bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of Reservoir Flow Units Based on a Power-Law Equation of Permeability Obtained from an Interacting Bundle of Leaky Tubes Model
Authors: Civan Faruk
Published: October 2017

The conventional approach to flow units’ characterization according to Amaefule et al. (1993) is based on the Kozeny-Carman equation. Although, the Kozeny-Carman equation has been used widely for relating permeability to other properties of porous materials, it suffers from the assumption of non-interacting flow tubes. In this paper, the effects of pore connectivity, valve action of pore throats, and cementation factor are considered by an interacting bundle of tortuous leaky capillary-tubes model of porous media to derive an improved equation of permeability. The parameters of the power-law form of this equation are related to pore connectivity measured by the coordination number using the functional relationships derived from the phenomenological rate equations. The validity and accuracy of this approach is established by comparison with directly measured core data. This approach allows for incorporation of various data within a single, compact, and simple power-law equation over the full range of porosity and permeability. The power law exponent of the leaky-tubes model is shown to deviate significantly from the unity assumed in the Kozeny-Carman equation. While the Amaefule et al. (1993) approach characterizes the reservoir flow units solely based on a flow-zone indicator (FZI) parameter, the present improved approach adds a power-law exponent which allows for enhanced flow units’ characterization using two porosity dependent parameters. The analysis of the permeability vs. porosity data demonstrates that the power law flow units’ model alleviates the deficiencies of the classical Kozeny-Carman equation. This model adequately approximates the actual flow patterns in porous media because it allows interactions and cross-flow between the capillary hydraulic paths.
Optimized Grids for Accurately Representing Geology in Geomechanical Simulations
Authors: Gringarten Emmanuel , Lecuyer Jean Daniel , Villarubias Elsa , Cosson Camille , Li Wan-Chiu
Published: October 2017

To reliably quantify changes in the in-situ stresses due to oilfield exploitation, it is necessary to start from a representative description of the subsurface and simulate both fluid movement and geomechanical effects. For this purpose, a new 3D "hybrid" grid is presented. This grid accurately honors geological features, with no unwarranted simplifications, while being ideally suited for geomechanical simulators and the new generation of flow simulators.

The new 3D Hybrid Grid is dominated by hexahedrons arranged in a structured manner except around faults, where it is made up of tetrahedrons. The grid is constructed from the underlying geological model and the sealed fault network. Both structured (hexahedrons) and unstructured (tetrahedrons) parts follow stratigraphic deposition information. For geomechanical simulations, each compartment is considered as an independent mesh part allowing sliding effects along the faults. At the interfaces between the hexahedrons and tetrahedrons in a fault block, shared nodes are used to ensure stress equilibrium and displacement continuity.

Uncertain states of stress and unforeseen changes in the integrity of the subsurface can have grave economic and environmental consequences. Understanding these helps mitigate development risks, and optimally develop the field. Today, geomechanical studies are not routinely performed and are often based on simplified descriptions of the subsurface. With this new Hybrid Grid, we propose to combine a reliable representation of subsurface with state-of-the art rock mechanics to assess how reservoirs respond to drilling, completion and production. Simplifications in either can lead to incorrect assessment of risks or production forecasts. The grid presented in this paper aims at honoring geology accurately while also being optimal for numerical computations. The zones of tetrahedrons enable the inclusions of even the most complex faulting systems, while the structured hexahedrons precisely follow the stratigraphy and are most efficient for geomechanical simulations.

The gridding technology presented enables a coherent representation of the subsurface for constructing geological models for simulating both flow and geomechanics. Although such meshing schemes exist for modeling manufactured objects, these are difficult to apply to geological formations; our approach now enables them by guiding the meshing using the chronostratigraphic parameterization of the subsurface. It will allow engineers to routinely include the effects of stress changes during production and will build confidence in development plans.
An Innovative and Efficient Approach to Deepwater Well Testing for a Challenging Carbonate Reservoir Offshore Malaysia
Authors: Hosatte Pierre , Anderson Ryan N. , Venugopal Shangkar , Marimuthu Suresh , Bidi Firdaus , McBain Ben , Royce Peter
Published: October 2017

This paper reviews an offshore Malaysia deepwater appraisal well drilled and tested Q1 2016 and presents innovative drillstem testing (DST) solutions specifically engineered and developed to enable efficient deployment, safe production, and successful collection of representative downhole hydrocarbon samples from a challenging carbonate gas reservoir.

The following DST solutions and methodologies are presented: An Open-Hole DST design to address downhole fractured conditions with multiple zones prone to total losses and deployed using pressurized mud cap drilling (PMCD) mode, providing high operational efficiency with no requirements for tubing conveyed perforating (TCP).A subsea safety test tree (SSTT) system operating philosophy and fit-for-purpose subsea well controls contingency procedures to ensure safe emergency shutdown (ESD) and emergency quick disconnect (EQD) from a dynamic positioning (DP) rig.A carefully designed wireless acoustic telemetry system to enable real-time collection of multiple downhole samples of reservoir fluids and real-time bottomhole data transmission for critical decision making.A production shutdown (PSD) system using a state-of-the-art programmable logic controller (PLC) for effective ESD in high-H2S environments.

The DST solutions developed enabled appropriate management of the operational risks identified and provided increased levels of contingencies to guarantee successful and efficient delivery of the well objectives. High-quality downhole samples of reservoir fluids were collected, and the overall key objectives of the well test in terms of reservoir characterization were successfully achieved in a cost effective manner with reduced personnel, health, safety, security, environment (HSSE) and process safety (PS) exposure. This paper showcases how innovative DST solutions, engineered to suit well conditions and combined with fit-for-purpose operational procedures, enabled the safe, efficient, and successful delivery of critical well objectives in a challenging and hostile deepwater environment.
History Matching of Frequent Seismic Surveys Using Seismic Onset Times at the Peace River Field, Canada
Authors: Hetz Gill , Kim Hyunmin , Datta-Gupta Akhil , King Michael J. , Przybysz-Jarnut Justyna K. , Lopez Jorge L. , Vasco Donald
Published: October 2017

We present a novel and efficient approach to integrate frequent time lapse (4D) seismic data into high resolution reservoir models based on seismic onset times, defined as the calendar time when the seismic attribute crosses a pre-specified threshold value at a given location. Our approach reduces multiple time- lapse seismic survey data into a single map of onset times, leading to substantial data reduction for history matching while capturing all relevant information regarding fluid flow in the reservoir. Hence, the proposed approach is particularly well suited when frequent seismic surveys are available using permanently embedded sensors.

Our history matching workflow consists of two stages: global and local. At the global stage of history matching, large-scale features such as regional permeabilities, pore volumes, temperature and fluid saturations are adjusted to match seismic and bottomhole pressure data using a Pareto-based multiobjective history matching workflow. Rather than an artificial subdivision of the domain, the history matching regions are naturally defined based on an eigen-decomposition of the grid Laplacian and a spectral clustering of the second eigenvector (fiedler vector). The global updating is followed by local history matching whereby cell permeabilities are adjusted to further refine the history match using semi- analytic, streamline-based model parameter sensitivities. The power and efficacy of our proposed approach is illustrated using synthetic and field applications.

The field example involves steam injection into a heavy oil reservoir at Pad 31 in the Peace River Field (Alberta, Canada) with daily time lapse seismic surveys recorded by a permanently buried seismic monitoring system (Lopez et al. 2015). In our specific application, we have used time lapse data (in terms of two-way travel time) from a Cyclic Steam Stimulation (CSS) cycle in the pad with a total of 175 seismic surveys. With a single onset time map derived from this data we were able to capture the propagation of pressure and saturation fronts and significantly improve the dynamic model through the estimation of permeability distribution, fluid saturation evolution and swept volume. With this methodology we correctly identified and further refined the location of stimulated zones as inferred before from reservoir engineering judgement and manual adjustments aiding better understanding of CSS behavior in the studied field. The results clearly demonstrate the effectiveness of the onset time approach for integrating large number of seismic surveys by compressing them into a single map. Also, the onset times appear to be relatively insensitive to the petro elastic model but sensitive to the steam/fluid propagation, making it a robust method for history matching of time lapse surveys.
Active Acoustic Ranging to Locate Two Nearby Wellbores in Deepwater Gulf of Mexico
Authors: Poedjono Benny , Alatrach Samer , Martin Albert , Goobie Roger B. , Allen William T. , Sweeney Eugene
Published: October 2017

Salt drilling in Deepwater Gulf of Mexico (GOM) presents unique challenges. One of these challenges is the effect salt has on ranging technologies used in contingency relief well designs. A new technique called Active Acoustic Ranging (AAR) addresses the challenge of locating and tracking the target wellbore to the interception phase. This case study details the degree of precision that this new technique provided while locating two nearby wellbores within salt. This study is intended to improve industry awareness and understanding of relief well ranging options available to the industry, specifically wellbore ranging activities conducted within a salt formation.

Sonic logging started in the early 1930s to determine rock characteristics by measuring the refracted signals from a combination of transmitters and receivers. The technique evolved by recording acoustic signals beyond the refracted zone, by positioning the transmitters and receivers downhole in the logging tool.

AAR utilizes surface seismic processing methods to determine azimuthal direction and distance of compressional and shear acoustic signals, reflected from around the borehole. After processing the reflected signals, the distance and direction of nearby wellbores can be determined. This can be effective in salt formations, where resistivity inhibits use of active electromagnetic ranging tools.

This case study presents test results conducted in a GOM Deepwater operation to locate two nearby wellbores, a cased hole and an open hole, using AAR. It shows that AAR signals can be successful in locating offset wellbores within salt formations. The acoustic signals, both compressional and shear, were recorded using a stack of 13 receivers. Each stack had 8 sector azimuthal receivers to determine the distance and direction of the corresponding target wellbores.

By utilizing compressional and shear signals generated from the various distances of monopole and dipole transmitters, a redundant process was provided to determine the location of the target wellbores with a high degree of accuracy.

In addition, the acoustic images provided estimates of the salt quality, which can be used to select the interception location for hydraulic kills. The maximum ranging distance is dependent on the velocity and attenuation of the transmitted acoustic signals in the traversed formations. Salt typically has higher velocities that will enable ranging at greater distances than other formations.

One of the primary benefits of this technique is the ability to provide two different measurements using monopole and dipole sources to locate nearby wellbores. This reduces uncertainties that may arise when ranging with a system using only a single measurement. AAR benefits from the salt formation, whereas other ranging technologies, i.e. electromagnetic, were not optimized for salt. AAR increases the ranging options in salt formations.
Developing Equations of State for Unconventional Source Rock Fluids
Authors: Allouache A. , Harrison R. , Turek E.
Published: October 2017

This paper outlines a methodology for constructing equation of state (EOS) descriptions and source rock fluid composition correlations to describe the fluid properties of entire unconventional plays, such as the Eagle Ford shale play and the Permian Basin's Delaware Basin Wolfcamp formation. This methodology is tailored to match the quality of the available data in each play.

Sufficient reservoir fluid samples (either recombined companion surface separator samples or downhole fluid samples) with full pressure-volume-temperature (PVT) laboratory studies are required to span the range of fluids found in each play. These data provide the basis for tuning EOS parameters for C7+ pseudo-components and binary interaction parameters.

Source rock fluid composition varies with thermal maturity of the reservoir. The most direct measure of thermal maturity is C7+ mole weight (MW) determined for fluid samples; however, in areas with unstable production, such as slugging or cycling wells, a three-month-average producing condensate/gas ratio (CGR) is utilized as the basis for correlating the composition. The resulting tuned EOS models and source rock fluid composition correlations provide fluid descriptions for forecasting models, well models, artificial lift design tools, and facility models. When combined with proprietary maps of source rock thermal maturity measures, the models discussed here can be utilized to estimate fluid properties for undrilled acreage.
Advanced Well Control using Rapid Cross-linking Polymers
Authors: Nedwed Tim , Kulkarni Kaustubh , Jain Rachna , Mitchell Doug , Meeks Bill , Allen Daryl P. , Edgecombe Brian , Christopher J. Cruce
Published: October 2017

Industry maintains well control through proper well design and appropriate controls and barriers. This has made loss of well control a very low probability event. Currently the final barrier to maintain control is a valve system (blowout preventer or BOP) located on top of wells capable of sealing around or shearing through obstructions that might be in the well (e.g. drilling pipe and casing) to isolate the well. Although the risk is low when proper drilling practices and design are employed, there are still concerns about well control especially for operations in sensitive environments. Adding an additional barrier could alleviate these concerns.

One scenario for well control loss is if the BOP fails to seal allowing drilling fluids and reservoir fluids to flow. We are currently evaluating a concept to respond to such an event and seal leaking BOPs by injecting a liquid monomer and a catalyst below a BOP leak point to form a polymer-plug seal.

Mixtures of dicyclopentadiene (DCPD) and other monomers mixed with a ruthenium-based catalyst cause a rapid polymerization reaction that forms a stable solid. These reactions can occur under extreme temperatures and pressures and withstand significant contamination from other fluids and solids.

Lab studies have shown that DCPD-based polymer plugs can withstand axial stress of 15,000 psi without significant deformation even at temperatures of 200°C and with 20% drilling fluid contamination. For well control, one option is to preposition monomer mixes and catalyst into pressurized cannisters located at or near subsea BOPs while drilling high-complexity wells. Connecting the pressurized cannisters to appropriate ports on the BOP will allow rapid transfer. During a well-control event, actuating valves would rapidly force the monomer mixes and catalyst from the cannisters into the BOP to initiate polymerization. Polymerization reactions can be as short as a few seconds depending on the monomer mix and catalyst. The resulting solid polymer plug will block the leak path to potentially seal the well.

This paper describes the concept details and summarizes the current status of research.
Intelligent Longest Stroke Reciprocating Pumping System for Production and Cost Optimization
Authors: Ghareeb Mohamed , Kennedy Dave , Woo Alvin
Published: October 2017

Worldwide, as conventional oil resources are depleted; reciprocating sucker rod pumping systems are becoming the most common type of artificial lift methods for onshore wells.

With the growing number of sucker rod pumped wells, the value of optimization and cost control is continuously increasing. Oil companies might have different views of the meaning of "Optimization" but the technology driver nowadays is to gather all possible data/ information to control well operation and system performance around the well in one smart well lift system. This smart system will use the gathered information to optimize the well by decreasing lifting costs, increasing production and optimizing the power consumption. This is additional to enhancing the safety by reducing the well site operations to change well running parameters for well optimization. All these will perform automatically without relying on manpower interference at the wellsite and it will not require stopping the well. This will reduce the manpower safety hazard and well downtime,

This paper will discuss the latest technology in sucker rod pumping system regarding the system capabilities as production, depth, optimization, remote monitoring and control. It will share several case histories from different area worldwide showing the benefits achieved by applying the ultra-long stroke length intelligent unit. These novel applications help operators in Producing high volume from deep wells.Reduced OPEX (operating expense) by Minimize Well Interventions, installation, changing units running parameters for well optimization (speed, stroke length and balancing)Reduce friction between rods and tubing (decrease side load) and extending well running life.
Analytical Method for Voidage Replacement Ratio Calculation in Reservoirs With Quasicritical Fluids
Authors: Rosario O. , Hernandez J. C. , Korabelnikov A. I. , Albornett L.
Published: October 2017

Injection Scheme Surveillance in secondary recovery processes is essential to guarantee their best performance. For energy maintenance processes such as Fluid Injection, the Voidage Replacement Ratio (VRR) represents a relevant surveillance factor, not only for fluid balance calculations (Injection vs. Production) but also for its relation to the reservoir energy decline rate.

According to some reservoir complexities (for example, compositional variation vs. depth), accurate calculations for this parameter may require a robust model such as a Numerical Reservoir Simulator and its corresponding working stages. However, by understanding the Essential Reservoir Mass Balance principles, these calculations can be completed with a simpler approach, in a representative manner.

Most VRR correlations consider a Black Oil reservoir fluid behavior. However, some reservoirs will produce considerable deviations in VRR calculations due to variations in thermodynamic properties in the reservoir column, such as compositional variations with depth or near-critical conditions.

In this technical paper, an analytical method is presented in order to determine the VRR for near-critical condition reservoirs and its corresponding results, against its equivalent model using numerical reservoir simulation calculations. This article suggests a workflow considering the existence of both Equation of State and PVT analysis for reservoir volume fluid calculations by the integration of PVT correlation adapted to the type of produced fluid.

The application of this methodology illustrates the advantages of having a tool for the Reservoir Management Surveillance. This approach provides representative VRR estimations in a practical manner, particularly useful for cases when the required resources for Numerical Reservoir Simulations are not available.
A Novel Approach to Rejuvenate Brown Field by Validating Dynamic Model Response with Near-Wellbore Saturation Monitoring
Authors: Mishra Shubham , Natarajan Karthik Kumar , Aggarwal Akshay , Ojha Aditya , Rincon Alexander , Khambra Isha , Kumar Ajit , Agrawal Gaurav , Kakoty Pankaj , Baruah Neelimoy , Dhiraj Sanjay Kumar
Published: October 2017

Oil India Limited's (OIL) operational areas, in Upper Assam-Arakan Basin, are located in a seismically active thrust fault zone (Bora et al., 2010). Multiple stacked layers, highly faulted anticlines and large number of compartments make the structural setting of these fields very complex. In terms of lithology, some of these reservoirs are low resistivity pays, leading to ambiguities in interpretation due to fresh water environment and complexities in evaluation of hydrocarbon-bearing and water-bearing sands (Koithara et al., 1973, Borah et al., 1998).

Greater Nahorkatiya and Greater Jorajan, since the inception of commercial production in the 1950s, have been intensively studied to find prospective sweet spots, perforation intervals for new well locations and potential workover candidates. These forecasts, guided only by dynamic numerical model results, have had mixed results when implemented in the field. A validation of the dynamic model forecasts with near-wellbore saturation logs, can help to reduce uncertainty. This paper describes the success stories in field implementation of workovers, guided by dynamic reservoir model results and cross-validated with Pulse Neutron Tool (Roscoe et al., 1991, Schnorr, 1996) log recordings.

The intricacy of delivering a precise dynamic reservoir model was managed by state-of-the-art seismic-to-simulation workflows, an integrated approach to improve the quality of the geological model and specific analytical techniques to fill in the data gaps. The calibrated model was analyzed for workover opportunities of zone transfer. In zones with high confidence, (i.e. high Hydrocarbon Pore Volume (HCPV), high porosity, permeability, etc., perforation intervals were recommended for hydrocarbon saturation monitoring to confirm the near-wellbore saturation predicted by the model. This workflow was followed in 8 wells which added immense value both technically and economically.

The validation of model predictions with near-wellbore saturation was carried out in old wells which helped in making informed decision about tapping bypassed hydrocarbon pockets. It helped to avoid non-hydrocarbon bearing zones, which were removed from the existing workover plan. Moreover, it introduced confidence in the dynamic model which will be used in future for more aggressive economic development of the fields. This approach resulted in better understanding of the reservoir characteristics which led to identification of some potential reserves which could be characterized as "Reserve Growth".
Degasification by Absorption-Based Gas Stripping
Authors: Crawford Steve , Korpiel John , Velastegui Oscar
Published: October 2017

A fouling-resistant gas stripping technology was tested for removing dissolved gas species from dirty water streams such as produced water. The CoStrip™ degasifier uses a countercurrent stream of microbubbles to absorb gas species from the water stream into a stripping gas. The microbubbles act as carriers, removing dissolved gases such as hydrogen sulfide (H2S), carbon dioxide (CO2), and BTEX (Benzene, Toluene, Ethylbenzene, and Xylene) compounds. The technology is able to treat water with a high level of suspended solids and oils, which would otherwise clog a conventional packed tower or sieve tray gas stripper. A pilot test was conducted on heavy oil (API-10 to 12) produced water in California, which demonstrated a variety of benefits. The benefits of a degasifier installed upfront of a produced water treatment train include: dissolved gas removal, safe use of open-top equipment downstream due to H2S reduction, lower downstream chemical consumption and sludge generation due to dissolved gas removal, corrosion mitigation, and improved downstream membrane longevity.
The Study of Gel Conformance Control Effect within Carbonates with Thief Zones by Advanced NMR Technique
Authors: Alshehri Amar J. , Wang Jinxun , Kwak Hyung T. , AlSofi Abdulkarim M. , Gao Jun
Published: October 2017

Carbonate's extreme heterogeneity in the form of fracture corridors and super-permeability thief zones challenges the efficient sweep of oil in both secondary and tertiary recovery operations. In such reservoirs, conformance control is crucial to ensure injected water and any EOR chemicals optimally contact the remaining oil with minimal throughput. Gel-based conformance control has been successfully applied on both sandstone and carbonate reservoirs. Achieving effective in-depth conformance control in high-temperature reservoirs, however, remains a challenge due to severe gel syneresis and significant reduction in gelation time. The first step to improve the performance of gel in these challenging environments is the accurate understanding of gel conformance control mechanism inside reservoir rocks.

In this work, a laboratory study was conducted to evaluate a polyacrylamide/chromium gel system for application in a high-temperature and high-salinity (HTHS) carbonate reservoir. Oil displacement experiments on carbonate core samples, combined with nuclear magnetic resonance (NMR) measurements were performed to demonstrate oil recovery improvement by gel treatment and illustrate the mechanisms of the improvement. In these tests, the gel solution was injected into specially prepared heterogeneous carbonate composite core samples, in which different configurations of high-permeability channels were created. Gel treatment was conducted after waterflooding and was followed by chase waterflooding. Oil recovery improvement by gel treatment was 18% of original oil in core (OOIC) in the composite core with high permeability channels extending mid-way through the composite while the improvement was 38% OOIC in the composite core with channels extending all the way through the composite. Detailed spatial fluid variations inside the core samples before and after gel treatment were closely monitored using advanced low-field NMR techniques. Heavy water (D2O) was used in place of water to enhance the contrast between oil and brine for NMR by eliminating the protons in the aqueous phase. NMR measurements indicated that the bypassed oil during waterflooding was effectively recovered after gel treatment.

Results in this study demonstrate the potential of the studied gel system and its favorable impact on sweep efficiency improvement application in HTHS carbonate reservoirs. The NMR study enhances our understanding of how gel helps improve sweep efficiency of subsequent floods through blocking/reducing the permeability of highly-conductive zones.
Interpretation of Interwell Chemical Tracer Tests in Layered Heterogeneous Reservoirs with Crossflow
Authors: Shen Tong , Moghanloo Rouzbeh Ghanbarnezhad , Tian Wei
Published: October 2017

This paper presents a systematic approach to evaluate limited crossflow between layers of a stratified reservoir using interwell chemical tracer test. Previous studies either entail no crossflow between layers or assumes an established vertical equilibrium across transverse direction (owing to viscous/capillary/gravity driving mechanisms); however, they fail to detect the presence of limited crossflow between layers through a ‘bridge’; ‘bridge’ in this study is defined as apathwaythrough which crossflow takes place with an adjacent layer. Obviously, crossflow may take place through several bridges along a layer.

A new formulation is developed to study and detect the limited crossflow. The crossflow is detected through monitoring of the fraction of total injected fluid that arrives at the producer from each layer as a function of time. We employed both numerical simulation and field examples to verify the proposed method. A transition period is identified during which thefraction of injected fluid flowing through each layer significantly changes because of crossflow. Our results indicate that tracer can be used to evaluate number of bridges. The distance between injector and the bridge location can significantly change the interwell tracer results. Identification of crossflow between layers and evaluation of transition zone significantly improves the current efforts to understand reservoir complexity and sweep efficiency. The outcome of this research can help design more successful EOR processes.
Impact of Relative Permeability Hysteresis on Water-Alternating-Gas WAG Injectivity: Modeling and Experimental Study
Authors: Chen Yuguang , Wu Stanley , Zhou Dengen , Chawathe Adwait , Inouye Art
Published: October 2017

Gas injection is a proven enhanced oil recovery (EOR) process, representing the leading EOR-technique in the United States. In recent years, gas EOR technologies are expanding to more challenging (deeper and tighter) reservoirs. In gas injection, there are two basic techniques – continuous gas flooding and water-alternating-gas (WAG) injection. The WAG injection promises improved sweep efficiency, with water being used for mobility control and stabilizing displacement fronts, but suffers from injectivity loss due in part to gas trapping. This injectivity loss can have a major impact on project economics. In this work, we study the modeling of relative permeability hysteresis and its impact on WAG injectivity under both immiscible and miscible conditions.Core flooding experiments are also performed and simulated to understand and quantify the WAG injectivity. Our study showed that the most significant impact of gas relative permeability hysteresis on WAG injectivity lies in the water injectivity reduction following gas flooding. Experimental results confirmed the reduced water injectivity, and this effect can be modeled and sufficiently captured by the gas relative permeability hysteresis.
Blended Learning for the Early Career Population: The Good, the Bad, and the Ugly - Post Appraisal of Results
Authors: Ermel Y. M. , Espinel Diaz A. L. , Yi S. , Lehmann T.
Published: October 2017

Chevron has addressed the challenge of providing global learning opportunities for the early career development employees in a cost constrained, budget restricted environment. One solution was to pilot the blended learning versions of Petroskills' Production Operations 1 and Applied Reservoir Engineering. This presentation is a case study of sessions that were completed in 2016 and 2017.

Using industry approved content from two production and reservoir engineering courses, blended skill modules were developed to cover all key aspects of the traditional instructor-led course. Each module uses the most effective mode of delivery, including videos, narrated slideshows, interactive exercises, reading assignments, and live virtual instructor led sessions. Based on competency models, knowledge is transferred and assured with pre-assessment and post assessment testing. Learners advance at a pace that suits their work situation and learning style. The blended method delivers content that is relevant to current job roles, just-in-time.

The primary benefits of blended learning observed from the two pilot sessions are 1) reduced expenses, travel, and days away from work, 2) increased flexibility in learning styles and schedule preferences, 3) optimized learner's use of time and knowledge with test-out option, 4) metrics to prove learning occurs via pre and post assessments, 5) allowed for networking and communication among learners, 6) longer time to digest the material and retain knowledge according to adult learning principles. Key learnings are to engage internal stakeholders early and often, emphasize the message that this type of learning requires learners to take ownership of the course schedule, and leverage internal metrics (i.e. scorecards) to not only keep learners on track but to also improve quality of skill modules. Change management is a key component to a successful blended delivery.

This approach to blended learning is a relatively new concept for both oil and gas operators and learning and development organizations. The methodology and lessons learned presented in this presentation will benefit others who are evaluating the feasibility of incorporating blended learning into their organizations.
Assessing Single EOS Predictability using PVT Properties of a Wet-Gas Reservoir on a Compositional Simulator
Authors: Ghamdi Bander N. , Tacha Cesar Pardo
Published: October 2017

Understanding the physical properties of gas reservoirs is important for field development and operational planning. Common compositions making up the fluids stream such as methane and heptanes-plus have a direct relationship with reservoir type and performance. The concentration of light and heavy components has essential relationships with saturation pressure and condensate-gas-ratio. An Equation of State (EOS) is expected to have the least error in these two properties to be considered predictive. The aim of this paper is to enhance the analysis process for fluid characterization by appraising the PVT properties, and assessing the predictability of a single EOS for a wet-gas system.

With the development of sophisticated simulation models, consistency of fluid properties have become an essential indicator for quality and accuracy. In this paper, a workflow is presented to evaluate a single EOS with data validation to examine anomalies, validating experimental values against calculated properties, and predicting properties of new samples. Fundamental relationships guided the workflow to extend the data examination spectrum, which contributed to the arrival at the best reservoir fluid characterization. The added value of the approach was significant; the results have shown consistency and applicability to various types of reservoirs to reach optimum fluid characteristics conclusions.
Sequence Stratigraphic Characteristics of Fluvial Facies in the Guantao Formation of South Gentle Slope Belt, Huanghekou Sag
Authors: Chen Rongtao , niu Chengmin , Wang Qingbin , Shi Xinlei , Guo Xuyang , Wang Feilong , Liao Xinwu , Qin Runsen , Xu Zhongbo
Published: October 2017

Through the comprehensive analysis of the data related to cores, logging and seismic, the author holded that there were two kinds of sedimentary systems in the study area, which were braided river deposits and meandering river deposits. According to the sequence stratigraphy method of fluvial facies proposed by Catuneanu et al, we established sequence stratigraphic framework in the Guantao formation of south gentle slope belt, Huanghekou Sag. It was divided into 2 third-order sequences, named as SQGU and SQGL, each of the third-order sequences contains a high accommodation systems tract (HAST) and a low accommodation systems tract (LAST). On this basis, the author summarized the sedimentary sequence evolution characteristics in the Guantao formation of south gentle slope belt, Huanghekou Sag. In the period of LAST in the SQGL, there were mainly composed of braided river facies in the study area, main developed multistage compound sand body. In the period of HAST in the SQGL, there were mainly composed of meandering river facies in the study area, main developed isolated point bar sand body and a high proportion of flood plain mud. The evolution characteristic of the SQGU was similar to the SQGL. Because of the accommodation space of the SQGU was at a high level, the grain size of sandstone and the percentage of sandstone are smaller than SQGL.

It is generally accepted that it was mainly composed of braided river facies in Guantao formation of Huanghekou Sag, difficult to form oil and gas reservoir due to lack of mudstone cap rock. The exploration of Guantao formation has not attracted enough attention. Through this analysis, the author thinked that two sets of meandering river deposition can provide partial sealing and created conditions for oil-gas accumulation in the Guantao formation of south gentle slope belt, Huanghekou Sag. Under the guidance of this research, we have obtaineda certain oil and gas discovery in the study area.
GOR and Water Cut Allocation of Wells in a Complex Riser Test System Using Analytical Techniques
Authors: Thompson Edidiong
Published: October 2017

The measurement of fluid rates while producing from deep-water hydrocarbon reservoirs has been an important aspect of reservoir depletion decisions as it clearly affects the development plan for that reservoir. It is pertinent that rates are correctly allocated for efficient reservoir surveillance.

With the complexity of measuring a three phase flow, produced GOR and water cut must be accounted for to take good decisions in production routing options & reservoir management and handling.

A simple riser test incorporating the use of Multi Phase Flow Metering in individual wells is carried out to allocate production rates to the wells, though it only considers the present production scenarios. The technique ignores production performance history, dynamics of the producing reservoir, flow line system hydraulics, riser routing designation possibilities. This depicts inadequate representation of allocation.

This work presents an analytical evaluation of complex riser tests carried out for wells routed through the risers to the surface to cover for inaccurate Multi Phase Flow Meters (MPFM) measurements. This technique of weighted average analytical process with few counterintuitive properties, as captured in Simpson's paradox used sum of well rates comparism with FPSO readings to derive the "Well MF-d" formula to get deviation factors. The performance trends presented graphically are assessed to get final well meter factors for correcting the MPFM measured rates and the GOR calculated.

From this work, the GOR and Water cut for each producer in the Reservoir XY-1 were correctly allocated. The results showed that 59% of the well counts were dry wells and meter factors ranging from 0.72 to 1.67 were used to calculate well GOR. The Well MF-d formula can always be used to get correct allocation to wells with Multi Phase Flow Meters.
Fuzzy reporting as a way for a company to greenwash: perspectives from the Colombian reality
Authors: E. Contreras-Pacheco Orlando , Claasen Cyrlene
Published: October 2017

Drawing on the legitimacy theory framework, this study introduces an alternative means to spot “fuzzy reporting” signals as a way to detect greenwashing at the firm level. Its approach is based on the way the sustainability reporting process can mislead stakeholders after critical incidents take place. In order to do so, a single environmental incident, which took place in Colombia, is analyzed in light of what happened before, during and afterwards, with special emphasis on the corporate disclosure process performed by the company involved. Results obtained give support to the assumption that fuzzy reporting can be objectively detected not only through the analysis of annual sustainability reports, but also by tracking other forms of corporate messages when a specific concern is carefully followed. This study’s contribution is two-fold. First, it builds on the theoretical notions of greenwashing and fuzzy reporting by illustrating a practical and objective way to identify some deceiving corporate practices. Second, it empirically evaluates this approach in a sensitive context in order to obtain better illustration and prepare the groundwork for further studies.
Relationship of generations X, Y, Z with new communication technologies
Authors: Grenčíková Adriana , Vojtovič Sergej
Published: October 2017

At present times, the impact of new technologies on job creation is going to be a serious problem in personnel management. In the human resources contents, this issue still remains in minor attention. As a result of new communication technologies development in the near future, we will be facing too many changes in working patterns and demands on staff regarding job requirements. Simultaneously with the above stated changes on labor market, a new generation of workers is emerging that grew up with the development of communication technologies, they profess different lifestyle from the one the generations have had before. Many of these generations become employers and bring new approaches to employment of people being different from traditional working patterns. Despite the facts being alleged in this study, it is difficult to estimate to what extent those changes will affect Slovak labor market. Gradual development of technologies is an ongoing process in Slovakia as well and in four years robotics is to be a key technology in most manufacturing plants mainly in automotive industry. Currently, three generations are present on labor market that may have a different approach to changes being implemented nowadays. In this study, the authors analyze the survey results on the use of communication technologies by Generations X, Y, Z, and their abilities to be prepared for changes on labor market. Survey provides interesting information about the access of different generations to communication technologies and their relationship with technical innovations.
A 2D-3D non-contact anthropometric method for daily dressing state-takes young Asian women as example
Authors: Sun Ke Ke , Chiu Yi Jui , Chen Yi Cheng , Wang Yu Xiu
Published: October 2017

Taking young Asian women as research object, this paper is to develop a 2D-3D non-contact body measurement and calculation method for daily dressing state used to generate the CWH (chest, waist, and hip) circumferences suitable for garment practical applications. The general research approach is ‘analyzing related curves of human body, finding their fitting functions and length calculating formulas through mathematical analysis and measuring experiment with large number of samples – extracting effective feature points data in daily dressing state by dynamic and static experiments – calculating such dimensions as width and thickness after curve fitting – generating CWH circumferences via formulas and making comparison’. The numerical results validate the 2D-3D method presented in this paper as a useful and effective approach. Being different from other 3D non-contact measuring methods, the authors provide a new way to get the CWH measurements in the condition of daily natural dressing, which not only optimizes the non-contact anthropometrics theory, but also breaks the static measuring mode. Furthermore, the bringing forth of the concept of ‘daily dressing state’ and the laboratory experiments of this paper would be worthy for practical use.
Dynamic behavior of a vehicle with rear axle compliance steering
Authors: Xu Xiao Mei , Jiang Yi Ping , Chen Ning , Lee Heow Pueh
Published: October 2017

Rear axle compliance steering (RACS) is a technology of passive four-wheel steering, which is designed to improve the vehicle handling and stability at medium or high speed. This paper focuses on the dynamic behavior of the vehicle with RACS. Firstly, the compliance steering principle for different rear suspensions is illustrated. Then, the viscoelastic members with fractional order derivative properties are introduced into RACS, and the fractional order model of RACS is formulated. Next, the dynamic model of the vehicle with RACS is established, the adjusting rules for the compliance steering stiffness are derived, and the vehicle stability is investigated. Finally, numerical experiments are performed to illustrate the effects on the vehicle dynamic behavior caused by the compliance steering stiffness, the viscoelastic members and the vehicle longitudinal velocity. Research results show that, the vehicle with RACS has better dynamic characteristics than that without RACS at medium or high speed; and the compliance steering stiffness, the viscoelastic members and the vehicle longitudinal velocity have different impacts on the vehicle lateral dynamic behavior.
Shooting method for free vibration of FGM Reissner-Mindlin circular plates resting on elastic foundation in thermal environments
Authors: Li Qing-Lu , Luan Wei-Di , Zhu Zuo-Quan
Published: October 2017

This paper presents a free vibration analysis of functionally graded Reissner-Mindlin circular plates with various supported boundaries in thermal environments. A FGM consisting of metal and ceramic was considered in the study. Based on the geometric equation, physical equation and equilibrium equation of thick plate, taking into account the transverse shearing deformation, the free vibration equation of the axisymmetric FGM moderately thick circular plates was derived in terms of the middle surface angles of rotation and lateral displacement. The material properties of the plate were assumed to vary continuously in the thickness direction according a power law. By using shooting method to solve the coupled ordinary differential equations with different boundary conditions, the natural frequencies of FGM thick circular plates were obtained numerically. The effects of material gradient property, thickness ratio and boundary conditions on the natural frequencies were discussed in detail.
Time-frequency analysis method of bearing fault diagnosis based on the generalized S transformation
Authors: Cai Jianhua , Xiao Yongliang
Published: October 2017

The generalized S transform (GST) can flexibly adjust the change trend of the fundamental window function according to the frequency distribution characteristics and the time-frequency emphasis of vibration signal. Also, this transform can accelerate or slow down the time-band width change along with the frequency, in order to make the amplitude of the fundamental window function present the various nonlinear changes. These features are very constructive significance for signal analysis and processing. A time-frequency analysis method based on the generalized S transformation is introduced to the fault diagnosis of bearing. And the application principle and the steps of method applied in fault diagnosis are given. Simulated signals and the actual bearing fault signals from inner race, outer race and rolling body are processed to verify the validity of the proposed method. Results show that the method can effectively enhance the resolution of vibration signal not only in time domain but also in frequency domain. The fault characteristic frequency can be extracted from the reconstructed signal, and the status of bearing and the fault type of bearing can be obviously distinguished. The presented time-frequency method effectively improves the accuracy of the fault diagnosis of bearings.