bluuebunny/crossref_metadata_2025_split huggingface dataset:
Managing Shallow Gas for Offshore Platforms via Fit-for-Purpose Solutions: A Malaysian Case Study
Authors: Huang N. N. , Girsang C. H. , Mansoor M. R. 
Published: March 2018

Abstract
Shallow gas seepage was first spotted at a central processing platform offshore Malaysia in 2010, acknowledged as Platform T in this paper. Frequent monitoring of the gas seepage was performed through ROV baseline survey and a comprehensive geophysical survey was conducted to understand the characteristics of the gas seepage and to ensure that the integrity of the foundation at Platform T was not compromised. The origin of the gas could not be ascertained at that point of time.
A soil investigation campaign was performed in 2016 to study the origin of the gas seepage. Two boreholes were drilled; a composite borehole to 150m below seabed for the purpose of soil sampling and in-situ testing and a pilot hole to 155m below seabed, which was later converted to a fit-for-purpose relief well as an alternate migration path for the gas. During the soil investigation campaign, dissipation tests were performed at several layers which were potentially the source or migration path for the gas. Five soil samples were segregated for headspace test to identify the gas type which subsequently can be used to identify the origin of the gas.
Dissipation tests performed at four depth intervals indicates pore water pressure less than 20% of the vertical effective stress and appear to continue decreasing if the test had not been stopped. It was concluded that a low to negligible amount of excess pore pressure exist in clayey silt layers. Results from headspace test show presence of methane corresponding to the clayey silt layers as reported in the boring logs. The gas most likely comes from biogenic sources, feeding on organic matter in situ over a large depth range.
It is unlikely that there are large pockets of gas in the soil due to its homogeneous clayey nature and the lack of excess pore pressure in other permeable clayey silt layers encountered. Instead, it is more likely that when pore water at certain depth encounters a more permeable path, such as a borehole, it rises up through this path due to the temperature gradient in the soil. As the water rises, the pressure decreases, which could cause gases dissolved in the water to come out of solution and form bubbles. As a result, the gas will have no impact on the integrity of the foundation at Platform T.
The fit-for-purpose relief well design as well as adopting headspace testing can be used to address the shallow gas issue at Platform T in a cost-effective and efficient manner.
Full-Scale Verification of the Hydrodynamic Motions of a Floating Facility
Authors: Zed M. , Milne I. A. 
Published: March 2018

Abstract
Quantifying the hydrodynamic motions of a floating facility is critical for ensuring its safe and efficient operation. The ability to obtain estimates of the motion response charactersitics using a numerical approach to estimate the seastate is particulary attractive for sites in which limited observational wave data are available. Validation of such a numerial approach using full-scale data is however, desirable in order to establish its accuracy and limitations. To this end, this paper presents a case study where numerical estimates of the dynamic motions of a drillship were validated using high quality dynamic motion records acquired during the drilling campaign. The model comprises a hindcast of the directional wave spectra and numerically derived hydrodynamic response characteristics of the ship. The performance of the model is evaluated using a range of selected seastates which were observed during the drilling campaign. It is demonstrated that reliable estimates of the motions of most interest for a drilling operation can generally be obtained, thus providing support to the use of the provided numerical approach for conducting operability assessments for floating facility planning purposes.
A Semi-Analytical Model for Simulating Fluid Flow in Naturally Fractured Reservoirs with Non-Homogeneous Vugs and Fractures
Authors: Wu Yonghui , Cheng Linsong , Huang Shijun , Jia Pin , Fang Sidong , Wang Suran , Xin Jing , Xu Bingxiang 
Published: March 2018

Carbonate reservoirs are characterized of fractures, vugs and cavities. These vugs have a large attribution to reserves of oil and gas. And the fractures provide effective paths for fluids flow in the reservoir. Triple porosity model is an effective conceptual method to capturing rock matrix, vugs and micro-fractures connecting them. However, these fractures and vugs are always non-homogeneous. Macro fractures and vugs cannot be handled with continuum for their low density and high conductivity.In this approach, the triple porosity conceptual model is implemented to characterize rock matrix, micro vugs and fractures. To capture the heterogeneity of fractures and vugs, macro fractures and vugs are represented explicitly with discontinuum model. The boundaries of macro vugs and macro fractures are discretized into several elements. Boundary element method is employed to handle flow into macro fractures and vugs. Finite difference method is applied to handle flow within macro fractures. The flow within macro vugs are assumed to be in pseudo-steady state.With a simple discretization of the boundaries of macro vugs and macro fractures, the proposed model is shown to efficiently simulate the behavior of fractured carbonate reservoirs with heterogeneity. The computational accuracy is demonstrated using an analytical model. On the basis of the proposed model, the effect of heterogeneity of macro fractures and vugs on pressure transient behavior is analyzed. The results show that macro fractures and vugs cannot be handled with triple-continuum models analytically. There will be several "dips" on the derivative of pressure curve if macro vugs are discretely handled. And discretely handling the fractures and vugs will make the calculated dimensionless pressure and the derivative lower than calculated with tripe continuum models. Increasing the porosity of macro vugs, the pressure and the derivative will go down in the flow regimes dominated by macro vugs. The conductivity of macro fractures has a great impact on almost all the flow regimes except boundary dominated flow regimes.The novelty of the new model is in the ability to model the transient behavior carbonate reservoirs with non-homogeneous fractures and vugs. Furthermore, it provides an efficient method for characterizing the heterogeneity of multi-scaled fractures and vugs.
Bongkot South Field Multilayer Reservoirs Retrograde Gas Condensate Model
Authors: Charoenniwesnukul Kritsada , Tan See Heow 
Published: March 2018

Abstract
BONGKOT South field is a multilayer retrograde gas condensate reservoirs field. The condensate –gas ratio (CGR) and condensate production forecasts are a major challenge of the field especially with monobore well completion which has limited zonal contribution data. This paper describes how the pressure-based CGR framework with integrated reservoir engineering data analysis is introduced to improve the forecast accuracy and enhance reservoir behavior intuition compared to the existing empirical methodology, CGR versus cumulative production.
The framework adopts the pressure-based CGR correlation which can model the retrograde condensation while maintaining simplicity for practical use. The proposed framework is split into 2 sections. The producing CGR parameters are established through history matching with actual production data using integrated information to enhance intuition on the CGR behavior which improve the accuracy of the CGR matching and forecast. The non-producing CGR is estimated using the established CGR correlations which were constructed based on the sample with CVD analysis and all single reservoir production data. The estimated CGR then apply to the simulator result to get the condensate forecast.
The forecasted field condensate rate during plateau period ranges between 8,000 to 11,000 STBD with single reservoir initial CGR and field average producing CGR varies in range of 15 – 120 STB/MMSCF and 17-28 STB/MMSCF respectively. Field blind test was also performed to validate the framework which shows mismatch in a total condensate volume of less than 3% over a total raw gas volume of 47 BSCF.
Results from various well-level CGR history match show different CGR decline behaviors of retrograde gas condensation and vaporization at lower reservoir pressure. The matching of such behavior can be achieved by the proposed framework which adopts pressure-based correlation while the existing production based correlation cannot.
The proposed framework has demonstrated that BONGKOT South operators can accurately predict well producing CGR for prudent reservoir management and development. Well-structured integrated data analysis during CGR history match provides better intuition into reservoir behavior which could guide engineer to better reservoir management decision. The established CGR trend could also be used by external optimizer module, e.g. LINOPT, as CGR decline input to better optimize the longer-term condensate recovery.
Geomechanical Stability and Overall System Behavior of Sloping Oceanic Accumulations of Hydrates Responding to Dissociation Stimuli
Authors: Moridis George J. , Queiruga Alejandro F. , Reagan Matthew T. 
Published: March 2018

Abstract
The objective of this study is to quantitatively assess the flow, thermal and geomechanical response of sloping oceanic accumulations of hydrates to stimuli that can induce dissociation, such as depressurization-induced gas production activities, with emphasis on the evaluation of the geomechanical stability of the well assembly and of the reservoir. Using numerical simulation, we analyze the coupled flow, thermal, thermodynamic, chemical and geomechanical processes involved in the response of sloping hydrate accumulations exposed to dissociation-inducing stimuli associated with depressurization-based activities for the production of gas from the hydrate-bearing sediments. The study includes a sensitivity analysis of the system behavior to the angle of the slope in order to determine its effect on the system behavior, and cover the system long-term behavior following the cessation of the stimuli.
We determine that gas production from hydrate-bearing media may cause subsidence that increases stresses along the well and reduces gas production, but does not appear to enhance the risk of hillslope stability while production continues. The risk of oceanic landslides increases slightly after the end of gas production as a result of the increase in the pressure in the reservoir where the hydrate (which imparts the bulk of mechanical strength to the unconsolidated oceanic sediments) is depleted or exhausted, but at no time is the system stability compromised for any slope angle.
The paper provides an integrated quantitative analysis of the coupled processes that are involved in dissociating hydrates using themost advanced simulators, and makes significant contributions to the evaluation and risk assessment of potential problems associated with future production from oceanic hydrate deposits, in addition to providing insights that may lead to mitigation of the problems.
New Intelligent Circulating Sub: Cutting-Edge Technology for a Challenging Deepwater Operation
Authors: Balachandran Arun , Eren Sinasi , Abdullah M Zulhilmi , Lai Harni Farihah Bt M Safari , Tahoun Ahmed 
Published: March 2018

Abstract
In any coring job, a common challenge is to maintain good hole cleaning while using a reduced flow rate to prevent washout of the core samples. Without proper hole cleaning, the hole is exposed to cuttings accumulation which may lead to major problems such as induced losses and stuck pipe case. To ensure adequate hole cleaning during the coring operation in a PETRONAS Carigali Sdn Bhd (PCSB) deepwater well, a new multi-cycle circulating sub, Intelligent Circulating while Drilling (iCWD) was utilized.
iCWD was developed primarily to perform losses treatment, isolate hole sections and improve hole cleaning while drilling without the need to pull out of hole, through surface activation. The tool is unique as it does not require a drop ball for activation and can function in a minimum flow rate environment. In a deepwater operation, this is especially useful as the time saved can be translated into significant cost savings. A further advantage with the elimination of ball activation is that the coring operation which also relies on drop ball mechanism is not compromised by ensuring operational efficiency and reducing the risk of losing the core during the recovery.
Smart Communicative Cement: A Step towards the Future of Zonal Isolation
Authors: Melo Ricardo C. B. , Eid Ramy 
Published: March 2018

Abstract
The oil and gas industry, by default, has been pretty conservative when it relates to innovation and drastic changes in mind-set. Mainly focused on the costly drilling and completion steps, some of the "smaller" services have been ignored. As such, we have decided to take a deeper look at nano and micro sensored technologies in other industries and potentially replicate some of this innovation, allowing the industry to take "a step" closer to smarter zonal isolation.
In general, the industry is quite aware of well integrity issues that we face. Be it immediate (whilst drilling/completing), within the life of production or even during the abandonment phase. There are many statistics proving that on a global scale, there is well integrity and sustained casing pressure issues on about 30-60% of all drilled wells. And we can confirm that a majority of these are directly related to well-cementing, creating an immense impact(s), that can negatively influence overall HSE, loss of potential reserves and bottom line dollar-amount.
The ability to take a close look at well cementing has only proven feasible in a laboratory environment, beyond that, the knowledge and prediction of the actual state of the zonal isolation has proven difficult, confusing or costly.
Regardless of the improved best practices, enhanced logging tools or state-of-the-art technological advances in chemicals/systems – we still seem to have that unanswered "gap" – on what actually happened, when it happened and how to avoid it in the future.
This paper describes the background, the thought process and the potential advantage of the proposed well monitoring ideology and current R&D efforts to improve the cement isolation measurements and real time monitoring of its properties and integrity during the well life and after its abandonment, by sensoring it and communicating back to surface.
Simulation-Based Design for Load-Out, Transportation, and Installation of Offshore Topside Modules Based on Flexible Multibody and Collision Dynamics
Authors: Ham Seung-Ho , Roh Myung-Il 
Published: March 2018

Abstract
After an offshore topside module is constructed on land, it is moved to the transportation barge by the load-out operation. Once the module arrives at the field, the floating crane is used to install the module on the sub-structure such as the jacket. For the safe operation, methods for the load-out, transportation, and installation should be analyzed in advance. Flexible multibody dynamics which is theoretically based on ANCF (Absolute Nodal Coordinate Formulation), and collision dynamics which is based on the non-interpenetration constraints are developed for physics-based simulation. By using the developed program, we analyzed dynamic effects during load-out, transportation, and installation of the topside module. For the load-out operation, MTPs (Modular Transporters) are modeled to lift the topside module and to move toward the transportation barge. The transportation barge and the quay are connected by link beams which are modeled by flexible bodies. Finally, during the load-out operation, dynamic loads on the deck and the link beams are calculated. Secondly, during the transportation, dynamic loads due to the wave-induced motion between the barge and the module due to sea fastening are calculated. Thirdly, the motion of the module lifted by the floating crane is checked according to the environmental conditions. As a result, we can evaluate safe environmental conditions and dynamic loads.
Lightning Phenomena - Offshore O&G Facilities Not Immune
Authors: Yasir Ir. M Faudzi b M , Taib M Akmal b A. 
Published: March 2018

Abstract
In general, based world lightning map, Malaysia geographic location is in high density of lightning activities with average of 50 lightning flashes/km square. Lightning has been recorded as one of the factors cause of asset damage, fire and even fatality at offshore installations. A review of applicable lightning protection system requirement for offshore facilities and installations are not fully addressed by codes and standards. This paper describes the underlying basis for guidance of Lightning Protection System Solutions (LPS) for offshore installation from lightning strikes, their induced effects and secondary electromagnetic effects.
Influence of Hydraulic Connection Between the Hydrate Reservoir and Surrounding Rock on the Methane Production
Authors: Xia Yingli , Xu Tianfu , Yuan Yilong , jin Guangrong , Xin Xin 
Published: March 2018

Abstract
Natural gas hydrates (NGH) are considered as a clean energy which widely spread in marine sediments and permafrost regions. Numerical simulation is a convenient and economic way to study methane production from reservoir, a lot of previous simulations treated the hydrate reservoir as homogeneous layers. However, the underground environment is tend to be complexity, there may be a high permeability tub connect reservoir with surrounding rock, and the water of surrounding rock may flow into reservoir along the connection tub. In order to explore the effects of hydraulic connection between reservoir and surrounding rock on gas production, a 3D geological model based on logging data of Shenhu Area of the South China Sea is established. The different strength of connections were realized by constructing varying spatial distributions of permeability and porosity. Results show that in regions of strong hydraulic connection, the hydrate dissociation rate is higher than weak hydraulic connection zones, the relative permeability of gas is higher tan water because the gas saturation is higher relatively So reservoir having strong connection with surrounding rock may not be poured with large amount of water.
Boundary Detection Ahead of the Bit – A Sensitivity Study of Extra Deep Azimuthal Resistivity
Authors: Larsen David Selvåg , Boesing David , Hartmann Andreas , Martakov Sergey , Mumtaz Asim , Skillings Jon , Vianna Armando 
Published: March 2018

Abstract
The opportunity to detect boundaries ahead of the bit has long been a desire within the oil and gas industry as it would allow precise geo-stopping prior to entering unwanted formations and/or fluids. There are solutions already available such as the use of seismic applications. However these are for use on a different resolution scale, the accuracy needed for geo-stopping within meters of a formation boundary is lacking.
Extra Deep Azimuthal Resistivity (EDAR) has been widely used for geosteering and landing applications around the world utilizing the common methodology of looking around and predicting ahead (see, for example, Larsen et. al., 2016). This methodology has been very efficient in a horizontal drilling environment with fairly low dipping layers, typically when incident angles do not exceed 10-15 degrees. In such wells, the environment ahead of the bit is generally not changing abruptly and therefore provides only a minor contribution to tool response compared to the volume around the tool. For higher incident angles, the zone of interest is likely to be ahead of the bit. Here traditional looking around the wellbore and predicting ahead is no longer sufficient. The steep angle of approaching beds requires sensitivity ahead of the bit in order to detect and predict upcoming resistivity boundaries.
In this paper we will study the extended capabilities of the interpretation method currently used only in high angle and horizontal (HA/HZ) well applications. We will present sensitivity analysis of the theoretical capability of detecting ahead of bit with the different key factors determining the capability, such as sensor placement behind bit, formation resistivity and incident angle.
The study will show that the application range of EDAR can be extended from the 15° incident angle range to up to 90° incident angle. The extension allows using the service for low angle geo-stopping applications. The analysis is performed on theoretical data as well as a case study from a well in the Middle East.
Enhancing Operations with Digital Technology to Bring Expertise to Site
Authors: Oliver Philip RF 
Published: March 2018

Abstract
The proposed paper will examine the potential of remote working technology to overcome operational challenges, reduce mobilisation costs and enable collaborative working in real-time by bringing expertise located anywhere in the world to local sites through digital technology. The potential benefits associated with the technology are compared to traditional techniques using recent case study examples.
Following the ‘technology readiness levels’ approach used by NASA and other organisations, Wood took a methodical but expeditious approach to developing and testing remote working technology. Supply chain expertise was leveraged to identify suitable technologies (hardware and software) that met the stringent requirements of deploying such technology to oil and gas facilities. Once these technologies had been selected, initial office-based tests were completed, followed by deployment onshore and offshore for piloting. Valuable lessons were learned from piloting, and the technology refined. The so-called ‘eXpert’ system is now internationally deployed to onshore and offshore facilities and successfully embedded in day-to-day business.
The paper will detail comparative case study examples where this technology has been successfully applied. Key learnings are summarised as follows: The technology has the potential to better connect the workforce with data, processes and systems necessary for safe, efficient and more effective execution. It improves collaboration between colleagues located at different sites, facilities or offices and reduces disconnects and misunderstandings that can occur in distributed organisations. The hardware and software package is easy to use, requiring minimal user training and leading to swift adoption.The remote working technology reduces execution times for specific work scopes by 60%-90%, and significantly reduced mobilisation costs. By reducing the need for personnel mobilisation by helicopter once the technology is deployed to site, travel emissions can also be minimised.The ability to involve experts from anywhere in the world, in real-time, allows faster issue resolution, reduction of risk to personnel safety and avoidance of mobilisation costs.
Remote sites present some of the greatest operational challenges in the energy industry. Effective communication between offices and worksites is crucial to identify issues, diagnose problems and develop solutions. Frequently, teams of engineering specialists and decision makers are required to reach a conclusion, however getting these experts to site can prove difficult in terms of logistics and cost. This technology brings the knowledge and expertise of colleagues to site in a direct, meaningful and efficient manner.