bluuebunny/crossref_metadata_2025_split huggingface dataset:
Geomechanical Model from Subseismic Resolution Data
Authors: Purnomo Eko Widi , Ghosh Deva Prasad 
Published: March 2016

Abstract
This article demonstrates the extension of subseismic-driven earth elastic model into geomechanic domain. The geomechanical model is becoming uncertain as the impact of subseismic uncertainty. The detail and the uncertainty of the geomechanical model need to be quantitatively defined.
An innovative stochastic partial stacked seismic inversion is proposed to be combined with the geomechanical model built from well to address the problem mentioned. The stochastic inversion uses the energy attribute to control the misfit between the synthetic and true seismic through a Bayesian inference. The prior model of inversion is generated through a geometrical and geophysical perturbation of reflectivity model derived from apparent seismic amplitude. The perturbation is constrained by assigned wavelet, tuning and spectral analysis, and locally varying anisotropy to ensure the adequacy of both vertical and lateral resolution. A geomechanical low frequency model is built by calibrating the low frequency model predicted from the relative geomechanical properties (which is the extension of the relative elastic impedance) inverted from the primary inversion with the geomechanical low frequency model derived from the well log data. The absolute value of the geomechanical property is then estimated based on the frequency content matching between the calibrated relative geomechanical properties and the well log geomechanical model. The related uncertainty of the inverted geomechanical properties is assessed by employing the Markov Chain Monte Carlo (MCMC) sampling methodology.
The proposed method was test to predict the geomechanical model of a fractured volcanic rock basement of Malay Basin. The proposed combination approach between well log geomechanic and stochastic inversion based elastic impedance shows the critical challenge in modeling the geomechanic from subseismic resolution seismic data and promises a good solution. Compared with conventional deterministic inversion, the proposed stochastic inversion provides much better resolution both in lateral and vertical direction, and geologically more consistent. The detail inverted geomechanical properties, inherited by the detail inverted elastic properties, can be used to study the fracture of the potential fractured basement hydrocarbon reservoir.
Design Issues and Modeling Perspectives of Offshore Basin
Authors: Sung Hong Gun , Hong Seok Won , Kim Jin Ha , Yun Sung Hee , Cho Seok Kyu , Nam Bo Woo 
Published: March 2016

Abstract
Recently there are practical concerns for the design of offshore basins since a new large offshore basin named "Deep Ocean Engineering Basin" is under construction by Korea Research Institute of Ships & Ocean Engineering (KRISO). It is known that this would be the world largest one at this time moment. In this paper, we present a number of design issues and modeling perspectives of offshore basin. The main focus is given to basin size and depth together with major facilities for modeling ocean environments such as wave, current, water depth and wind.
Geomechanical Forward Modelling to Optimise Well Trajectories and Avoid Pre-Existing Fractures in a Malay Basin Producing Field, Offshore Malaysia.
Authors: Mohd Nor M. , Abdul Razak M. , Smith S. P. 
Published: March 2016

AbstractObjectives/Scope: When drilling a micro fractured formation, the fluid differential pressure for wellbore support can be lost and the unsupported formation may fail, causing losses, pack-off and instability. This may be minimized or resolved if the zones of pre-existing fractures are known and the trajectory is optimized to avoid them.In the Malay Basin, one structure of interest has undergone several periods of stress and faulting, at times, strike-slip in nature. Wrench faults in the area are causing compression and extension. This strain causes micro fractures and voids to be generated. The formation has a secondary porosity but seismic resolution does not allow the pre-existing fractures to be seen. By using a technique known as Geomechanical Forward Modelling (GFM), it is possible to determine natural fracture distribution and avoid these zones, thereby decreasing the risk of encountering instability caused by secondary porosity.The problems of borehole instability encountered in the area are demonstrated in wells, A1, A2 and A3. The most problematic well was A3. It had many incidents of pack off causing side tracks. In each case, the hole condition was better on side-tracks made higher up the well. It was considered that there is a 3 dimensional extent to the presence of micro fractures. The fracture intensity may have a vertical as well as areal extent. Sometimes wells crossing above or below a zone are not as difficult as through it.On wells that experienced pack off, cavings at the shaker had an abundance of linear breaks oblique to shale bedding surfaces and suggests the probability of pre-existing fractures. Pre-existing fractures were also seen on image logs.During planning for an appraisal well, zones with lower plastic shear strain were identified to the North and West of the planned well trajectory by applying GFM. The plastic shear strain profile along the planned trajectory suggested that the target depth will intersect a potential fractured zone. By moving the surface location by only 500 meters, the chances of encountering pre-existing fractures was significantly diminished.By applying Geomechanical Forward Modelling, (GFM), it is possible to determine distribution and possible locations of secondary fractures, too small to be determined from seismic. This allows for the selection of well trajectories to avoid these naturally fractured zones, thereby decreasing the risk of encountering instability from secondary porosity (pre-existing shear fractures).
Optimizing Drilling Parameters by Integrating Formation Collapse Gradient in Well Hydraulic Modelling to Eliminate Wellbore Mechanical Instability Problems
Authors: Benny B. , Usmar R. , Irawan F. , Setiawan A. 
Published: March 2016

Abstract
Formation collapse gradient is an important parameter for well design and drilling mud selection, especially in a field with history of wellbore instability problems. In modern well design, this gradient is easily neglected since its tendency to be lower than pore pressure gradient. However, some field studies in Indonesia showed that the collapse gradient may be higher than the pore pressure gradient which will result in an unstable well if the bottom hole pressure (BHP) is not well addressed.
In the event of formation collapse, the common drilling practice is to increase the mud weight (MW) being used to a level above the collapse gradient which is time consuming and very rigid operation. Meanwhile, Manage Pressure Drilling (MPD) offers a relatively more dynamic wellbore pressure control by adjusting the surface back pressure (SBP) applied to the annulus for a given MW. Instead of shifting the MW or changing drilling parameters, MPD provide adjustment to the required equivalent circulating density (ECD) or equivalent static density (ESD) based on formation collapse gradient. Additionally, in the event of mud losses due to high ECD/ESD, MPD technique simply lowers the SBP to decrease the BHP without the need to lower the MW.
This paper will utilize hydraulic simulation software to model the drilling window, considering not only pore and fracture pressure gradient, but also involving collapse gradient to optimize recommended MPD parameters including MW and SBP when drilling, pipe connection, and completing the well.
Formation of Project Management Institute Leads to Improved Project Delivery
Authors: Tait Alastair , Kadri Ramzi B. , Kamarudin Zainuddin B. 
Published: March 2016

Abstract
PETRONAS Carigali Sdn. Bhd.'s (PCSB) decision to set up its own Project Management Institute was in recognition of the need to achieve the level of project delivery performance, in terms of safety, cost, quality and schedule, to which it aspired. External benchmarking had shown that it was under-performing in relation to its peers. This paper will show how, during the lifetime of the Project Management Institute, the skill-base within the organisation was broadened and deepened, and project performance improved in comparison with other international operators.
The Economic Assessment of McT Multi Column TLP and Jacket Platforms Application in Multiple Marginal Oil Fields
Authors: Tahar A. , Nurtjahyo P. , Suardin J. , Chaniadi F. 
Published: March 2016

Abstract
Recent offshore drilling success in shallow water and marginal fields development has spurred a tremendous growth in new and innovative solutions that are required to reduce costs, shorten development schedules and exploit previously uneconomical fields. For the redevelopment of Brownfields, a cost efficient offshore production and drilling platform has to increase production capacity within existing field infrastructure. For the Greenfield development, the efficient platform has to offer cost and schedule savings for applications where conventional fixed jacket platforms are uneconomical or where site-specific design requirements or constraints need to be met.
In this paper, we will benchmark an emergent, proven and more cost-efficient technology - Multi Column TLP ("McT"), against the typically utilized offshore platform - "Fixed Jacket." McT is a proprietary technology, patented by Petroneering and its unique design is derived from the commercially-proven technologies of TLP (Tension Leg Platform) and Cell Spar, the two preferred solutions for deepwater development around the world. Having combined the inherent mobility of TLP and simplicity of Cell Spar, McT has now been developed to deliver both the operational reliability and production stability and can be re-used and re-located among disparate marginal fields that were not economically viable using the existing Fixed Jacket technology. This minimizes the CAPEX allocation for the oil & gas operator's individual marginal field project.
This paper will also discuss about the overall benefit of McT technology and its economic advantages for various field development plans (i.e.: of drilling & completion, fabrication to abandonment stages; from single to multiple marginal fields). Further assuming a similar OPEX of both technologies, the cost and schedule of each stage will then be examined and rationalized at different price points of oil. The resultant benchmarking metrics include the accumulative net profit increase over the life of the marginal field (at 5 years).
Remotely Operated Barrier Valve Provides Interventionless Solution for Offshore Vietnam Completion Campaign
Authors: McLeod Bruce , Chinh Nghi Nguyen 
Published: March 2016

Abstract
Considering the scope of work necessary to batch-complete six wells within a tight deadline, the initial outline for an offshore Vietnam completion program required multiple slickline well interventions, not only while on the rig critical path but also during simultaneous operations (SIMOPS). This high frequency of well intervention added considerable time, cost, and potential risk to the overall completion campaign, warranting incorporation of an alternative cost-effective interventionless concept.
Remotely operated barrier valves were evaluated and determined to be a low risk but high value-enabling alternative to running conventional plug-and-prong type barriers during the completion installation. The remotely operated valves' multiple open and close capabilities provided further efficiencies that could be achieved as part of the completion running phase, as well as during SIMOPS when the wells were flowed for cleanup and later suspended for four months until topsides were commissioned.
Two remotely operated barrier valves were pre-installed in their respective nipple profiles (one above the production packer and one below) and run in each of the six completions. The upper valve added value by allowing the production tubing, which included gas lift mandrels, to be pressure tested to full working pressure before setting the production packer. The lower valve facilitated circulating the well to underbalance fluid before setting the production packer and then allowed for subsequent setting and testing of the packer from above. It was later used as a deep-set barrier, allowing blowout preventer (BOP) retrieval and christmas tree installation on the rig critical path before performing further operational steps during the planned SIMOPS.
Using the remotely operated valves in the project provided significant rig time savings of 30 hours per well by eliminating 15 well interventions. This also contributed to reduced health, safety, and environmental (HSE) risks and non-productive time (NPT) potential that are historically associated with slickline-related activity.
This paper illustrates, in detail, the completion installation practice adopted and the many benefits and added value the technology provided to the overall project, both on the rig critical path and during SIMOPS.
Finite Element Modeling of Wet Lay-up CFRP Patch Repaired Corroded Offshore Steel Jacket Member
Authors: Setvati Mahdi Razavi , Mustaffa Zahiraniza , Shafiq Nasir , Isnadi Biramarta , Syed Zubair Imam 
Published: March 2016

Abstract
As the development and application of fiber reinforced polymer (FRP) composite materials to different engineering structures are increasing, composite patching techniques are being considered as alternatives to traditional methods of repair to Jacket-type steel structures. The present paper describes a developed finite element model (FEM) of corroded tubular steel member, representative of offshore steel jacket member, and a FEM of wet lay-up CFRP patch repaired corroded tubular steel member using ANSYS software and ANSYS Composite PrepPost (ACP), which is an add-on module to ANSYS software. The numerical study results reveal that the three-ply composite patch reduces the maximum von-Mises stress, maximum stress intensity and maximum shear stress of the corroded tubular steel member by approximately 20.6%, 18.2% and 18.2%, respectively. Moreover, ply-wise stress and strain results indicate that maximum tensile stress and strain was observed in the first ply and maximum compressive stress and strain was noticed in the third ply. Failure analysis demonstrated that under first applied load and moment there is no critical region or critical failure criteria in composite patch, but under increased axial load of 1300 KN, composite patch fails.
Interface Management - Key to Successful Delivery for a Large, Complex and Integrated EPC Offshore Project
Authors: Poddar Tushar , U Sue 
Published: March 2016

Abstract
Integrated Offshore oil and gas EPC project (IOEPC) is increasingly becoming tougher to manage, as project dimensions and definitions are ever expanding, in order to achieve cost effective field development within the stipulated time frame. The outreach of Interface Management (IM) links directly to all prime project elements to achieve project goals in terms of safety, Quality, schedule & budget. Robust project specific IM plan and procedure is the key document. Systematic model-based IM covering both internal & external interfaces helps to achieve excellent results in project performance. Comprehensive well documented milestone driven Interface Register addresses the flow of issue based information between ‘Requestor’ and ‘Responder’ at the appropriate time, is the essence of success in implementing model based IM system.
For a mega project of TIC &gt; 1.0 BUSD, the model needs to be software driven incorporating various value added algorithms. Web-based IM Module application is a preferred solution for managing remotely when stakeholders are in multiple locations. The benefits of implementing effective IM systems are numerous. The key determinant to derive the outstanding benefits of the IM system is to evaluate the impact in Scope-change, safety, QA/QC and associated risk before accepting data/information from the Responder. One can amply be benefitted by comprehending and adopting the systematic model based IM system. It can potentially save in the excess of tens or hundreds of millions of dollars by avoiding rework, delays, and subsequent production loss for managing integrated offshore mega projects. One of the key lessons learned is when IM is implemented, the possibility of the project success increases dramatically.
Improved High-Speed Mud Pulse Telemetry Performance Under Harsh Conditions
Authors: Emmerich W. , Brahim I. Ben , Akimov O. , Greten A. 
Published: March 2016

Abstract
Mud pulse telemetry (MPT) is the main real-time data transmission technology in oilfield drilling. Constant advances in technology have permitted the oil and gas industry to drill complex well paths and deliver valuable real-time formation measurements. New logging-while-drilling technologies have considerably increased the amount of information collected downhole and therefore the demand for real-time transmission bandwidth.
Reliable high-speed MPT with increased data rates is needed when utilizing complex bottomhole assemblies (BHAs) to deliver information without compromising the rate of penetration. When drilling deep wells with high-density and high-viscosity oil-based mud, transmitting data at high rates introduces challenges for MPT because of the higher signal attenuation and signal distortion. This paper describes enhancements to an MPT system. Improved signal processing at the surface and adjusted signal sequences are used to tune adaptive filters on the receiver side, enabling data transmission with physical data rates of 10 bits/sec and higher in these challenging conditions.
These adaptive filters adjust to new drilling conditions and changes in the MPT signal channel. A test sequence is sent regularly during operation of the system to improve adaptive filters. Improved noise cancellation techniques assist with automation of signal search functions. Filter performance is tested and saved into a database, enabling field personnel to optimize decoding quality at the rigsite. Challenging fields in different regions have successfully run this MPT system and improved decoding capabilities and increased performance compared to offset runs. In addition, the system provided overall higher reliability.
The improvements in MPT enable high-speed data rates in a wider variety of environments, as well as higher data rates in standard settings, lowering the overall cost of drilling wells.
Confronting Fluid Interpretation Challenges in Thin Laminated Sands with Nuclear Magnetic Resonance NMR Diffusion Maps
Authors: Ozobeme Charles C. , Gaafar Gamal R. , Altunbay M. Mehmet , Musa Faizah M. 
Published: March 2016

Abstract
The high prevalence of thin sand laminations in the Malay Basin is generally established and has the potential to unlock large resource volumes, not previously considered significant. Laminated sand intervals can sometimes have challenging fluid interpretation issues because of the masking of hydrocarbon response on resistivity logs. It is not uncommon to miss-out entirely on potentially producible hydrocarbon zones because of a failure to properly evaluate these laminated sands.
Fluid sampling may provide information on hydrocarbon types but there still remains the difficulty of establishing the interval limits of the hydrocarbon zones. The problem becomes more complicated when wells are drilled with oil based muds which has near similar response with the light formation oils in the Malay basin. In many cases, hydrocarbon zones are basically assumed to be in virgin state at the time of discovery, with single fluid contacts defining the reservoir fluid distribution. In fact, fluid sampling depths are often rationalised to one (1) or two (2) sample depths once the presence of hydrocarbon has been established. This simplistic assumption changes with turbidite systems, where laminated sends tend to compartmentalise gross reservoir sections with little indications on conventional logs.
In our case study, Nuclear Magnetic Resonance (NMR) 2D diffusion maps have been used to confront some of the fluid interpretation challenges. The NMR diffusion data acquired at selected station-stop depths were compared with results from the In-situ Fluid Analyzer (IFA) tool for defining distinct cluster patterns of different fluid types.
The results of the fluid interpretation were not only informative on the type of formation fluids but provided a commonly overlooked observation of free water occurrence within gross hydrocarbon intervals. This presence of free water within hydrocarbon sand package raises the possibility of postaccumulation flushing or prior migration. This has significant bearings on both the resource and reserves assessments of the hydrocarbon sands.
Seismic Resolution and Detection: Myth Versus Reality
Authors: Pathak Ravi , Rajput Sanjeev , Yin Khor Yin , Ring Michael 
Published: March 2016

Abstract
Understanding seismic resolution is critical when trying to build accurate reservoir models by integration of data coming from different disciplines. Lack of low frequencies in seismic data makes it band limited that limits its uses only for structural model but its availability and areal coverage suggests that it has valuable information to constrain the reservoir model. Increasing resolution to double through deterministic inversion can be achieved whereas additional constraints are needed to further increase this resolution. Thus, it is paramount to improve the resolution of seismic and detection of reservoir and be able to identify reservoir thickness and extension as accurately as possible in order to build reliable reservoir model. In this study, the uncertainty in seismic resolution versus detection and quantification of rock properties are investigated in terms of seismic inversion.
The framework of improving seismic resolution presented in this study is based on integrating seismic and well data through seismic inversion. It considers reprocessing of seismic data for frequency enhancement, pre-conditioning, rock physics modelling, high quality well-to-seismic tie and wavelet extraction, low frequency modelling, stratigraphic grid definition, property proportion distribution, geostatistical variograms and lithology trends. A detailed method description is provided that has proven to have high stability. By using a series of simple examples it is demonstrated that understanding seismic resolution is challenging and significant efforts are needed to obtain a realistic reservoir image.
Under careful control of the seismic wavelet characteristics including phase, frequency and amplitude; and provided the noise level of the seismic data is sufficiently low; useful information can be extracted from high resolution seismic inversion derivatives. It can serve the purpose of detecting beds much thinner than the conventionally accepted detection limit. The results reveal that high resolution seismic is not necessarily the data with high detectability.
The novelty of this investigation is in the ability to improve seismic resolution and detection through robust deterministic and stochastic inversion to solve the most important problem on the ‘level of detail that one can see in seismic’. The observations made on real data leading to the idea of explaining seismic resolution and detection myth versus reality.