transition from spiral galaxies to dwarf irregulars, in line with density wave theory; and (iii) V
bar/V
obs varies with luminosity and surface brightness: high-mass, high-surface-brightness galaxies are nearly maximal, while low-mass, low-surface-brightness galaxies are submaximal. These basic properties are lost for low values of ϒ⋆ ≃ 0.2 M
⊙/L
⊙ as suggested by the DiskMass survey. The mean maximum-disk limit in bright galaxies is ϒ⋆ ≃ 0.7 M
⊙/L
⊙ at [3.6]. The SPARC data are publicly available and represent an ideal test bed for models of galaxy formation.