bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental Phase Behavior Studies for EOS Modeling in CO2-EOR Projects in the UAE
Authors: Achuliwor N. A. , Williams J. M. 
Published: November 2017

Abstract
This paper presents an experimental approach to minimize uncertainties involved when modeling CO2-crude oil mixtures. Very little data on CO2-crude oil mixtures have been published in the literature, and most do not cover the range of temperatures necessary for a broader interpretation of data during equation of state (EOS) modeling. Also fluid viscosity is rarely measured. This work addresses both issues, and also develops new experimental procedures.
Phase behavior studies of CO2 mixtures with a live oil sample from a UAE field were carried out using three different temperatures (54°C, 64°C and 74°C) and maximum pressure of 4500 psi. CO2 was injected into a cell containing the crude oil at a suitable working pressure of 2500psi, and swelling tests were conducted. Fluid properties such as saturation pressures, crude oil densities, viscosities, relative oil volumes and swelling factors were determined. It was confirmed that the swelling factors increased with a rise in temperature at constant injection volumes. In addition to the phase behavior studies, a modified operating method was developed for the capillary tube viscometer which required approximately half as much sample. The procedure took into account the integrity of the homogenous mixture as well as the dead volumes of the equipment, and gas trapping effects during sample charging. Results obtained from this method were repeatable and consistent with the routine method, with an average deviation of 0.34%. At the final step of CO2 injection in crude oil, a viscosity reduction by a factor of 4.4 was recorded. The method should be beneficial for subsequent research projects involving viscosity measurements of CO2–crude systems.
A commercial software was used in the phase behavior modeling of the laboratory data. The software incorporates the Peng-Robinson equation of state (PR-EOS) for modeling the experimental data obtained for the range of temperatures. The reservoir fluid sample was first characterized into several components, and then the EOS parameters and viscosity model were tuned to match the experimental data. The outcome of the EOS modeling established that the critical properties, binary interaction coefficients, acentric factors and the selection of tuning weights were the most sensitive and influential parameters. An 11 component lumping scheme was found to accurately match experimental data at all three temperatures.
Targeting Secondary Oil Rims GOGD in a Mature 50 Year Old Development in the Sultanate of Oman
Authors: Ferrero M. Boya , Holst M. , Bazalgette L. , Unal E. , Farsi S. , Sheheimi A. 
Published: November 2017

Abstract
The GOGD recovery mechanism in fractured reservoirs consists of taking advantage of gravity to develop the oil stored in the matrix through the management of the position of an oil rim within the fractures, where producers are placed. Gas oil gravity drainage is an effective method to increase ultimate recovery but it is a slow process. After 50 years into the development of a giant oil field in Oman, a new strategy for placement of additional GOGD wells is proposed, with the objective to optimize the performance of specific layers and achieve top quartile performance.
The understanding of a complex fractured field is based on a thorough data analysis phase with a focus on the total picture, the conceptual interpretation of 50 years of history, the successes and the failures, to locate the remaining oil1. The data itself reveals the fluxes of the fluids within the reservoir and the physics of the recovery mechanisms taking place at all scales (mega-scale, meso-scale and micro-scale). The insights on reservoir plumbing have enabled the identification of in-fill opportunities through a better definition of faults & fracture maps and an updated fluid-fill concept (for matrix & fractures) explaining post-production contacts variability.
We have described a new well placement strategy to target parallel GOGD processes happening across scales, and specifically within the background fracture network confined between fault corridors and mechanical shale barriers, in what we call "matrix blocks". Conceptual box models have been constructed to prove feasibility of the new development strategy through dynamic simulation.
The infill development has been phased according to the ranked risk assessment of every specific location and the value of information it can provide for successive phases targeting smaller matrix blocks or more uncertain remaining oil.
Standard GOGD practice in intensively fractured reservoirs is to manage the final position of the fracture oil rim, gas and water contact within the fractures, through managed gas injection and potentially aquifer pump off wells. We hereby propose the infill drilling of additional shorter horizontal wells avoiding major fracture corridors, placed above shales at the bottom of geological sequences to maximise gravity head and fluid hold up at discrete matrix blocks. Such wells are not at field wide final oil rim depth and they do not intend to target matrix sweet spots but rather accelerate the recovery of unfaulted stacked units.
Big Bore Remote Actuated Barrier Device Development and Qualification
Authors: Beaman Daniel , Newton Daniel , Oaland Jarle 
Published: November 2017

Abstract
This development predominantly from four artificial islands of a giant offshore field in the United Arab Emirates (UAE) requires isolation of the reservoir during deployment of advanced ERD upper completions.
This methodology to isolate the reservoir, during upper completions, carries through to rigging down the Blow Out Preventer (BOP) and offline Xmas tree installation operations. These well construction barrier requirements are met with the use of a tubing deployed barrier device and packer within an intermediate completion that is deployed as a separate trip in the hole on drillpipe to isolate the reservoir. Prior to running the upper completion both packer and barrier device are suitably tested to confirm their barrier status.
Current barrier devices utilized in the field development require wellbore intervention with either slickline or coiled tubing to remove the internal barrier in the devices. Both of these methods pose a financial impact and operational risk to the well. In addition, they can cause delays to the rig schedule as the intervention in some cases needs to be done on critical rig path, in situations where the next well on the schedule prevents offline access. Development plans to both minimize current and future wellbore interventions with slickline or coiled tubing, and maximize Inner Diameter (ID) to allow for remedial completion operations, resulted in a requirement for a barrier device with both remote actuation and large internal bore.
The authors describe the process undertaken to develop, qualify and deploy a big bore, Remote Actuated Barrier Device (RABD) to meet the field development requirements.
Integration of Sustainable Innovation in Research and Development Related to Natural Gas Processing
Authors: Singh Prachi , Aggarwal Dinesh , Ahnaish Tasnim , Namjoshi Aditya , Geuzebroek Frank 
Published: November 2017

Abstract
Considering current changes in supply and demand of the oil and gas value chain, it is essential to embed sustainability measures in the business. Research and development plays an important role in achieving the sustainability in natural gas processing. Hence, this work indicates how the sustainability elements economics, environment and social can be embedded in the management of research and development portfolio. A natural gas R&D model is proposed for GASCO from the sustainability angle. Moreover, it will be shown how during the execution of research projects the sustainability aspect needs to taken into account at each stage, from concept definition till deployment of the technology. Several technologies are identified that can be further researched or evaluated for their application in natural gas processing, to eventually enhance the sustainability of current operations.
Modified Starch Gel Foam: Research and Application in Naturally Fractured-Vuggy Carbonate Reservoir
Authors: Qu Ming , Hou Jirui , Wang Qian , Su Wei , Ma Shixi , Yang Tianyuan , Li Pengyang , Bai Yu 
Published: November 2017

Abstract
Tahe oilfield is one of the most important naturally fractured-vuggy carbonate oil fields in China. The characteristics of this type of reservoirs are greatly complex due to its multiple flow units: matrix, fractures and vugs. Gas flooding is a practical way of enhancing oil recovery (EOR) for fractured-vuggy carbonate reservoir. The main problems during gas flooding include the complicated oil-gas relationship and gas channeling rapidly. Gel is an effective measure to control channeling. However, ordinary gel cannot adapt to the reservoir conditions in which salinity is 220000mg/l and temperature is 120°C.
Based on Tahe oil field reservoir conditions, we develop Modified Starch Gel Foam (MSGF) which has the function of salt-tolerance and temperature-resistance on the basis of laboratory experiments. In order to study the static performance, different foam volume and half-life period were recorded by varing temperature, mineralization and pressure. We also observed microscopic morphology and bubble distribution of MSGF. To evaluate the dynamic effect, fractured-vuggy physical model was designed and fabricated to present the dynamic characteristic in fractures and vuggs media.
Experimental results show that the even distribution, similar diameters of bubbles, thick liquid membrane and high viscosity prove MSGF is stable and available in the water with the salinity of 220000mg/l and temperature of 120°C. The liquid membrane including the continuous structure formed by macromolecular gel protects the bubbles from the harmful influence of ions. After the defoaming behavior, the rest solution becomes gel again, which benefits controlling gas channeling. The item which contributes to this phenomenon is proved to be the foaming stabilizer. MSGF was able to control nitrogen mobility and channeling.
Because of the salinity and temperature tolerance, MSGF can be applied in high salinity and high temperature reservoirs, especially in fractured-vuggy carbonate reservoirs. This kind of reservoirs does not have porosity which will make it possible for normal foaming system to foam again. Besides, MSGF can achieve profile control after the foaming through secondary gelation. This study could provide a constructive guide for the fractured-vuggy carbonate reservoir to improve production performance.
How Much is Steam Worth?
Authors: Aseeri Ahmed S. 
Published: November 2017

Abstract
This paper introduces how to accurately calculate steam cost through Combined Heat & Power (CHP) systems modeling. The major consumption of energy in industry takes place in the form of heat and power for the process plant(s). Optimizing the CHP system can lead to immense savings in the energy consumption of the plants thereby largely reducing the operating costs.
This paper provides a step-by-step construction of a CHP model and illustrates the fluctuation of steam production cost as each component of the CHP system is added or the operating mode is changed. In addition, it will highlight how to use the opportunity value of steam as an alternative to steam production cost for energy targeting purposes.
The cost of power can be easily linked to the Electricity Tariff since electricity is a common commodity. Steam cost, however, cannot be directly linked to any common commodity (including Fuel) and has to be calculated independently for each application to account for all operating factors and limitations that may impact steam production cost. Steam can be produced directly from burning fuel in boilers, making its cost very high. It also can be produced as a byproduct form waste heat recovery which makes its cost minimum. Most industrial applications will have a combination of boilers and waste heat recovery systems which makes steam cost calculation very hard without robust modeling. The inclusion of power recovery in the steam system through steam turbines will make the calculations of steam cost even more complex and varying with almost every operating mode.
This analysis is applicable to both existing plants and new projects. In existing plants, this analysis will help as a KPI for energy monitoring and an accurate measure to calculate the actual production cost in each process area as well as pinpoint areas of potential improvement. On the other hand, for new project it will help to properly size energy-efficient utilities systems to match process demands with minimum operating and capital cost. It can also help in doing what-if analysis to examine different expected operating scenarios and design change considerations.
Nanomaterials-Enhanced High-Pressure Tolerance of Borate-Crosslinked Guar Gels
Authors: Alharbi Abdulrahman , Liang Feng , Al-Muntasheri Ghaithan A. , Li Leiming 
Published: November 2017

Abstract
Borate-crosslinked guar gels are widely used for hydraulic fracturing treatment of wells at temperatures of about 100-300°F due to their advantages such as low cost, ability to reheal upon shearing and operational simplicity. These fluids, however, may lose some or even all of the gel viscosity under sufficient high pressure, especially at elevated downhole temperatures. Although this process could be reversed when the pressure and/or temperature drops, it may potentially cause adverse operational issues such as proppant screenout where the proppant cannot be placed.
Recently we found during the lab research studies that the viscosity loss of the borate-crosslinked guar fluids under high pressure could be mitigated with a number of novel nanomaterials. This paper examines three specific nanomaterials. These enhancing nanomaterials were applied to the borate-crosslinked guar gels as a liquid additive, with dosages typically at about 0.02%-0.12% by weight. In one example, the addition of 1 gpt of nanomaterial-I (0.02% active nanomaterials) enhanced the borate-guar fluid viscosity by about six times at the pressure of 8000 psi. In another example, when 2 gpt of nanomaterial-II (0.04% active nanomaterials) was added, the fluid viscosity was enhanced by about nine times under a pressure of 8000 psi. As the result, the viscosity boosted by nanomaterial-II under high pressure was more than enough for the fluid to function normally to render fractures and transport and place proppant. Other nanomaterials including nanomaterial-III also significantly reversed the high pressure-induced viscosity loss for the borate-crosslinked guar fluids.
These nanomaterials may have rendered more attractive interactions among the guar polymer chains, thus stabilizing the crosslinking of the fluids when the borate-guar bonding was reduced under elevated pressure and temperature. The detailed results of the lab tests at high pressure, as well as fluid chemistry will be discussed in this paper.
Parameters Affecting the Fractured Well Productivity: Proppant Pack vs. Pillar Fracture - Numerical Study
Authors: Gomaa Ahmed M. , San-Roman-Alerigi Damian P. , Alnoaimi Khalid R. , Moraes Alvaro J. 
Published: November 2017

Abstract
Gel damage, fines migration, multiphase flow, and non-Darcy flow are the primary effects that reduce the conductivity of the conventional proppant pack. Therefore, a recent technology was introduced to mitigate those impacts by substituting the porous proppant pack in the fracture with propped pillars surrounded by a network of open channels. In this technique, the fracture is held open by discrete conglomerations of propping materials, known as proppant pillars. Consequently, the flow capacity of the open channel is several orders of magnitude higher than that of a proppant pack. Another advantage of this method is the reduced proppant mass because more area is left open for flow. Most of the available literature investigates the formation of proppant pillars the stability at subsurface conditions. This study aims to characterize the impact of the technology in hydrocarbon production and identify key optimization parameters.
Therefore, a 3D numerical model was constructed to simulate the hydrocarbon flow from the reservoir through the fracture towards the wellbore, Gomaa et al. 2017. The model is used to investigate the relation between the fracture well productivity and different fracture and reservoir properties: reservoir effective permeability, vertical to horizontal permeability ratio, reservoir drawdown pressure, proppant conductivity in the near wellbore region, proppant conductivity in the far-field region, the radius of last proppant stage, and channel width.
The results showed that for conventional proppant pack a CFD value of 30 maximizes the Jd value; this agrees with the previous findings by Cinco-Ley and Samaniego-V (1981). In the case of pillar fracture technology with highly conductive channels, the numerical model showed a significant improvement in well productivity, even when the proppant conductivity was low. In the case of high proppant conductivity and high CFD values, the maximum increase in well productivity index was approximately 25%; however, for low CFD values, the channel fracture had a significant impact on productivity, improving it up to 120%.
Statistical analysis of the results evinced that the proppant conductivity in the near wellbore region had a major effect on the well productivity; whereas proppant conductivity in the far-field had little impact. The analysis also revealed that for every reservoir type, there are different combinations of CFD and proppant conductivity that maximize Jd, even if CFD &lt; 0.1. These results suggest that there is a relationship between the dimensionless fracture conductivity and the near-to-far-field permeability ratio, which has a significant influence on the results.
Simultaneous Low-Frequency Data Acquisition Using Amplitude Modulated Half-Cycle Pseudorandom Sweep
Authors: Nakamura Y. , Takanashi M. , Kunishi Y. , Sakakibara J. 
Published: November 2017

Abstract
Simultaneous acquisition is increasingly required for efficient operation of recent high-density and high-S/N seismic. Low frequency signals plays an essential role in recent imaging technologies such as full waveform inversion. Here, we developed new sweeps designed to simultaneously acquire low-frequency multi-shot data. Unlike other methods, our technique completely decomposes simultaneously acquired data, and therefore can efficiently obtainhigh-quality shot data.
The complete decomposition is achieved by amplitude modulation for repeated sweep sources. The signal for repeated sweeps exists at discrete frequencies compared with higher frequency resolution determined by the total time. Amplitude-modulated sweeps can be completely differentiated from the original sweep because modulated signals are assigned at empty frequency components. With the use of amplitude-controllable sources, our simultaneous method is available without changing the acquisition system and sampling rate. Besides, side-lobe free, low-frequency source can be obtained by so-called Wischmeyer-type half-cycle pseudorandom sweeps. The combination of half-cycle pseudorandom sweeps and amplitude modulation achieved simultaneous acquisition of low-frequency, high-quality data.
We acquired field crosswell seismic data using piezoelectric sources and hydrophones. The depths of the source and receiver wells are 50 m and the well distance is 64 m. We excited six amplitude-modulated pseudorandom sweeps at the same time, and each hydrophone receives mixed signals. The results showed that the shot gather obtained by simultaneous acquisition is equivalent to the gather obtained by single source. Amplitude modulated sweeps successfully produces each shot record without any cross talk. It is also confirmed that pseudorandom sweeps provide broad band data without side–lobe desirable for full waveform inversion
Our approach should contribute to reductions of acquisition time and cost for borehole and shallow marine surveys. Since amplitude modulation is applicable for amplitude-variable sources with arbitrary sweep designs, our method may be applied for broadband vibrotor acquisitions.
Boost Capacity of Velocity String Completions in Sultanate of Oman by Including Sliding Side Door
Authors: Hinai Khalid , Veeken Kees , Janusz Norbert , Mabsali Laila , Naabi Hajer , Al-Ruheili Sharifa , Ruzaiqi Musallam 
Published: November 2017

Abstract
Velocity strings are routinely installed to remediate liquid loading of gas wells. However, besides restoring stable production, velocity strings also reduce well capacity, easily by up to 50%. In PDO, a sliding side door (SSD) was introduced as part of the velocity string completion to reduce the loss of capacity by facilitating additional gas flow via the new annulus created between velocity string and original tubing. This paper documents different field cases that demonstrate how the SSD is manipulated to maximize well capacity, which in some cases was doubled for more than 1 year. The paper also presents modelling of gas production via velocity string, annulus or both (concurrent). Commercial software was not able to accurately predict the instability of concurrent gas production.
Innovative Use of Drones Improves Safety on Asset Integrity
Authors: Kumar V. Sivaraj 
Published: November 2017

Abstract

Objective/Scope
The objective is to find a safer and efficient method for carrying out inspection on the jack up legs and inside tanks supporting ADNOC and NDC pillars.

Method/Procedures
Offshore rigs require to be surveyed every year with the intensity of examination increasing between annual, intermediate and five-yearly frequencies. Examination includes numerous challenging compartments and spaces. These could be: Seawater tanks (normally closed and sealed), rig legs (hundred or more feet tall) underside of helidecks (over water). NDC introduced use of drones for tanks surveys thus mitigating all risks and introducing commercial efficiency as a lot of preparatory costs were avoided and the rig outage time considerably reduced.

Result/Conclusion
NDC decided to pioneer the region's first drone inspection of tanks and hull structures for offshore units amongst the drilling contractors thus demonstrating how the use of this technology can be applied to greatly improve safety, eliminate risks, increase efficiency and reduce costs. In a pilot trial of the concept the company demonstrated how a typical week long inspection program can be completed in a single day – a cost and efficiency improvement of almost 700%. Risks include lack of oxygen, fall from heights and injuries from obstructions. Of course experienced industry staff takes a lot of precautions before attempting such tasks. In fact companies have developed "Golden Rules" that govern activities inside confined spaces.

Novel
Scaffolding needed to be erected inside tanks using specialized crews at considerable cost. Tanks needed to be ventilated in advance of the tanks entry. Work needed to be done at heights with staff working on scaffolding with limited lighting. Rig time was being lost when it was brought to the jetty for surveys for ensuring safe access before surveys could be carried out.