bluuebunny/crossref_metadata_2025 huggingface dataset:
Integrated Static and Dynamic Uncertainties Modeling Big-Loop Workflow Enhances Performance Prediction and Optimization
Authors: Kumar Sarwesh , Wen Xian-Huan , He Jincong , Lin Wenjuan , Yardumian Hrant , Fahruri Irvan , Zhang Yanfen , Orribo Jose M. , Ghomian Yousef , Marchiano Iryna Petrovska , Babafemi Ayanbule
Published: February 2017

Reservoir simulation is a widely accepted tool for assessing the impact of uncertainties on upstream investment decisions. Currently, the most widely used workflow addressing these uncertainties is a traditional two-step approach: 1) geoscientists performing static uncertainty analysis with earth modeling parameters and selecting a few representative geological models (for example, low-mid-high); 2) reservoir simulation engineers conducting dynamic uncertainty analysis with dynamic parameters combined with the pre-selected geological models and performing history matching, forecasting, or optimization. In this workflow, all the geological uncertainties are lumped into one parameter (the grid) for use in the second step. This severely reduces the flexibility for considering a wider range of alternative static realizations, and thus may bias the history match and forecasts. We implemented an integrated workflow, called "big-loop" that unifies the two-step approach into a single step. This allows for simultaneous and explicit analysis of both types of uncertainties and improvement in reservoir management decision quality. It also allows for direct modification of earth model parameters to achieve a history match with geological consistency. Although the concept is not new to the industry, it is rare to find references of field applications of the "big-loop" workflow. We present the applications of this workflow to both green and brown reservoirs to demonstrate its value in improving accuracy and efficiency. In a Gulf of Mexico green field, the workflow is applied for uncertainty analysis of static parameters (for example sand channel width and salt body extension) and dynamic parameters (for example rock-fluid properties) for probabilistic Original Oil in Place (OOIP) assessment and production forecast. The workflow facilitates the design of uncertainty resolution, upside capture and downside mitigation plans. In an onshore fractured reservoir, the workflow is applied for simultaneous history matching using static fracture parameters (fracture length and aperture) and dynamic parameters. The workflow improves the model accuracy and decision quality for the upcoming IOR/EOR development project. In an offshore gas field, the workflow is used to perform experimental design (ED) studies with static and dynamic uncertainties. This systematic & automatic workflow eliminates manual inputs and reduces the need for recycles. Finally, in another field, the workflow is used to perform probabilistic history matching using static and dynamic parameters. This workflow is capable of delivering a full-cycle solution for uncertainty assessment and probabilistic history matching with high efficiency and high quality results.
Nonlinear Safeguarding Strategies for Fully Implicit Timestepping and Complex Processes
Authors: Lutidze Giorgiy , Younis Rami M.
Published: February 2017

This work develops the theoretical basis for a promising safeguarding strategy that is applicable to improving the robustness and efficiency of Newton-like methods for general physics implicit reservoir simulation. The method is demonstrated for a range of models with growing complexity, including thermal compositional problem, and is compared to state-of-the-art alternatives.

The damping algorithm is based on viewing the Newton iteration as a forward Euler discretization of the Newton flow equations. Three alternative a posteriori local discretization error estimates are developed. The first and second is are based on computable estimates of the norm of the derivative of the Newton step with respect to step-length. This estimate provides an accurate measure of the departure from the Newton flow path. The third estimate is based inspired by Richardson extrapolation idea. We propose to control the Newton step length by limiting the estimated local discretization error. The control strategy is conservative far from the solution, and can be shown to result in the standard Newton method otherwise.

Computational results are presented for a series of simulation problems with increasing complexity. First, results for two phase flow simulations demonstrate that the proposed method is competitive with, but not superior to current state-of-the-art strategies. For thermal, reactive, and multicomponent problems the method is compared to line-search methods. Superior robustness and computational efficiency are observed, and the iteration converges for significantly larger time-step sizes. These comparisons show that absent of tailored ad hoc strategies such as those recently proposed for black oil simulation, the proposed strategy is more robust and efficient than the current state-of-the art. This is demonstrated by testing the required number of iterations to convergence for different time-step sizes as well as during the course of full simulations.

While several novel Newton damping strategies and alternative discretization with improved differentiability have been proposed and successfully demonstrated for multiphase flow simulation, this work provides a first step towards tailored robust safeguards for complex physics.
A Massively Parallel Semicoarsening Multigrid Linear Solver on Multi-Core and Multi-GPU Architectures
Authors: Manea A. M. , Tchelepi H. A.
Published: February 2017

In this work, we have designed and implemented a massively parallel version of the Semicoarsening Multigrid Solver (Schaffer 1998), which is capable of handling highly heterogeneous and anisotropic 3D reservoirs, on a parallel architecture with multiple GPU's. For comparison purposes, the same algorithm was also implemented on a shared-memory multi-core architecture. The implementation exploits the parallelism in every module of the original Multigrid algorithm, including both the setup stage and the solution stage, without modifying the original algorithm basic steps. The benefits of this approach are twofold: maintaining the inherent strong linear convergence of the serial Multigrid algorithm, and making advantage of the shared-memory architecture to minimize the need for communication.

The design of the algorithm uses a combination of plane relaxation and semicoarsening to efficiently handle anisotropies in 3D, (Dendy et al. 1989). Since the z-direction in most reservoir models is a direction of strong-coupling compared to the x- and y- directions, semicoarsening is employed in the z-direction, and plane relaxation is used for relaxation on x-y planes. Besides the need to solve 2D-systems for plane-relaxation, a set of 2D systems must be also solved on each multigrid level during the setup stage to get an approximate representation of the exact prolongation operator described in Schaffer (1998). For handling both types of 2D systems, a massively parallel version of the 2D Black Box Multigrid (Alcouffe et al. 1981) was designed to handle those 2D solves. To be able to handle problems involving high anisotropies in the x- and y- directions, the 2D Black-Box Multigrid uses alternating line-relaxation with zebra ordering to parallelize across multiple line solves. Due to the inherent granularity difference between the GPU threads and the multi-core threads, line-relaxation was designed to use Thomas Algorithm on the multi-core architecture and Parallel Cyclic Reduction (NVIDIA Corporation 2014b) on the GPU architecture. In both the 3D Semicoarsening Multigrid and the 2D Black-Box Multigrid, V-cycling was used to avoid spending more time at coarser levels and thus affecting the parallel efficiency. To minimize the expensive communication between the host and the GPU (and amongst GPU's), every 2D-solve is explicitly handled by a single GPU.

The two versions of the solver were tested using various highly heterogeneous multi-million-cell problems derived from SPE10 Second Dataset Benchmark. For problems with sizes large enough, the GPU implementation, running on KEPLER-Based K40c cards, is found to be always faster than the multi-core implementation running on 12 Intel® Xeon® E5-2620 v2 2.10 GHz cores. In addition, the inherent serial nature of multiplicative multigrid, along with the approach taken to minimize the communication through PCI-e, were found to limit the scalability beyond 3-4 cores/GPU's.
Drill and Learn: A Decision Making Workflow to Quantify Value of Learning
Authors: Hanea R. G. , Casanova P. , Hustoft L. , Bratvold R. B. , Nair R. , Hewson C. , Leeuwenburgh O. , Fonseca R.M.
Published: February 2017

The goal of reservoir management is to make decisions with the objective of maximizing the value creation from the oil or gas production. In order to do this models that preserve geological realism and have predictive capabilities are being developed and used. These models are commonly calibrated by using Assisted History Matching (AHM) methods which, in general, will lead to reduced uncertainty in the predicted production. Although uncertainty assessment and reduction is often an element of high-quality decision making, it is not, in itself, value-creating. Value can only be created through decisions and any decision changes resulting from AHM should be modeled explicitly. Recently there has been a spurt in the application and understanding of Value of Information workflows for reservoir management. In this talk we present a comparison of existing workflows and point out the differences between them. Following this we introduce, a practically driven approach, referred to as Drill and Learn, with elements and concepts from existing workflows to quantify the Value of Learning. The difference and definitions of Value of Information and Value of Learning (VoL) are also presented. Ensemble methods (ES-MDA and StoSAG) are used for the history matching and optimization. The results presented are obtained by applying the proposed Drill and Learn workflow on a realistic synthetic case. Sensitivities to the amount of information obtained before a closed loop exercise is performed are also investigated. We show the benefit of performing the closed loop approach to quantify the value of learning (VoL) to modify field development decisions which leads to a mature robust decision making framework.
A Comprehensive Computational Framework for Long Term Forecasting on Serious Wellbore Damage and Ground Surface Subsidence Induced by Oil and Gas Reservoir Depletion
Authors: Liu Ruijie , Liu Zhijun
Published: February 2017

Depletion of oil and gas reservoirs results in ground surface subsidence and wellbore damage. Accurate prediction of subsidence and wellbore damage can provide a strong support to reservoir management and community precaution on subsidence impact. For reservoirs with soft rock formations, depletion-induced reservoir compaction results in serious damage and permanent deformation of rock formation. Cap plasticity models are crucial to achieve a more reliable prediction on the compaction of reservoirs with soft rocks. In this study, we develop a fully coupled and fully implicit finite element framework along with cap plasticity models for modeling the compaction of reservoirs with soft formations undergoing finite deformation. Creep models are also formulated with cap plasticity models for predicting the long-term effect of reservoir compaction. A material integrator for stress return mapping for both plasticity and creep models is consistently formulated to achieve fast convergent rates. A reservoir compaction model with three horizontal production wells and a wellbore damage model are solved using the proposed computational framework as well as cap and creep models with parameters obtained from field tests. We have demonstrated: 1) a good performance of the proposed computational framework in modeling the compaction of soft rock reservoirs with complex payzone geometries; and 2) the predicted subsidence with cap plasticity models could be seven times greater than linear elastic or plasticity models without caps.
Optimizing CT Material Properties for Extended Reach Operations
Authors: Newman Ken , Kelleher Patrick , Gunby Brian
Published: February 2017

There is a demand in the industry for coiled tubing (CT) that can safely reach significantly farther in horizontal wells than the current, steel based technology can reach. Some have suggested that CT composed of lighter materials could maintain a neutral or positive buoyancy (floating) in the horizontal section and thus be capable of reaching extraordinary total depths without exceeding their yield limit. However, several other aspects of CT operations must be considered for a complete assessment of extended reach capability, and these aspects often cause lighter materials to friction lock at shallow depths relative to their steel counterparts.

Using a parametric analysis, this paper will quantify the effect material properties, including stiffness and density, have on CT performance in extended reach wells. It will also correlate those properties with materials available today such as steel, titanium, and composites to explain why steel tubing is used in most CT operations.
Real Time Fatigue Endurance Monitoring of Open Water Coiled Tubing Downlines
Authors: Tipton Steven M. , Xie Bin
Published: February 2017

Coiled tubing was utilized as a conduit-type riser to deliver high-pressure fluids from a rigless multi-service vessel (MSV) during a GOM multi-well treatment campaign. The campaign consisted of high pressure pumping into a number of subsea wells for extended durations. The coiled tubing (CT) downlines are deployed with a clump weight through open water and connected to the subsea safety module and well stimulation tool.

The depths of these operations were on the order of 1,372m (4,500 ft) and quite similar (±100 ft). Fluids (including acid) were pumped continually through the conduit at pressures up to 10,000 psi for extended periods of duration (on the order of several days) from the MSV to the fixed subsea safety module. Waves and currents impose pitch and roll on the MSV, along with the need for continual dynamic repositioning. This motion causes discrete wrapping and unwrapping at the point where the tubing just exits the sheave (the "hot spot"). This leads to elastic strain fluctuations that can lead to significant high cycle fatigue (HCF) damage.

The MSV must continually adjust its heading for optimal metocean response. A unique system was designed and implemented to coordinate this positioning with minimized CT HCF damage accumulation. The system uses a robust position transducer to provide continual input about the critical components of vessel motion. This information is used by a program to compute the near real-time dynamic stress response of the tubing at the hot spot and the corresponding HCF damage accumulation, along with the low cycle fatigue (LCF) damage accumulation that occurs along the entire length of the tubing as it is deployed during each job. The system facilitated the management of multiple jobs, assuring that hot spots were not over-exercised from job to job. This was important due to the similar depths of the wells. The hot spots were tagged with paint to confirm their location.

The mechanics underlying the fluctuating stresses at the hot spot are described along with how these are computed from the MSV motion. Post campaign fatigue testing was conducted to validate the residual life in the tubing, as predicted by the program.
Fishing More Than 3,000 Meters of 1-3/4-in Coiled Tubing A Case Study
Authors: Merchan A. , Lopez A. , Deolarte C. , Sosa M. , Franco E. , William A. , Rodriguez F. , Ponce G. , Cervantes J. R.
Published: February 2017

We describe the situation and challenges, the implemented process and strategies, and the downhole tools used during the remedial work to successfully recover 3041 m of 1 3/4-in coiled tubing (CT) pipe lost-in-hole during an acidizing job.

During an acidizing job through the CT string as a part of a workover job in a well of a mature field in offshore Mexico, after filling the pipe with acid, the CT operator was ready to spot it across the perforated interval. When the up-hole movement started, the CT weight reached approximately 36,000 lbf (normal pulling weight at that depth in the previous runs) and then the CT weight went to 0 lbf. After retrieving the pipe to surface, it was noticed that only 199 m of CT were recovered from the well, leaving +/- 3041 m of CT pipe inside the hole. After a total of 43 runs and over 20 days, the entire CT string including the Bottomhole assembly (BHA) was recovered, and the well was put back on production. The key was to conform the top of the fish with a downhole motor equipped with a milling shoe, and then exploit the versatility and fast rig up/down capabilities of slikcline to position the fishing tool on the top of the fish. After the fish was latched, a GS profile was left in hole, thus allowing the CT to latch and retrieve the entire fish.

Fishing operations are considered more an art than a science because of all the variables involved, for example, type and top of the fish, restrictions along the wellbore, available fishing equipment, pulling capacities, and so on. However, following industry best practices, fishing can switch from a nightmare to a useful learning and successful experience. The authors will summarize the milestones in the operation, which serves as an example of collaborative work between the operator and service company that led to a successful outcome.
How to Perforate Challenging Wells Completed in Two Casing/Liner Overlap Sections: Mature Ecuador Field Case History
Authors: Alvarez Jhonny , Naranjo Edwars , Agila Cynthia , Castillo Rommel , Cuenca Dario
Published: February 2017

One of the primary challenges for wellbores completed with overlap sections in prospective pay zones is determining how to establish effective communication between the wellbore and reservoir. Conventional perforations are not sufficient to initiate production. This paper presents an effective method for communication with the reservoir using cutting or slotting tools.

Based on Bernoulli's energy conservation principle, an abrasive fluid, primarily composed of gel and silica sand, is forced through jets under a predetermined pressure, converting pressure energy into kinetic energy and enabling the fluid to exit the jets at velocities exceeding 1/2 Mach; this enables the abrasive cutting of the production liner/intermediate, cement sheet, and formation rock. This technique can be applied with either coiled tubing (CT) or jointed pipe, thereby achieving success in different applications, such as perforations in a single casing, overlap casing sections, and before hydraulic fractures.

A value-added element of this perforation technique includes the application of a relative-permeability-modifier (RPM) additive as part of the abrasive fluid, which helps prevent formation fluid loss while jetting under high overbalance pressures in low-pressure wells. This paper describes the job design, oil-production expectations from the operator, operational data, simulations, skin analysis, and results of this case. The technique was designed and individually applied in two target sandstones, Reservoirs A and B, which are coincidentally located on both 9-5/8 × 7-in. and 7 × 5-in. overlap sections, respectively. The method enabled a customized design for each zone, which resulted in more aggressive perforations to overcome the challenge in both sections.

Successful production improvement for a mature field in Ecuador was achieved using this perforation technique, which was the only available solution at the time to overcome such challenges. Advantages and lessons learned are discussed and compared to conventional gun-based perforating techniques. Another interesting factor of this case history is that Reservoir B was new, with unknown fluid and petrophysical properties.
Electric-Line Milling Operation on Tree Master Valve of a High Surface Pressure Well Enables Well Control
Authors: Al-Ajmi Mohammed D. , Al-Ajlan Raed A. , Al-Hajri Nasser M. , Al-Quwaisim Hussain A. , Zamka Saleh I. , Al-Subaie Fehead M. , Green Todd A. , Al-Hajri Muhammad A. , Al-Meshal Fahad M. , Al-Shammari Nayef S. , Sagr Hani , AlJedawi Raed
Published: February 2017

This paper presents the success story of an innovative milling operation on a stuck-closed tubing master valve performed with electric line technologies. This field application has resulted in restoration of well accessibility, enabled well control, and saved costs related to rig intervention. The paper also documents lessons learned and recommends proper operational procedures related to future similar rigless operations, specifically with regards to well control and barrier philosophy.

A stuck-closed surface valve in a live well is treated with extra caution as it presents a serious and challenging well control issue. Such a situation often calls for immediate intervention to restore well accessibility and reestablish well integrity barriers. The stringent well control requirements of the oilfield operator make the operational design and corresponding job execution even more challenging. In this case, Well-A is a land based vertical oil well on which the master gate valve was stuck and non-functional in the closed position. The pressure bellow the valve was last measured to be 1200 psi, a relatively high shut-in wellhead pressure compared to other offset producers in the same field. The wellhead was equipped with two carbon steel master gate valves, in addition, to the swap valve. The lowermost gate valve is the stuck valve, hence, preventing access to the well. Several attempts to repair and grease the valve body and stems were unsuccessful. Accordingly, the oilfield operator has decided to mill the gate valve, secure the well, and then replace the entire tree.

The uncertainty in the well pressure below the master valve posed a significant operational risk. This is due to the impact of well fluid pressure force on the electric line rig-up after the gate valve is milled. Therefore, job planning, design, and execution were guided by a risk based and comprehensive contingency plan that accounted for all probable well control scenarios. The rig-up consisted of coiled tubing flanged risers, annular blowout preventer, Shear/Seal ram, and wireline blowout preventer in order to ensure the presence of adequate well control barriers throughout the operation. Adhering to a ‘safety first’ attitude, the operation was concluded successfully and met its said objectives. The successful massive undertaking of such critical well intervention operation has marked a new milestone in rigless well interventions.
Advanced Live Well Deployment System Enables Remedial Sand Control Solution
Authors: McClean Charlie , Hillis Parry , Zuklic Stephen , Ross Colby , Kidd Peter
Published: February 2017

In producing fields in moderately consolidated sandstone reservoirs, at any given time it is possible if not likely to have wells underperforming or even shut-in due to sand production. Later in the life of these fields, this issue becomes even more significant. Often times the reserves don't justify the economics of a full rig workover or the productivity risk of well kill operations. In these cases, the only option to restore productivity is utilizing through-tubing methods, deployed into the live well. Historically these systems have presented significant limitations in terms of interval length and reliability. However, by utilizing an advanced deployment system to eliminate mechanical risks and length limitations of typical through tubing systems, and by integrating this with a detailed, analytical approach to sand control selection, the benefits of live-well deployment can be realized without sacrifice in terms of installation reliability or long-term productivity.

A detailed engineering and testing process was applied to insure ruggedness and ease of use in the field on the mechanical deployment system to allow virtually any length assembly to be deployed using conventional coiled tubing BOP equipment. Concurrently, a thorough analysis is conducted to understand sanding tendencies across the interval and particle and flow characteristics in order to select and optimize sand screen characteristics as well as isolation devices to compartmentalize the interval for maximum well life. The paper will demonstrate multiple applications of the resulting system which allowed efficient installation across large producing intervals without the introduction of kill weight fluids, eliminating the associated productivity damage and risk. The operations were completed without NPT and the associated costs. The active sand control design and the detailed producing plan enabled production above targeted rates maintained to date.
Subsea Coiled Tubing Acid Stimulation Operation Using CT Tractor in Angola
Authors: Rajamani Karthik , Schwanitz Brian
Published: February 2017

An Angolan operator needed to perform a coiled tubing (CT) acid micro-wash stimulation on a subsea sand screen completion in order to improve production. The CT simulation showed that the coil would not reach the objective, which was the bottom screen, even with friction reducers, without the assistance of additional forces. The operator chose to deploy a downhole tractor to provide a pulling force to achieve the desired depth. However, this horizontal well had debris which prevented reaching the objective and required changing strategies to accomplish the job.

A downhole tractor can be powered by pumping fluids down the coiled tubing, driving a turbine which powers the hydraulic systems in the tractor. The drive fluid will then pass through the tractor and out the bottom of the tool to provide the treatment. Surface testing is performed prior to the job to determine at which pumping rate the tractor will be engaged and disengaged. This testing is performed with and without treating nozzles to gauge tool performance and expected pumping rates for tractoring and treating.

In this Angolan operation two runs were required to reach the bottom screen due to debris fill in the completion preventing passage during the first run. On the second run the CT provider used a nozzle that could both clean the well and treat in the same run. This operation demonstrates the effectiveness of using CT tractors, which are under-utilized in the industry, to achieve extended reach beyond the normal CT range. It also demonstrates the quick mobilization and same day deployment, as well as problem solving that can occur when service companies (CT provider and tractor provider) work closely together.
Best Practices in Pre-Fracturing Coiled Tubing Intervention Operations Increase Success Rate of Hydraulic Fracturing Treatments
Authors: Guizada Pablo , Rahim Zillur , Al-Kanaan Adnan , Al-Rashed Ahmed , Kayumov Rifat , Arifin Mohammad , Al-Jalal Ziad
Published: February 2017

Well stimulation and intervention are typical activities to enhance the productivity of gas-bearing sandstone reservoirs and meet the increasing demand for energy. Many wells target sandstone formations that require stimulation to produce gas at an economical rate. Proppant fracturing is the preferred stimulation method for such reservoirs because it creates highly conductive pathways between the wellbore and the reservoir. Prior to any fracturing treatment, sufficient injectivity at an acceptable bottomhole treating pressure (BHTP) needs to be established. Depending on the reservoir quality, the task of breaking down the formation and establishing a sufficient injection rate may sometimes be challenging due to the high in-situ stress and compressive strength of the reservoir rock. Formation breakdown pressure can exceed the completion limitation due to stress alteration zones around the wellbore. For such cases, interventions using coiled tubing (CT) are often required to proceed with the hydraulic fracturing operation.

Two well-known remedial CT treatments are typically used to address wells with high breakdown pressures or low injection rates. The first is treatment by chemical means. Chemicals containing organic solvents or acids are squeezed into perforated intervals in the wellbore; subsequent soaking of the well with such chemicals can help remove some of the near-wellbore damage induced by drilling. The second is treatment using a mechanical approach; abrasive fluids containing gelled fluids and sand are jetted at high pressures through a nozzle at the target depth to create a cavern that connects the wellbore with virgin, non-stress-altered sections of the reservoir. More than 10 interventions performed over the past five years are analyzed in this paper. These include both abrasive jetting and chemical squeeze job techniques. Analysis indicates that only half of the abrasive jetting jobs were successful, and none of the chemical squeeze treatments provided positive results. Based on detailed analysis, ways forward were determined that will improve the success ratio for remedial actions using CT, including employing fiber-optic real-time telemetry to precisely place the bottomhole assembly and perforating with CT to optimize operational efficiency.

This paper provides an analysis of the well intervention practices that aid fracturing operations and prevent challenging situations such as high breakdown pressure that result in unsuccessful fracturing treatments. The knowledge obtained from this analysis can be extended to other regions where similar breakdown challenges exist.
A New Record for a Rigless Completion Campaign Through Efficient Coiled Tubing Hydrajet Assisted Fracturing Operations in a Mature Field in Northeastern Colombia
Authors: Jaimes Mariana , Bahamon Jorge I. , Mora Edgar , Campo Pablo , Reina John F. , Orozco Alex O.
Published: February 2017

This paper addresses issues concerning treatment execution and discusses results from successful coiled tubing (CT) hydrajet assisted fracturing (HJAF) treatments performed during a campaign in a mature oil field located in northeastern Colombia.

The Tibú field is a mature field in northeastern Colombia having low-permeability reservoirs that necessitate stimulation techniques, such as hydraulic fracturing, to increase production by increasing the contact area of the producing intervals. Additional challenges exist, including small well location pads, complex community relationships, and security problems that inhibit simple, fast, and efficient operations. To address these issues, a solution was proposed involving a blend of conventional proppant fracturing with the versatility and efficiency provided by a CT-deployed hydrajet perforated pinpoint stimulation method. These operations included well cleaning using slow-rotating wash tools and correlation for depth control using a gamma ray/casing collar locator.

More than 40 wells have been completed using CT HJAF treatments in this field. Some technical advantages provided by the application of this technique are a higher perforating efficiency and a significant reduction in near-wellbore (NWB) friction, yielding reduced risk of premature screenouts, enabling higher pumping rates, and generating longer fractures. Post-fracturing oil production results met expectations for this mature oil field, proving the economic viability of this technique for successful multistage hydraulic fracturing in a short period of time. For most of the wells, all completion activities, including up to three fracturing stages, were performed in four days.

This paper shows how the proposed CT application for HJAF operations can yield significant benefits and improve the level of sustainability in these types of mature oil fields.
Employing Effective Water Treatment with New String Technology in the Eagle Ford to Mitigate String Failures
Authors: Kakadjian Sarkis , Nwachukwu Raymond
Published: February 2017

This paper reviews steps taken to mitigate coiled tubing string failures resulting from microbial-induced corrosion (MIC) in the Eagle Ford by initiating an effective water treatment process alongside the use of coiled tubing with bias weld in sour fatigue similar to base tube performance.

Premature failures of coiled tubing strings can be capital intensive for most coiled tubing companies in the current oil and gas market. In 2015 there was a total of three string failures resulting from MIC in the Eagle Ford—with an estimated cost of USD 750,000. MIC has been implicated in few corrosion related challenges in the well service industry in the past.

The water treatment process was implemented in field on 21 December 2015. The mitigation process involved treating the circulating fluid in the fracturing tanks on location with chlorine dioxide, peracetic acid, or BDNP quick killer biocides. These are combined with glutaraldehyde or combination solution of glutaraldehyde and quaternary ammonium (glut/quat combo) for longer term bacterial control at the start of each job. Water samples of the circulating fluids are taken within 8 hours to get the relative light units (RLU), which determined the proper time to re-treat the water on location. RLU values were also correlated to typical sulfur reducing bacteria (SRB) and acid producing bacteria (APB) levels in South Texas. The water treatment process has been administered, along with the continuous metering of the bacteria and introduction the new coiled tubing technology, for 12 months with no string failure has been encountered. Further analysis of the effectiveness of the treatment will be conducted later in the string life when the involved strings are retired.
Simultaneous Capillary Pressure and Wettability Determination for Tight Bakken Cores Using an Ultra-High-Speed Centrifuge
Authors: Luo Peng , Li Sheng
Published: February 2017

Capillary pressure and wettability play crucial roles in controlling fluid flow and distribution in tight/shale reservoirs with its nano- to micrometer-scale pore sizes, such as the Bakken formation in the Williston Basin. Because wettability reflects the interactions between rock surfaces and fluids, the introduction of external fluids during drilling, completion, and enhanced oil recovery processes may possibly alter wettability through chemical adsorption on rock surfaces. Therefore, accurate determination of Bakken formation wettability, particularly its alteration caused by different injection fluids, is extremely important in the Bakken production process. In this study, a state-of-the-art ultra-high-speed centrifuge was employed to measure capillary pressures and examine the wettability of Bakken cores by calculating the USBM (United States Bureau of Mines) wettability indices. Cores saturated and aged with formation brine or surfactant solutions were first injected with Bakken crude oil (i.e., drainage process). Then the fluids in the cores were displaced by brine or surfactant solutions to obtain the imbibition capillary pressure curve. Multi-speed measurements were conducted using the centrifuge to determine the capillary pressure between the crude oil and brine/surfactant solutions. Wettability and its alteration after surfactant saturation were quantified by analyzing different sets of wettability indices calculated from capillary pressure curves. The experimental results revealed that wettability alteration caused by surfactant adsorption on rock surfaces tended to change the rocks from water-wet to a more neutral-wet status, while the aging process partially restored the cores to water-wet again.

For unconventional tight cores such as Bakken, the ultra-high-speed centrifuge method presents several distinct advantages over the commonly used mercury injection capillary pressure (MICP) method combined with other wettability measurement methods: (1) actual reservoir oil and brine are used, so that results are more representative of field conditions; (2) it is a non-destructive method so that core plugs can be reused to study wettability alteration caused by chemical additives; and (3) capillary pressure, wettability, and relative permeability can be obtained from the same set of measurements.
Flow Behavior and Viscous-Oil-Microdisplacement Characteristics of Hydrophobically Modified Partially Hydrolyzed Polyacrylamide in a Repeatable Quantitative Visualization Micromodel
Authors: Guo Yongjun , Liang Yan , Cao Miao , Feng Rusen , Zhang Xinmin , Li Huabing , Hu Jun
Published: February 2017

To profoundly investigate the flow behavior and viscous-oil-microdisplacement characteristics of hydrophobically modified partially hydrolyzed polyacrylamides (HMHPAMs) as well as the effect of associating monomer content on those behaviors and characteristics, compared with partially hydrolyzed polyacrylamide (HPAM), the flow experiments through three serial mounted flat-sand-inclusion micromodels and the viscous-oil-microdisplacement experiments in both homogeneous and interstratified connected heterogeneous repeatable quantitative visualization micromodels were conducted by use of a series of polymers with varied associating monomer content (0–1.0 mol%) at similar viscosity within all shear rates concerned. The results obtained from flow experiments show that the resistance factors (RFs) and residual resistance factors (RRFs) generated by HMHPAMs were noticeably higher than those of HPAM, and the RFs and RRFs exhibited significant permeability dependence and increased with associating monomer content. The greater RFs and RRFs for associative polymer might not be mainly caused by polymer adsorption or retention but mostly caused by increasing aggregate sizes. At concerned permeabilities (1.1–6.1 µm2), all injections of HMHPAMs could tend to be stable, which indicates that all HMHPAMs could propagate deep into the porous media. The viscous-oil-microdisplacement experiments regarding the visualization micromodels with varied permeabilities (and permeability contrasts) provide new insights into the viscous-oil-microdisplacement characteristics of HMHPAMs, such as the piston-like displacement and profile modification. In homogeneous models, under different permeabilities (1.1–6.1 µm2), the variations of final viscous-oil recovery first increased and then decreased as a function of increasing hydrophobe content, and the hydrophobe content of the polymer to obtain maximum oil recovery enhanced with increasing permeability. This might qualitatively indicate that a constant permeability matches an optimal content of hydrophobic groups. At permeability contrast of approximately three, the HMHPAM with lower hydrophobe content (0.2 mol%) could obtain the maximum viscous-oil recovery. In contrast, the maximum viscous-oil recovery was achieved by the HMHPAM with higher hydrophobe content (1.0 mol%) at a contrast of approximately five. The HMHPAM with higher content of hydrophobic groups is suitable for the significant heterogeneity.
Vestibular sensory dysfunction: neuroscience and psychosocial behaviour overview
Authors: Kreivinienė Brigita
Published: February 2017

The objective of the submitted contribution is to describe one of the sensory dysfunction - the vestibular system. The vestibular system is crucial sensory system for other sensory systems such as tactile and proprioception, as well as having tight connection to the limbic system. Vestibular sensory system has significant role for further physical, emotional and psychosocial development. Descriptive method and case analysis are applied in literature based research methodology. These methods are most appropriate as far the vestibular dysfunctions not always are recognized in young age even though are seen as high psychoemotional reactions (psychosocial behavior). The vestibular dysfunctions in young age can be scarcely noticeable as far more often they tend to look like "just high emotional reactions" as crying, withdrawal, attachment to mother etc. which could be sensed as normal reaction of young child. Detailed vestibular sensory dysfunction analysis is presented, also explanation of the neurological processes, and predictions are made for the further possible interventions.
Psychological characteristics of paralympic athletes’ self-realisation
Authors: Kokun Oleg M. , Shamych Oleksandr M.
Published: February 2017

The Paralympic sport has become an important tool for post-traumatic recovery, adaptation, integration and social inclusion of people with disabilities. Disabled people involvement into sports activities has important social implications not only for a person but also for society as a whole. Due to relative "youth" of the Paralympic sports, there are no enough studies aimed at creation of necessary scientific support not only for full-scale trainings and competitions of Paralympic athletes, but also  for provision of full integration of Paralympians into society with the means of the Paralympic Sports, which is extremely important. High importance of psychological and socio-psychological research in this context is obvious. The article presents the results of our research aimed at identifying of common characteristics and factors of Paralympic athletes’ self-realization in order to promote the efficiency of trainings and competitions and full-scale integration into society
THE SIGNIFICANT CONTRIBUTION OF ISLAMIC RELATIONSHIP MARKETING PRACTICE IN MALAYSIAN TAKAFUL INDUSTRY TOWARDS DETERMINING CUSTOMER GRATITUDE, TRUST, AND COMMITMENT
Authors: Marhanum Che Mohd Salleh
Published: February 2017

Parallel to the achievement of the Takaful industry, agency system becomes the main medium utilised by the industry to educate the public and assist them about future financial preparation. As a mirror to an Islamic type of insurance, Takaful agents play significant role not only to sell the Takaful products, but also to behave according to the Islamic norms in front of their customers. Thus, this research is conducted to introduce new concept of Islamic relationship marketing (IRM) and investigates its significance towards customer gratitude, trust, and commitment in the industry. A total of 741 of Family Takaful customers in Klang Valley area have participated in the survey conducted in this study. Few statistical analyses were performed to confirm the proposed measures of IRM including descriptive, exploratory factor analysis (EFA), measurement model, and structural equation modelling (SEM) analysis. Through EFA and measurement model, four variables were confirmed to measure the IRM which are Islamic ethical behaviour, social, structural, and financial bonds. Furthermore, these measures of IRM have significantly affected customer gratitude, trust, and commitment via SEM analysis. This study serves as a starting point to promote new approach of marketing in the Takaful industry based on the Islamic norms. It basically aims to tackle the needs of Takaful participants which should be taken care by the Takaful agents as to ensure both of these parties receive benefits in the Takaful contract.
Penyusunan dan Pengembangan Alat Ukur Employee Engagement
Authors: Titien Titien
Published: February 2017

Abstract: This research was aimed to develop an instrument which can measure employee engagement score, which is based on Schaufeli’s theoretical framework. The previous instrument which was called Utretch Work Engagement Scale (UWES) was developed using content and construct validity. The content validity test was done by assessing some experts and using Aiken’s V, while construct validity was proved by item total correlation and factor analysis. Content validity test was conducted by getting input from fifteen experts in Psychology to evaluate the contents of 32 items. The Aiken’s V was used to evaluate the coefficient of each items (in which good range was from 0,645 to 0,98). The overall internal consistency was assessed using Cronbach alpha which showed the coefficient of reliability of 0,934 after deleting the items below 0,4, whereby leaving only 22 items for conducting the construct validity. Confirmatory factor analysis was done using factor analysis. 135 staffs in one of Plantation Company in Balikpapan were participated in this study. The confirmatory factor analyses produced a cross loading factors between three aspects of employee engagement which after confirming back to blueprint remaining only 8 items, which is distributed into 4 items for vigor, 2 items each for dedication and absorption.

Abstrak: Penelitian ini bertujuan untuk mengembangkan instrumen yang dapat mengukur skor employee engagement yang didasarkan pada kerangka teoritis yang dikemukakan oleh Schaufeli. Instrumen sebelumnya dikenal dengan Utretch Work Engagement Scale (UWES) yang dikembangkan dengan menggunakan validitas isi dan konstrak. Validitas isi diuji melalui judgment dari para ahli di bidang Psikologi dan menggunakan Aiken’s V, sedangkan validitas konstrak dibuktikan dengan korelasi item-total dan analisis faktor. Validitas isi diperoleh dari 15 orang yang ahli di bidang Psikologi untuk mengevaluasi isi dari 32 item. Aiken’s V digunakan untuk mengevaluasi koefisien dari setiap item (range yang baik berada di rentang 0,645 sampai 0,98). Konsistensi internal diperoleh melalui alpha Cronbach dengan koefisien reliabilitas sebesar 0,934 setelah item-item yang memiliki nilai di bawah 0,4 dikeluarkan. Total item yang tersisa berjumlah 22 item untuk kemudian dilakukan uji validitas konstrak. Confirmatory factor analysis dilakukan melalui analisis factor. Sebanyak 135 staf di salah satu Perusahaan Plantation di Balikpapan berpartisipasi dalam penelitian ini. Hasil analisis factor menunjukkan adanya factor yang saling tumpang tindih antara ketiga aspek dari employee engagement, yang setelah dikonfirmasi kembali ke blueprint menyisakan sebanyak 8 item, 4 item untuk aspek vigor, 2 item masing-masing untuk aspek dedication dan absorption.
Kerendahhatian dan Pemaafan pada Mahasiswa
Authors: Kusprayogi Yogi , Nashori Fuad
Published: February 2017

Abstract: This study aims to determine the correlation between humility and forgiveness in students. Respondents in this research are 252 students majoring in Psychology, Faculty of Psychology and Social and Cultural Sciences, Islamic University of Indonesia, with ages range from 17 to 24 years old. The hypothesis put forward by researchers is that there is positive correlation between the variables of humility and forgiveness in students. The research data in this study were analyzed using analytical techniques and product moment correlation from Karl Pearson; that is used to examine the relation between variables. The results showed that there is a positive correlation between humility and forgiveness (r = 0. 508 and p <0. 05) with the contribution of humility on the forgiveness of 25. 8%. Other results showed that there are different aspects of humility that contribute to forgiveness, in terms of demographic variables of age and gender.

Abstrak: Penelitian ini bertujuan untuk mengetahui hubungan kerendahhatian dan pe­maafan pada mahasiswa. Responden dalam penelitian ini adalah 252 mahasiswa jurusan psikologi, Fakultas Psikologi dan Ilmu Sosial Budaya Universitas Islam Indonesia, dengan rentang usia 17-24 tahun. Hipotesis yang diajukan peneliti adalah adanya hubungan positif antara variabel kerendahhatian dan pemaafan pada mahasiswa. Data yang diperoleh dalam penelitian dianalisis dengan menggunakan teknik analisis dan korelasi product moment dari Karl Pearson yang digunakan untuk melihat hubungan antar variabel. Hasil penelitian menunjukkan bahwa ada korelasi positif antara kerendahhatian dan pemaafan(r= 0, 508 dan p<0, 05) dengan kontribusi variabel kerendahhatian pada pemaafan sebesar 25, 8%. Hasil lainnya menunjukkan ada perbedaan aspek kerendahhatian yang berkontribusi pada pemaafan ditinjau dari variabel demografi usia dan jenis kelamin.

 