bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impact of Surfactants on Fracture Fluid Recovery
Authors: Palla Chandra , Weaver Jim D. , Benoit Denise , Lu Zheng , Vera Noe 
Published: December 2014

Abstract
One of the many challenges of unconventional reservoirs is maximizing the recovery of fracturing fluid following hydraulic fracturing treatments. Effective fracturing fluid recovery reduces water saturation of the fractured network and fluid invasion into the formation, enabling better hydrocarbon production from the reservoir. Each chemical component present in complex fracturing fluid systems should first be carefully formulated to achieve the stimulation design requirements for the well and second to help ensure complete or maximum recovery of the broken fracturing fluid.
To help achieve maximum fracturing fluid recovery, it is necessary to understand the complex, multistep processes that occur during the fracturing fluid breaking chemistry (gel degradation) and to incorporate this understanding into the fracturing fluid design. Considerable attention has been given to insoluble residue, breaker concentration, break time, and broken fluid viscosity, all which are crucial for fluid recovery, but these do not address the tendency of insoluble materials contained within the fluid or formed during the polymer degradation process to aggregate, which can result in a significant loss of proppant pack permeability. Polysaccharide-based polymers are typically degraded by breakers composed of enzymes, oxidizers, or acids. These breakers are designed to reduce viscosity of the fluid to enable easy flowback, but they generally do not degrade the polymer completely to the monosaccharide state; rather they leave fairly long chained oligomers. These broken polymer fragments tend to aggregate, forming malleable flocs. The nature of these oligomeric fragment aggregates, such as type, size, and strength of the association, affect the efficiency of fluid debris recovery following a fracture stimulation treatment.
Surfactants added to the fracturing fluids, if properly chosen, can also act as inhibitors to the formation of the oligomeric aggregates and prevent flocculation, thus helping to avoid a significant loss of proppant bed permeability. This paper demonstrates the importance of surfactants in preventing permeability damage resulting from oligomeric polysaccharide aggregation. Selection of the proper surfactant helps prevent flocculation and enhances the recovery of broken fluids from proppant packs.
Fracture design engineers can use these strategies to maximize both the rate and efficiency of fracturing fluid recovery following the fracture stimulation of a well. This can lead to improved hydrocarbon recovery and is particularly important for the stimulation of extremely low permeability, unconventional reservoirs.
Interaction between Multiple Injections Using Tightly Coupled Fluid-Structure Interaction Computational Algorithm
Authors: Bai Jie , Lin Avi 
Published: December 2014

Abstract
Recent technologies developed for drilling, completion, and fracturing in horizontal wells have allowed the oil and gas industry to effectively use multistage fracturing stimulation treatments to help improve production in tight and unconventional gas and oil reservoirs. The fracturing process usually involves placing multiple perforation clusters exposed to the injected fluid in each treatment's stage. It has been shown that very strong interactions occur between the fractures propagating from the clusters, which further influence the effectiveness of production following a fracturing treatment. This paper presents a computational methodology to simulate and analyze the major physics associated with the interactions between multiple injections using a tightly coupled fluid-structure interaction (FSI) numerical model for hydraulic fracturing. This approach uses the finite element method (FEM) to computationally evaluate the stresses and deformation of elastic rock blocks. Nonpenetration contact conditions between adjacent solids, coupled with tensile and shear failure models, are developed to describe fracture evolution and its interaction with the rock blocks. The fluid flow in opened fractures is modeled using the cubic law formulation. The proposed coupling computational method leads to an integrative algebraic system for a set of variables that fully describes this multiphysics phenomenon, including rock block corner displacements and Lagrange multipliers for cases where the blocks are in contact, along with the fluid's pressure at junctions of the opened fracture network. The suggested algorithm solves all of the unknowns simultaneously and in a tightly coupled manner. This algorithm is not limited to the specific study of the interactions between hydraulically induced fractures from different perforation clusters, but it can also be used to properly describe the interactions between hydraulically induced fractures and natural fractures. Yet, because of the existence of natural fractures, the interactions between multiple injections become more complicated than the interactions between only hydraulically induced fractures. In these cases, the natural fractures between multiple injections provide a stronger interaction and pathways for injected fracturing fluid between multiple injections. The spacing of injection clusters is studied for its effect on fracture length and the width of fractures for each injection cluster.
Topside Installation by Float over – Engineering Challenges
Authors: Cherian Litty Dani , Suresh P. K. , Takieddine Oussama Halim 
Published: December 2014

Abstract
In recent years there has been a significant rise in heavy integrated Topsides for the new offshore fields in the Arabian Gulf. The Topside designs are increasingly becoming more complex and heavy. Installation of these decks through float over philosophy is the most sought after method. With its proven efficiency and cost effectiveness in installing those heavy topsides, this method has become well known in the Arabian Gulf. The significant savings in time and cost of offshore hook up and commissioning and the relatively reduced risks offshore makes it the preferred option in comparison to modularized lifting of the topside.
Float over is an operation of mating of a topside structure, carried on a cargo barge, to a fixed (jacket) substructure. Normally the layout of the jacket and topside are designed such that it will be suited for a specific barge size in mind. The selection of barge size (dimension) corresponds to the target weight of topside and center of gravity location. Although the method appears simple, it requires meticulous planning from very early stages of the FEED design. Float over installations are comparatively weather sensitive and responses (motion behavior) of the float-over barge, carrying the topside, in waves are crucial and must be determined. The impact loads due to barge motions during mating are extremely important for jacket and topside design.
The involvement of experienced Naval Architects from the FEED stage of design to carry out all installation studies leading up to float over is an absolute necessity to ensure good platform design. Awareness of potential challenges during float over design and installation shall help in the design of the platform and thereby avoid surprises later.
This paper presents the float over philosophy, method of performance, systems used, technical aspects and various parameters to be considered during engineering for float over installation in the Arabian Gulf from a Naval Architect's perspective. This includes discussion on the importance of weight control of topsides, selection of barge for float over installation, finalization of support heights for topsides on barge, typical float over installation aids etc. The paper also discusses the typical technical analyses required to be performed for the design. The discussion in this paper is limited to float over installations using conventional load transfer method (by ballasting) and using normal spread mooring arrangement.
An Operator Feedback on the Installation of a Pipeline Intrusion Detection System
Authors: Audouin Grégoire , Rupert Serge , Popineau Dominique , Minto Chris 
Published: December 2014

Abstract
"Third Party Interference", whether intentional or accidental, is responsible for more than half of the pipeline failures in the world. The consequences can be catastrophic for people, the environment but also for facilities availability. The project presented here considers the use of a communication optical cable, laid with the pipeline, in order to detect intrusions and also leaks. Field data from an operational test was acquired at the Balhaf LNG facility in Yemen in December 2012.
The LNG plant operations had been subject to numerous sabotage actions, impacting the pipeline feeding gas to the plant, and therefore the plant availability. A security review concluded that there was a need to implement specific security measures to allow early detection of potential threats. The requirement was to minimize new equipment installation in the field, so as to avoid personnel exposure, by making use of the already installed communication optic fiber communication cable.
A fiber optic based detection system was selected. Such systems detect acoustic signals via the optical pulses sent within an optical fiber, known as Rayleigh scattering. For example repeated and regular impacts on soil will trigger an "excavation" alert and a security team can be sent to stop intruders before they reach the pipeline. The advantage of this technology is that it makes use of one of the optical fibers within the communication cable, already installed in the pipeline trench. There is no need to install additional new cables alongside the pipeline.
Since its resulting installation, the system has demonstrated that this technology can reliably contribute to pipeline security by enabling operators to detect and listen to pipeline external threats. Fiber optics can also be used for leak detection. Such detection is based on the continuous measurement of the temperature gradient between the fluid transported and the surrounding ground, the environmental effects on the ground of the escaping product or the multiple acoustic signatures of a leak. This functionality is being tested and evaluated. This technology has the potential to drastically improve operational safety and security for pipelines deployed within challenging environments.
Ageing Offshore Well Structural Integrity Modelling, Assessment and Rehabilitation
Authors: Ramasamy Ramesh , Aljaberi Manea , Aljunaibi Hamad 
Published: December 2014

Abstract
Zakum Development Company (ZADCO) is operating Upper Zakum (UZ) Field offshore Abu Dhabi consisting several offshore wellhead platform towers (WHPT) which have been in service for over 30 years and evidence of severe corrosion has been found on majority of these well's conductors and casings.
A major challenge faced by ZADCO is to repair corroded well's conductor casing to prevent well structural collapse and extend the life further to allow for safe and planned retirement. The challenges faced during the assessment includes the absence of design basis, well age, data accuracy and drilling quality for 30 years, the challenges takes another dimension when factoring the number of wells and possible different configurations. They way forward was to categorise the wells into several groups with close design configurations and then reverse engineer the design basis to a build a structural model for that fits the various wells configuration to establish the minimum thicknesses to assure well's structural integrity, and the requirement for life extension by suitable repair method.
This paper outlines the activities undertaken to design and implement an effective process for evaluating the structural integrity of aging well conductors considering over 6000 possible well configuration scenarios. The paper describes the engineering methodology involved in the integrity assessments for well conductor evaluation using analytical methods to assess the present strength and stability states of the conductor/casing assembly based on corrosion inspection data and the knowledge of existing cement elevations and operating conditions of the well. Operability guideline plots are generated to present the available safety margin of the aging conductor/casing system, and to enable well conductors with unacceptable structural integrity to be identified. Where safety margins are poor, repair solutions and mitigation methods are also developed for implementation on the affected conductors and casings.
A detailed rehabilitation flow-chart is also developed to assist engineers in the repair/replace decision-making process, with comprehensive guidelines for assessing and executing the rehabilitation steps for extended safe operations of ageing conductors, hence prolonging the well operating life.
Customizable Synergistic Dual Breaker Technology Improves Fracture Fluid Cleanup
Authors: Cortez Janette , Singh Dipti 
Published: December 2014

Abstract
Natural and synthetic polymers are commonly used within the oil and gas industry as viscosifying agents in hydraulic fracturing applications. Hydraulic fracturing involves pumping of a highly crosslinked fluid into a formation to create fractures. The viscoelastic fluids are used to provide sufficient viscosity for proppant suspension, transport, and enhanced fracture width. Breaking the crosslinked polymers after the fracturing operation is a crucial step that can greatly impact hydrocarbon production. Conventional breakers, such as oxidizers, are most commonly used for breaking fracturing fluids; however, these breaker packages sometimes show inferior regained permeability at lower temperatures (100 to 160°F). Regained permeability studies with fracturing fluid compositions tested in low-perm cores show that persulfate-type oxidizing breakers do not always adequately degrade the polymer; furthermore, higher concentrations do not always show improved breaking. This paper presents an alternative breaker solution that is superior to conventional breakers in terms of improving regained permeability.
Recently it was shown that in situ acid-generating hydrolytically degradable polymers, in combination with oxidizing breakers, dramatically improved the regained conductivity of the proppant pack without the detrimental effects associated with the use of higher breaker concentrations at lower temperatures. For example, test results show that, even at temperatures as low as 150°F, the synergistic phenomenon of this dual breaker system provided multiple and beneficial functions. The hydrolysis rate of degradable polymers to generate acid in situ is dependent on several factors. The wide variety of degradable polymers containing ester-linkages that are available permits one to select a polymer that will result in a desired break profile for the given conditions, making this chemistry customizable.
In addition, these acid-generating self-degradable polymers are biodegradable, potentially minimizing health, safety, and environmental (HSE) concerns.
Conductivity improvement as compared to using a breaker system based on individual components are attributed to the improved cleanup provided by the synergy between the degradable polymer and the oxidizing breaker (even at lower temperatures). This represents a significant improvement to current technology.
Effect of Sequence Stratigraphy-based Facies Modeling for Better Reservoir Characterization: A Case Study from Powder River Basin
Authors: Odezulu Christopher , Olawole Seun , Saikia Kalyan , Mento Dean 
Published: December 2014

Abstract
The integration of high quality sequence stratigraphic analysis plays an important role in the 3D modeling of reservoir facies and petrophysical properties. It provides a better characterization of complex geology and helps to reveal hidden pays that may not have been found with conventional techniques. This paper demonstrates the benefits of effective sequence stratigraphic interpretation in creating a holistic 3D reservoir model and in identifying probable hydrocarbon traps in the study area.
The paper establishes a sequence stratigraphic framework, consisting of two lowstand system tracts (LSTs), one highstand system tract (HST), and one transgressive system tract (TST), using integrated interpretation of well logs and seismic data. Studies of the depositional pattern of the framework revealed three main sedimentary facies (marine, flood plain, and fluvial) with complex lateral and vertical relationships. In conventional approaches, a global facies average calculation is assumed, creating an unrealistic model with a stationary condition. In this study, layer-wise facies trend maps were generated, using lithotype proportion map (LPM) and vertical proportion curves (VPC), to capture the geological inhomogeneity. While making the model geologically more realistic and non-stationary, facies boundaries from the sequence framework are honored by constraining the final 3D facies simulation through customized lithotype rules. Next, a petrophysical property modeling technique is used to populate individual litho-groups for porosity, saturation, and total organic carbon (TOC) by interval and constrained by facies. This process leads to a holistic, geology-controlled 3D reservoir model that reveals hidden pockets of LSTs with high porosity values in the reservoir, which provide promising exploration sites for future development. This study also shows that the TST has an abundance of high value TOC; consequently, it is more likely to be genetically related to the source sediments. In conclusion, the integration of sequence analysis played a significant role in the development of a realistic 3D distribution of reservoir facies, providing a better prediction of reservoir properties, increasing recovery, and reducing uncertainties in field development.
Technology Test Site: Value Proposition for a "Live Field Laboratory"
Authors: Sanni Modiu L. , Allen John T. , Jennings Scott S. , Jervis Michael A. , Ayadiuno Chris B. , Ali Razally M. , Najrani Husain N. 
Published: December 2014

Abstract
In order to accelerate the development, early uptake and deployment of new technologies being developed in-house by Saudi Aramco's EXPEC Advanced Research Center (EXPEC-ARC), and technologies being developed in collaboration with industry service providers and academia, Saudi Aramco started the development of a Technology Test Site (TTS) in a producing oil field environment. The TTS, when completed, will be a ‘live field lab’ where many emerging new technologies and innovative ideas can be tested and tried under normal reservoir conditions.
To date, six wells have been drilled and completed. Extensive and comprehensive geoscience and engineering data were acquired for detailed reservoir characterization and description; including over 11,000 ft. of core data. The preliminary results from the on-going elaborate data analyses, including dual energy CT (X-ray computed tomography) scan, geomechanical data, and log data yield some intriguing insights into the often ignored non-hydrocarbon bearing Upper Cretaceous and Tertiary formations. The on-going data analyses showed why certain intervals are incompetent to withstand mud weight of 8.33 ppg (fresh water equivalent) while drilling. Attempts are being made to extract requisite information that may help to resolve some of the challenges (e.g. loss circulation while drilling and "near surface" seismic anomalies) frequently encountered across the Tertiary and Cretaceous shallow formations.
This paper highlights the value proposition for a ‘live field lab’ technology test site, lessons learned during the first phase of the TTS development, some results of on-going analysis, and some of the best practices that were developed.
Rock-typing In Carbonates: A Critical Review Of Clustering Methods
Authors: Rebelle Michel , Lalanne Bruno 
Published: December 2014

Abstract
Carbonate reservoir Rock-Types are generally complex to identify due to the intricate impact of diagenesis on the porous network. Based on a many years of experience working with carbonates, TOTAL has developed over time a dedicated Rock-Typing workflow contingent on the integration of all core and log data at all possible scales (from SEM to field). The result is designated as SRT standing for Static Rock-Types.
Considering that the key point of Rock-Typing is to capture as straightforward as possible a relationship between geology and petrophysics, SRT could be considered as a geologically and petrophysically homogeneous group of rocks with specific distributions and relationships between K, Φ and Sw, reflecting the main petrophysical properties. The petrophysical distributions within each Rock-Type must be stationary or homogeneous within petrophysical domain and follow certain geostatistical behaviors. Moreover, there must be a specific and comprehensible link with the geology (lithology, stratigraphy, sedimentology and diagenesis) in order the petrophysics to be extrapolated in 3D.
This paper presents a critical review of the most common clustering methods (Lucia, Pittman, RQI, FZI …). Some are geologically driven, others petrophysically driven, some are defined at plug or even core scale, others at log scale. After comparing the pros and cons of each method, the SRT approach reconciles plug to log scale on one side and geology (including diagenesis) and petrophysics on the other side.
The discriminating parameters for SRT building have to be found among CCA (Φ, K, ρ), SCAL (Pc, PTR), accurate thin sections description (texture, porosity types, cement types, crystals size), and logs responses (core logs, well logs including imagery and NMR).
SRT can consequently be propagated in non-cored intervals through electro-SRT models based on the sedimento-diagenetical model provided by the sedimentologists allowing the 3D distribution of petrophysical properties between the wells.