bluuebunny/crossref_metadata_2025_split huggingface dataset:
Wastewater Injection and Slip Triggering: Results from a 3d Coupled Reservoir/Rate-and-State Model
Authors: Babazadeh Mohsen , Olson Jon 
Published: October 2018

Abstract
This paper present results from a combined model that brings together injection physics, reservoir dynamics, and fault physics to better explain the primary controls on induced seismicity. We created a 3D fluid flow simulator with embedded discrete fracture technique, coupled with a 3D displacement discontinuity geomechanics model that uses rate and state friction to model stable or unstable rupture events. The model incorporates reservoir properties including vertical and horizontal extent; stratification including top-seal, reservoir, and basement; multiple permeability and porosity. Injection parameters include rate and pressure. Fault properties include size, 2D permeability, and frictional properties. Several suites of simulations were run to evaluate the relative importance of each of the factors from all three parameter groups.
We find that the injection parameters interact with the reservoir parameters in the context of the fault physics. For a given reservoir and fault properties, injection rate increases magnitude and frequency of earthquakes, and volume is unimportant. For a different reservoir, these relations may change, leading to the need to specify/examine the injection parameters only within the context of a particular faulted reservoir. Both injection and reservoir properties can interact with the fault properties to trigger or impede slip, so that the magnitudes of induced earthquakes depend on all three groups of parameters. For example, the fault permeability structure is a key factor in inducing earthquakes in basement in many reservoir scenarios. In some cases, the main component in inducing seismicity include the pressure on the fault and its rate of change, which affect how big of a fault area is being affected, and therefore initial earthquake size. By implication, selecting reservoirs for wastewater disposal may involve prioritizing those reservoirs with higher permeability as it takes longer for fluid pressure to exceed critical pressure and trigger large unstable rupture events on nearby faults.
Analysis of Horizontal Well Fracture Interactions, and Completion Steps for Reducing the Resulting Production Interference
Authors: Daneshy Ali 
Published: October 2018

Abstract
An oft-occurring outcome of modern fractured horizontal well production systems is considerable interactions between adjacent hydraulic fractures; in the same well (intra-well), or in offset wells (inter-well). An unwanted consequence of these interactions is production interference. Inter-well interactions can cause production re-routing from one well into the adjacent well, and occasionally even short-term loss of production from one of the wells. Effects of intra-well fracture interactions may include production re-distribution within the created fractures, and, patchy depletion of the reservoir surrounding the horizontal well.
Causes of intra-well interactions include stress shadowing and Dynamic Active Fracture Interactions (DAFI). Under common fracturing practices these can cause unpredictable deviations in fracture growth path which can even lead to coalescence of some fractures and non-uniform production from individual fractures. Another important outcome of these interactions is differences in created fracture lengths, with some fractures extending a long distance into the reservoir. Recent trends towards larger size treatments and shorter spacing between individual fractures are intensifying these effects.
Inter-well interactions include frac-to-frac connections that hydraulically link the two wells together; either temporary (while fracturing only), or long term with conductive links. The latter can cause immediate production interference. Another less severe type of interaction is fracture shadowing, which may cause delayed production interference.
Paper discusses how these interactions are influenced by the stress environment, formation mechanical properties, type of completion (openhole liner, cemented liner, single fractures vs. multiple fractures), fracture orientation and spacing, well spacing, and perforation schemes. It presents completion steps that reduce the uncertainty in fracture growth path and location of longer fractures. It also shows how and why combining these steps with simultaneous and zipper fracturing can reduce damage to the wellbores and the extent of production interference.
On the positive side, analysis of fracture interactions can also provide valuable information about fracture characteristics; including estimates of length, orientation and conductivity, etc. With proper preparation, the information can also be used for real-time evaluation of the created fractures and treatment modifications to reduce severity of production interference.
Managing the Drilling Function
Authors: Willis John , Jackson Richard , Swartz Harris 
Published: October 2018

Abstract
An international company with multiple drilling groups in separate business units on three continents created a global drilling function that increased organizational capabilities and minimized overhead costs. The organization has encompassed up to 13 separate drilling groups and a headquarters staff organization. The new structure, primarily involving land operations, has demonstrated success for more than 5 years.
The processes and systems described herein have some special design feature for drilling, or are unique among the functional organizations of the company. These include identification of important areas, the role of the headquarters group, drilling group structure, systems, and systems components. The processes used in the drilling function that are common to all large organizations are not covered.
Several important conclusions have been demonstrated. Standards and guidelines must provide balance between risk management, innovation, and allowance for unusual situations. Consistency of positions, responsibilities, and processes across all business units enables efficient, standardized global processes. An organized system to create communication between business units can stimulate exchange of ideas, experiences, and technology that otherwise would not be communicated, not for lack of desire, but simply due to the demands of the day-to-day business.
Technically complex systems managed globally justify greater investment and support, and deliver superior results to specialized local systems. Non-complex systems that require low-level customization for separate units may be more effective and economical when managed locally. Management of staff movements and career development across business units provides more consistent opportunities and global optimization of staff capabilities.
Given the number of large oil companies, it is safe to presume that many approaches to managing the drilling and other functions have been used. However, few approaches are published. This paper presents a comprehensive overview that can aid in the development or refinement of functional organizations.
Well Log Analysis for Reservoir Characterization of Famenian Carbonates with Criterion of Texture Heterogeneity
Authors: Minigalieva Gulnaz , Nigmatzyanova Albina , Burikova Tatyana , Privalova Olga , Akhmetzyanov Ruslan , Kinzikeeva Aigul 
Published: October 2018

Abstract
Most carbonate rocks are characterized by high heterogeneity which implies changes in their vertical and lateral distribution, geometry and properties based on special aspects of their generation, depositional history, evolution and influence of exogenic processes.
The oil-bearing carbonates of the Famenian in the study area tend to occur as complex reservoirs characterized by heterogeneous storage and flow potential. Diagenetic secondary changes resulted in various types of rocks differentiated by the configuration of the void space. The most extensive secondary changes evident to a greater or lesser degree in all the cored sections of the analyzed wells were caused by leaching which in its turn modified the carbonate fabrics and created heterogeneity. The configuration of the void space formed the foundation for the differentiation of petrophysical rock types.
The findings obtained from the detailed lithological and petrophysical description of the Famenian rocks were used to group the identified reservoirs into the following classes based on the prevailing configuration of the void space, i.e. porous, vuggy-porous and fractured-vuggy-porous[1]. While the porosity values are comparable, the fractured-vuggy-porous type has the highest flow potential (maximum permeability values of the three types) due to leaching whereas the vuggy-porous type is characterized by average permeability and the porous one has the lowest flow potential (Figure 1). The type of the void space also predetermines the shape of the capillary pressure curve and respectively the pore throat radius distribution (Figures 2 and 3) as well as electrical and acoustic properties of the rocks.
Methane Flow in Shale Nanopores with Kerogen Microstructure by Molecular Simulations
Authors: Wu Tianhao , Firoozabadi Abbas 
Published: October 2018

Abstract
We perform a systematic molecular investigation of construction of the kerogen matrix and simulation of gas flow. The kerogen matrix is constructed by 60 Type-II kerogen macromolecules. The pore space is generated by means of dummy atoms. The porosity, surface area, and transport diffusivity are analyzed. In the past, the simulations of methane flow have been performed assuming rigid molecules in the kerogen matrix. We extend the simulations from rigid molecules to flexible molecules in the kerogen matrix. The gas flow simulation is performed based on the boundary-driven method. The results show that the relaxation of the generated kerogen matrix after the deletion of dummy atoms should be part of the process. Without the relaxation, the pore volume will be overestimated significantly. The transport diffusivity in flexible kerogen matrix is generally higher than in rigid kerogen matrix. The flux is mainly contributed by the adsorbed methane molecules. There is additional flux through the occasionally opened pores in the flexible kerogen matrix.
Evolution of Well Logging Technologies in the Development of Deposits on the Caspian Shelf
Authors: Shtun Sergey , Golenkin Mikhail , Rakitin Mikhail , Shtepin Daniil , Mityagin Artem , Cheprasov Alexey , Golubtsov Ruslan , Kuzakov Vittaly 
Published: October 2018

Abstract
It is difficult to imagine modern exploitation of deposits without drilling horizontal wells. The choice of the direction of drilling of horizontal trunks depends on the study of the deposit, which is based on seismic and exploration data. The drilling conditions onshore is somewhat easier than in the sea, as there are a sufficient number of vertical and horizontal wells on the ground that carry enough information to select the optimal direction of the horizontal production well. There is a completely different situation with drilling offshore production wells. As a rule, there are not enough vertical exploratory wells in the fields located at sea, which make it difficult to develop and operate offshore deposits.
Complex drilling conditions require a deeper and more comprehensive technological approach to the well planning process. Modern technological solutions allow solving a wide range of tasks for obtaining geological information about the field, reducing risks, and, as a result, reducing the time of drilling and completion of wells. In this paper, we describe the range of geological and technological problems that were solved due to the introduction of new technologies for well logging.
Approaches for Petrophysical Modelling and Logging Interpretation of Thin Laminated Achimov Deposits Reservoir
Authors: Fattakhov Emil , Timirgalin Azamat , Zhukov Vladislav , Oshmarin Roman , Mukminov Iskander , Kondratiev Artem 
Published: October 2018

Abstract

Resume
Currently, due to the depletion of terrigenous oilfields with thick reservoirs, more oilfields with worse formation properties are being involved into production. One of the example of such implementation is Achimov layer, which is shaly-sand deposits of deepwater genesis, associated with the fondoform part of clino-cycle on the Neocomian age. Difficult geology aspects, high degree on unexploration contributes to the presence of various problems in the development of these sediments. Some problems also has historical background: in the past Achimov deposits were the transition interval for more deep-located Jurassic deposits which leads to low representativity of core data and narrow complex of logging tools.
Achimov sediments represented by complex anisotropic reservoirs and usually have thin laminations of siltstones and sandstones. Vertical resolution of these laminations could vary from the first centimeters to the first dozen centimeters. Identification of perspective intervals and reliable estimation of their formation properties by the logging is assosiated with a number of difficulties, main of which is insufficient vertical resolution of tools. Althought there are a lot if articles written about laminated sediments, most of them offer solution in up-to-date logging methods and modern logging tools interpretation. Our aim is to extract the maximum amount of information using an existing data set.
Thus, we are faced with the task of finding an approach to petrophysical modeling and interpretation of highly laminated reservoirs depending on the completeness of the input data set.
Well Performance Modeling in Unconventional Oil and Gas Wells
Authors: Oyewole Adeoluwa , Kelkar Mohan , Pereyra Eduardo , Sarica Cem 
Published: October 2018

Abstract
The challenge facing reservoir and production engineers remains ensuring continued production from a well, including additional recovery with artificial lift methods. To accomplish this, means to determine the production performance of a well until the end of its life is desired. This challenge is even greater when dealing with production from unconventional formations. This paper presents a methodology to model the production performance of a well producing from an unconventional oil or gas formation.
Emphasis is placed on the use of readily-available information to production engineers for the day-to-day analysis and optimization of production from the field. For developing the model, traditional flow regimes observed during the production of a well are utilized. Using this information as well as superposition principle, a working model is developed, tested and validated.
Technical contributions of this paper include a procedure to implement this solution in any producing oil or gas well from an unconventional formation, and an Inflow Performance Relationship (IPR) framework for visualizing productivity changes with time of a particular well.
Complex Approach to Fault Description While Geosteering for Maximization Reservoir Contact in Horizontal Wells in West Siberia Oilfields
Authors: Krutko Vladislav Vadimovich , Yurkina Tatyana Alexandrovna , Kushnir Dmitriy Yurievich , Karpov Valery Borisovich 
Published: October 2018

Abstract
The paper presents an interdisciplinary approach to the tectonic dislocations description based on the results of interpretation of seismic data, petrophysical analysis of well-logging data in horizontal wells and the results of inversion of the multifrequency propagation tool. On the materials of seismic surveys and logging-while-drilling data in horizontal wells of one of the oil fields in Western Siberia a cinsistent approach to fault identification and description is presented.
Interpretation of seismic data allows predicting the fault presence along the horizontal well profile and gives preliminary estimation of the dipping and amplitude parameters of the fault surface. Utilizing the the logging-while-drilling data of a group of horizontal wells with the aim to improvement the geological model after fault crossing an approach including machine learning principles is proposed and tested. Application of inversion of the multifrequency propagation tool to one of the updated geological model with faults allowed to improve the estimations of the fault zone parameters.
Industry and University Collaboration Progresses the Concept of a Citizen Engineer
Authors: Battalora Linda A. , Brewer Linda Y. , Chen Jiaheng 
Published: October 2018

Abstract
The Society of Petroleum Engineers Sustainability Task Force (SPE-STF) was created in 2014 and immediately developed Sustainability content including a strategy, curriculum, and course offerings. The opportunity for a collaboration between SPE-STF and Colorado School of Mines Petroleum Engineering (CSM-PE) graduate students was quickly identified with beneficial outcomes for both parties.
Over a three-year period and with SPE-STF guidance, graduate students analyzed a variety of resource plays in global geographic locations and ultimately, the role of the Citizen Engineer in sustainable development. During this timeframe, students worked in multinational teams and researched probable technical and non-technical issues, potential interactions between those issues, and the options for managing those issues. SPE-STF provided feedback to students based on industry experience. SPE-STF and other industry representatives engaged with students in the classroom on topics of health, safety, security, environment and social responsibility (HSSE-SR), sustainability, stakeholder engagement, and risk identification.
In technical memoranda, final reports, and presentations, CSM-PE graduate students defined the role of the Citizen Engineer, provided integrated case study analysis including technical and non-technical risk assessments, recommendations for sustainable development, and the feasibility of the financial business case.
This academic and industry collaboration informed the SPE's growing sustainability conversation on integrating sustainable development into operational business plans and provided opportunity for improved sustainability competency and skill development for employees and students.
Low Tension Foam Flooding for Chemical Enhanced Oil Recovery in Heterogeneous Systems
Authors: Hahn Ruth , Spilker Kerry , Alexis Dennis , Linnemeyer Harry , Malik Taimur , Dwarakanath Varadarajan 
Published: October 2018

Abstract
Current chemical EOR technologies, such as surfactant polymer flooding, have limitations, such as, high temperature, high salinity, and/or low permeability reservoirs. Low tension foam flooding, however, can be performed at high or low temperatures, salinities, and permeabilities. Low tension foam reduces residual oil saturation and increases sweep efficiency. The current literature shows the effect of foam in corefloods and limited 2-D micro-model experiments. We investigate the ability of low-tension foams to successfully divert flow into lower permeability zones in both communicating and non-communicating heterogeneous systems.
During this laboratory study, a surfactant that has shown success for foam applications in the field was evaluated and used as a baseline to compare and evaluate low tension foam formulations. We measured resistance factors under constant pressure and constant flow conditions. In addition, we established benchmarks for flow diversion. The low-tension formulations were modified to display foaming abilities and compared against the baseline surfactant benchmarks. Phase behavior experiments were conducted to determine the oil solubilization ratio of each surfactant formulation. Foam floods with surfactant formulations with favorable solubilization ratios were conducted in heterogeneous systems to determine sweep efficiency and oil recovery.
Surfactant formulations were developed that showed favorable apparent viscosities during in situ foam floods and improved sweep efficiency in a dual-permeability communicating system comparable to the baseline foam. During oil recovery experiments in a heterogeneous system, the baseline surfactant recovered approximately 40% of the remaining oil while the low-tension formulation recovered over 70% of the remaining oil. This study indicates that we can use low tension foams to successfully divert flow from high permeability zones to low permeability zones in heterogeneous sand packs and recover oil at the same time.
Synergistic Effect Between Wormlike Micelles and Nanoparticles in Stabilizing Foams for High Temperature Stimulation
Authors: Zhu Jingyi , Yang Zhaozhong , Li Xiaogang , Wang Zexun , Lu Yanjun 
Published: October 2018

Abstract
As the resulting foam is unstable both thermodynamically and kinetically, its volume decays with time once foam generation is stopped. Lack of stability of these foams often limits their application. The current study attempts to investigate the synergistic effect of using elongated wormlike micelles and silica nanoparticles on foams stability. And foams with better performance as a fracturing fluid can be conducive to efficient stimulation under harsh formation conditions.
First, the stability of static foams was studied using a blend of cationic foaming agent (CTAB) and wormlike micelles zwitterionic surfactant (EAPB) with and without silica nanoparticles. Second, in order to figure out the stability mechanism, bubble size distribution, film thickness, micro structure were conducted by optical microscope and cryo-scanning electron microscopy (cryo-SEM) while free drainage, viscoelasticity and rheology experiments were carried out for confirming the conclusion. Finally, proppant suspension experiment with silica nanoparticles over time was measured at high temperature to verify the synergistic effect between elongated wormlike micelles and silica nanoparticles.
With silica nanoparticles and elongated wormlike micelles, foams exhibited a significant improvement in stability especially at high temperature. As the three main mechanisms operating during and after the production of foams are drainage, coalescence and coarsening, irreversible adsorption on gas-liquid interface of silica nanoparticles could improve the elasticity of foam films and elongated wormlike micelles could enhance the fluid viscosity at the same time. They remarkably delayed above three processes, showing synergistic effect in stabilizing foams, corresponding to uniform and small bubble size, thick foam films, dense micelle structures and slow drainage rate. Under high temperature and shearing stress, the viscosity of foam began to rise at first which may result from the network formation consisting of micelles-nanoparticles junctions. This corresponded to an increase in viscoelasticity when adding silica nanoparticles. However, once association between micelles and silica nanoparticles broke, there was a continued decrease in viscosity. The proppant suspension experiment showed that although free drainage stopped and foams became unstable, the presence of nanoparticles aggregates together inducing traffic jam in Plateau border, slowing the drainage rate which dominates the velocity of settling proppant. Therefore, the settlement of proppant could be hindered because of physical resistance of nanoparticles.
With enhanced performance, foams employed as a fracturing fluid exhibit extraordinary characteristics in terms of stability, rheology and proppant suspension ability at high temperature. It is worth pointing out that nanoparticles will have a broad prospect in stimulation field.