bluuebunny/crossref_metadata_2025_split huggingface dataset:
Numerical Simulation of Natural Gas Flow in Anisotropic Shale Reservoirs
Authors: Negara Ardiansyah , Salama Amgad , Sun Shuyu , Elgassier Mokhtar , Wu Yu-Shu 
Published: November 2015

Abstract
Shale gas resources have received great attention in the last decade due to the decline of the conventional gas resources. Unlike conventional gas reservoirs, the gas flow in shale formations involves complex processes with many mechanisms such as Knudsen diffusion, slip flow (Klinkenberg effect), gas adsorption and desorption, strong rock-fluid interaction, etc. Shale formations are characterized by the tiny porosity and extremely low-permeability such that the Darcy equation may no longer be valid. Therefore, the Darcy equation needs to be revised through the permeability factor by introducing the apparent permeability. With respect to the rock formations, several studies have shown the existence of anisotropy in shale reservoirs, which is an essential feature that has been established as a consequence of the different geological processes over long period of time. Anisotropy of hydraulic properties of subsurface rock formations plays a significant role in dictating the direction of fluid flow. The direction of fluid flow is not only dependent on the direction of pressure gradient, but it also depends on the principal directions of anisotropy. Therefore, it is very important to take into consideration anisotropy when modeling gas flow in shale reservoirs. In this work, the gas flow mechanisms as mentioned earlier together with anisotropy are incorporated into the dual-porosity dual-permeability model through the full-tensor apparent permeability. We employ the multipoint flux approximation (MPFA) method to handle the full-tensor apparent permeability. We combine MPFA method with the experimenting pressure field approach, i.e., a newly developed technique that enables us to solve the global problem by breaking it into a multitude of local problems. This approach generates a set of predefined pressure fields in the solution domain in such a way that the undetermined coefficients are calculated from these pressure fields. In other words, the matrix of coefficients is constructed automatically within the solver. We ran a numerical model with different scenarios of anisotropy orientations and compared the results with the isotropic model in order to show the differences between them. We investigated the effect of anisotropy in both the matrix and fracture systems. The numerical results show anisotropy plays a crucial role in dictating the pressure fields as well as the gas flow streamlines. Furthermore, the numerical results clearly show the effects of anisotropy on the production rate and cumulative production. Incorporating anisotropy together with gas flow mechanisms in shale formations into the reservoir model is essential particularly for predicting maximum gas production from shale reservoirs.
Operation Readiness Plan Management Process for Successful EPC Project Execution and Start Up
Authors: Das Anil Kumar , Al Naqbi Sulaiman , Kumar Ravi , Walid Mohammed , Bhasker Bhasker , Khan Aqrar 
Published: November 2015

Abstract (Category: Projects Engineering and Management: SESSION 40: Commissioning, Start-Up and Handover Challenges)

Challenges during transition of Project to Operations
➢ Timely availability of spares (Commissioning, Insurance and Operating). ➢ Updating of existing operating Manual and procedures (Brownfield) and new Operating Manuals and procedures (Greenfield). ➢ Manpower availability/required training for operation & maintenance of new facilities. ➢ Asset registration/Maintenance Plans to be completed /finalized. ➢ Maintenance contracts for equipment to be in place. ➢ Assurance for fulfilment of all Integrity requirements.
High Grade Steel Pipeline for Long Distance Natural Gas Projects
Authors: Cheldi Tiziana , Castano Michele , Spinelli Carlo Maria 
Published: November 2015

Abstract
Natural gas will play the role, in the years to come, of the main fossil fuel, even the energetic scenario is moving to the renewable sources as an alternative for the far future; natural gas will act as a "bridge" to guarantee the transition to the "green energy" from the actual one [0].
As a matter of fact the era of easy gas is "terminated", now there is the need of large investments to connect big gas reservoirs located in far and sometimes stranded locations. To have access to these reservoirs, from the logistic and economical point of view of the exploitation, the cost for gathering natural gas has to be reduced dramatically. The cost cut has to affect not only the construction but also the operational duties. So any new solution has to be properly checked, before to be put in place, to assure it must be as reliable as the actual currently used. From the mid of the 90' it has been shown as the adoption of very high pressure for the transportation of large amount of natural gas it's the easiest solution to be used; the main reason of that it's because it's based on the enhancement of current technologies used for the manufacturing of the material, for the construction and maintenance of the gas pipeline; it doesn't need any break through leap that may create a divide with the actual way or working.
The material proposed is C steel with higher strength in term of yield and tensile stress. Material as carbon steel above API 5L X80 and X90 and in some cases also X100 have been considered for this application. The paper is aimed to highlight the topic need to better understand the use of API 5L X80 C steel for pipeline (UOE & Spiral welded) to be used for mild/harsh scenarios in onshore pipeline laying.
Eni committed its interest on pipeline high strength steels by combining experimental researches and theoretic studies on structural integrity & reliability [0].
The scope is to address the design phase towards quantitative safety targets for which the reliability level specified by designer and desired by operator is pursued. X80 pipeline steel had so far not been used mainly because the lower steels grade were suitable for any of the previous applications, and also because of the predominant attitude in O&G sector to adopt new solutions is conservative; furthermore the lack of experience on "in field application", it's another reason to "freeze" the evolution process.
This project was aimed to fill these gaps through an integrated "full scale and realistic long term tests" approach. The innovation embedded in this R&D project is to have an overall cycle approach, involving the analysis of aspect related to the engineering phase, enhancement in the construction methods, and last but not the least also the maintenance and daily operational duties.
Sulfur Recovery Unit - Integrity Operating Window & the Main Issues
Authors: Adamou Adib Soufiane 
Published: November 2015

Abstract
ADGAS operates three Sulfur Recovery Units (SRUs), commonly referred to as sulfur plants, for several years, which, various issues related to the integrity impacted the operational reliability of these units. In an effort to reduce emissions and comply with environmental requirements, ADGAS has developed new modules to do Super Claus.
This paper presents the Integrity Operating Window for these (SRUs). It identifies and discusses the corrosion mechanisms and fouling that may occur in SRUs in the main section in the sulfur plants, and discusses methods of prevention, including guidelines for start-up and shutdown of equipment.
A general discussion of materials selection for SRUs is also presented. Key process parameters are identified which should be routinely monitored and controlled within designated limits. These key process parameters and their respective limits should serve to define the appropriate operating window for control of corrosion and fouling in SRU and as a basis for management of change considerations.
A specific case studies, related to Sulfur Recovery Units past operating experience is also included. Mainly, ADGAS faced many integrity issues related to the Waste Heat Boiler, Main Combustion Chamber refractory, sulfur accumulation, weld joints sulfur contamination and sulfur solidification in the sulfur tank safety devices.
Different recommendations will be addressed in order to avoid SRU unplanned shutdown based on ADGAS experience with operation the three SRUs.
Palaeogeographic Reconstruction of a Tide-Dominated Oolite Shoal Complex in the Lower Arab Formation, Onshore UAE
Authors: Lawrence David A. , Hollis Cathy , Green David , de Perière Matthieu Deville , Al Darmaki Fatima , Bouzida Yasmina 
Published: November 2015

Abstract
The Late Jurassic Arab Formation is being developed in a major gas accumulation located onshore southern UAE. The lower Arab Formation consists of wackestones to mudstones of mid ramp to basinal setting overlain by foreshoal and oolitic grainstone shoal deposits. Despite the number of well penetrations, several published models have been proposed for the palaeogeographic evolution of the shoal complex.
The grainstone-dominated interval comprises skeletal and ooid-rich wackestones and packstones grading upwards into oolitic grainstones interpreted as the result of progradation of foreshoal to ooid shoal environments. A key element to understanding reservoir architecture has been the integration of core descriptions with borehole image logs, permitting recognition and re-orientation of the main bounding surfaces and cross-bedding sets. Existing depositional models for grainstone shoals are highly schematic and not useful for defining reservoir architecture.
Two key surfaces constrain correlation and reservoir architecture: a basal hardground typified by dolomitised burrows and an upper erosion surface which terminates grainstone deposition. Shoal initiation was in the southwest of the study area with progradation of bioturbated foreshoal deposits with isolated planar cross-sets. Tidal reversals become more frequent upwards, with deposition mainly in offshore flood-oriented ooid sand ridges.
The main part of the grainstone interval is dominated by a stacked parabolic sand shoal complex comprising cross-bedded oolitic and skeletal grainstones. Initial primary macroporosity in this facies association is pervasively occluded by calcite cements. Behind the shoal complex, planar laminated oolitic grainstones accumulated in flood-tidal deltas in a broad lagoon. Progressive infilling of the lagoon by sediment supplied from the shoal resulted in basinward (northeasterly) shifting of the shoreline and development of linear beach ridges. Bioturbated to massive grainstones capping shoal complexes are clean and only patchily cemented retaining a well-connected primary macropore network.
Geometries, scales of cyclicity and facies distributions indicate analogs to modern tidally-influenced ooid ridges and parabolic bars of the Bahamian system.
Chemical Solutions to Handle Viscosified Back Produced Water in Case of Polymer Flooding
Authors: Rambeau Odile , Alves Marie-Hélène , Loriau Matthieu , Molinier Valérie , Passade-Boupat Nicolas , Lebas Geneviève 
Published: November 2015

Abstract
Polymer flooding is used as a secondary or tertiary recovery mechanism to enhance oil production and increase oil reserves. In such situations, part of the injected polymer will be back produced at the topsides at different ratios depending on the injection mode and along field life. The side effects of polymer flooding on the topsides process chain are identified as manageable trouble regarding oil/water separation, and major issues at the water treatment stage.
The presence of polymer in the produced water increases the viscosity and the severity of the emulsion. Literature dealing with viscosified water has already highlighted decreases of efficiency of water treatment technologies such as hydrocyclones, flotation, generating inadequate water quality for produced water reinjection (PWRI). A common way to optimize flotation on field is to inject additives. But the polymer impedes the action of conventional chemicals used in O&G Production.
Chemicals usually help to improve the water quality, regarding constraints of PWRI. This paper focuses on chemical approach along the separation and water treatment chain in case of back produced polymer.
For this study, we used HPAM, a high molecular weight polyacrylamide commonly used in EOR. Previous works on conventional water treatment additives have shown a high consumption of chemical to clarify viscosified water, which is not economically practicable.
Therefore, we proposed to explore another approach, first taking care of water quality upstream at the separation stage, then pursuing on chemical optimization at the water treatment stage.
At first, a lab methodology for separation studies was developed to generate a thin emulsion with controlled degradation of the polymer, simulating the characteristics of the back produced viscosified water on field. A screening of demulsifiers was carried out on emulsion containing 10% oil and synthetic polymer back produced water (up to 500 ppm HPAM). These tests have shown that water quality can be improved at the separation stage, at conventional dosage at lab scale. The remaining oil in water for 10% initial oil, depending on the residence time, is maintained in the range of few tens to few hundreds ppm. Water treatment optimization reference case was then based on few hundreds ppm of remaining oil.
For water treatment studies, oil in water emulsions were prepared by mixing oil with synthetic or real viscosified water (up to 500 ppm HPAM) with an ultra-turrax homogenizer. Different types of clarifiers ranging from 50 to 100 ppm were evaluated. These tests have shown that water quality can be improved using a combination of adequate additives. These bench lab results were confirmed on a lab conventional technology, and could be further evaluated in field trials for an integrated solution.
Drill Pipe Grades Improvements and Industry Standards Evolutions to Address Increasing H2S Challenges: a Decade in Review
Authors: Flores Vincent 
Published: November 2015

Abstract
Hydrogen Sulfide (H2S) can interact with steel tubular, and through the unfavorable combination of different factors can initiate a crack in the material, which could propagate until failure. This phenomenon can occur when stresses are largely below the material yield strength. The combination of tubular failures due to Sulfide Stress Cracking (SSC) and the rising HSE concerns when dealing with sour gas has led the industry to develop new drill pipe grades with enhanced resistance to SSC.
Material selection for drill pipe in a sour environment is significantly unclear, mainly due to the absence of existing international standard specifically related to H2S resistant drill pipe. Nonetheless, Canada has led the way by publishing their "Industry Recommended Practices" (IRP) Volume 1 in 2004; the standard was created to insist on people safety, and provide specification and guidelines to manufacturers on material properties, quality control, testing and inspection of drilling products intended to be used in critical sour wells.
Sour Service Drill Pipe as defined in the IRP has been used for over a decade in Canada, as well as in other parts of the world. Manufacturers have also developed a variety of other proprietary Sour Service grades of drill pipe and BHA. This paper proposes a review of different field cases in the Middle East and Asia, as well as an outlook of the different practices for material selection and qualification guidelines which have emerged since the past 10 years.
With the current increasing demand of domestic gas in different part of the world, some highly sour oil and gas reservoirs are being explored with H2S contents beyond what could have been imagined a decade ago. To explore, appraise and eventually develop such fields, most of the time combined with complex well profiles or deeper reservoirs, significant technical challenges need to be addressed regarding drill pipe integrity and operations safety. This paper proposes a non-exhaustive review of the newest emerging industry trends as far as international standard guidance, regional normative initiatives, and new steel developments.
Gas Injection EOR Screening by Laboratory Experiment and Sector Modeling in Carbonate Reservoir
Authors: Kumar Jitendra , Yammahi Fatmah S. , Nakashima Toshinori 
Published: November 2015

Abstract
Hydrocarbon gas injection projects are undertaken in order to maintain reservoir pressure, produce oil through swelling and reduce residual oil saturation by decreasing the interfacial tension (IFT). Along with local displacement efficiency, macroscopic sweep efficiency plays a dominant role in the success of gas injection projects, as recovery from the field depends strongly on reservoir geology and petrophysical properties.
In this paper, a procedure to screen the best injectant for implementation of a successful gas injection pilot project is discussed. To determine the microscopic sweep efficiency, PVT experiments and coreflood tests are conducted. First, minimum miscibility pressure (MMP), oil solubility and IFT values are measured through PVT experiments, which is followed by unsteady-state coreflood experiments on 200 cm long cores to evaluate the sweep efficiency at miscible and immiscible conditions. Data from the experiments are used to evaluate oil recovery in a sector model extracted from the full field model. The sector model analysis for different injection scenarios provides sweep efficiency and guidelines for the implementation of the gas injection pilot project.
The coreflood experiments show improvement in recovery in immiscible conditions due to oil swelling and reduction in IFT, while higher recovery is achieved in miscible conditions due to multiple-contact miscibility. Evaluation of the macroscopic sweep efficiency in the sector model highlights the issue of gas override, and suggests improving the sweep by gas enrichment, as well as water-alternating-gas injection (WAG).
The Successful Implementation of a "Center Of Excellence" for the Upstream Oil Sector in Kuwait
Authors: Al-Zeabot Nadia , Thomas Cyril 
Published: November 2015

Abstract
Kuwait Petroleum Corporation (KPC) directed its Upstream subsidiaries to collaboratively work towards an integrated 2030 strategy. One of the key elements to achieving the 2030 strategic objectives was to collaborate and share expertise to resolve technical challenges currently facing the upstream entities. As a result, the Center of Excellence (CoE) was successfully implemented to leverage the diverse expertise of technical talent across the three upstream entities of Kuwait Oil Company (KOC), Kuwait Gulf Oil Company (KGOC) and Kuwait Foreign Petroleum Exploration Company (KUFPEC). CoE Discipline teams comprising of experts in strategically important technical disciplines created significant business value through sharing of knowledge, lessons learned, and experiences, around specific technical challenges.
To embed the CoE as a way of working, change management was identified as a key enabler. Various interventions including organization-wide communications, focus on value creation, incentives, and capability development were implemented to build commitment and manage different stakeholder groups. Specific messages were deployed through high impact communication tools to build wider stakeholder support. The Upstream leadership provided sponsorship and visible support to drive implementation and ensure that value from CoE is recognized. This multi-pronged approach helped embed CoE within the inherent fabric of upstream entities, enabling it to deliver business value.
Wasia Unconventional Oil Exploration Potential in Western Onshore Abu Dhabi
Authors: Taher Ahmed , Al Zaabi Mohamed R. 
Published: November 2015

Abstract
The Wasia unconventional oil potential in west onshore Abu Dhabi is comprised of Mauddud, Shilaif and Tuwayil formations.
The Mauddud potentiality is a result of the downward oil migration from the mature Shilaif Kitchen. The high maturity of Lower Shilaif creates a fracture network that facilitates the primary migration downward into the Mauddud formation. This resulted in filling the Mauddud formation below the Shilaif kitchen and possibly the surrounding areas. Mauddud oil accumulation in the basin was supported by the presence of high hydrocarbon shows while drilling and high hydrocarbon saturation in the interpreted logs.
In the Shilaif source rock, there are three distinct intervals that have potential for shale oil exploration activities in Abu Dhabi. The Lower Shilaif has the highest maturity values and the highest recorded porosity with a very low permeability, while the Upper Shilaif potential represent the thickest part and is expected to have higher permeability values as a result of the presence of lower argillaceous content.
The Upper Tuwayil is comprised of shale sediments that are intercalated with Sandstone streaks. The Sandstone was developed as isolated but laterally extensive sand bodies that are separated by the shale layers. Tuwayil sandstone may represent an unconventional tight oil potential similar to that found in many other basins.
The First Successful Chemical EOR Pilot in the UAE: One Spot Pilot in High Temperature, High Salinity Carbonate Reservoir
Authors: Al-Amrie Omar , Peltier Sophie , Pearce Adrian , Abu-Dhabi Total , Al-Yafei Arafat , Morel Danielle , Bourrel Maurice , Bursaux Romain , Cordelier Philippe , Jouenne Stephane , Juilla Hugo , Klimenko Alexandra , Levitt David , Nguyen Michel 
Published: November 2015

Abstract
In 2014, Total performed a surfactant-polymer single-well pilot to test the effectiveness of a surfactant formulation developed in-house, and including a new proprietary class of surfactants with improved temperature- and salinity-tolerance characteristics. This paper unveils the results of this pilot which targeted a high temperature, high salinity carbonate reservoir. The operations were performed on an oil bearing reservoir of Lower Cretaceous age, in an offshore field operated by Total since 1974 and located 180 km offshore Abu Dhabi. Dedicated topsides were designed and installed for this EOR project. Extensive in-house laboratory studies were performed to select and synthesize the chemicals. Specific simulations, using laboratory results as input, were carried out to predict the pilot performance, design the Single Well Tracer Tests (SWTTs), and size the equipment.
In this paper we will discuss the workflow used to select the most appropriate well and present the methods and results used to characterize the reservoir. Then we will relate it to the surfactant-polymer injection field operations. Finally the reservoir monitoring activities that were necessary to preserve reservoir integrity and demonstrate the pilot efficiency will be described.
The strong decrease in remaining oil saturation measured after the chemical EOR pilot clearly proves the effectiveness of the chemicals synthesized by Total to mobilize the remaining immobile oil after water-flood.
These positive outcomes change the perception of CEOR in hot, saline Middle-East carbonate reservoirs, and could be a "game changer".